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  • NOAA temperature record updates and the ‘hiatus’ « RealClimate
    with the longer running temperature records taken from engine intake channels in marine vessels As has been acknowledged by numerous scientists the engine intake data are clearly contaminated by heat conduction from the structure and they were never intended for scientific use The relevant passage from Karl et al seems to be In essence the bias correction involved calculating the average difference between collocated buoy and ship SSTs The average difference globally was 0 12 C a correction which is applied to the buoy SSTs at every grid cell in ERSST version 4 Notably IPCC 1 used a global analysis from the UK Met Office that found the same average ship buoy difference globally although the corrections in that analysis were constrained by differences observed within each ocean basin 18 More generally buoy data have been proven to be more accurate and reliable than ship data with better known instrument characteristics and automated sampling 16 Therefore ERSST version 4 also considers this smaller buoy uncertainty in the reconstruction 13 They seem to be reducing bias but I don t know enough to understand what they did Why would they apply a correction to buoy data equal to the difference between buoy and ship measurements I don t understand the context here or why a bias correction would work this way Curry suggests that the ERSST data is likely to be less careful or of lower quality than the already available HadSST3 data It would be helpful to know what you think about that as well It s not clear to me how a new dataset or new adjustments are marked as an advance or improvement upon existing sets other than adding 2014 or something 16 David Appell says 5 Jun 2015 at 12 46 AM So what to make of the 20 years of zero trend in both the RSS and UAH data for the lower troposphere 17 Clive Best says 5 Jun 2015 at 5 03 AM Very informative article thanks I have a technical question about your plot comparisons How do you renormalise the absolute values of the 3 temperature anomaly series NCDC GISS and Hadcrut4 when each uses a different seasonal normalisation period GISS uses 1951 1980 H4 uses 1961 1990 and NCDC uses the 20th century I believe BEST adopt a station dependent normalisation rather than a fixed time period which makes comparison even more tricky Response Each anomaly line is just baselined to a common period This is different and easier to re doing the analyses using a different normalisation period or method gavin 18 Barney says 5 Jun 2015 at 5 49 AM Can someone clarify the difference between the GISTEMP L OTI figures used for the graph titled No significant change in tend from 1998 which look like the ones here with 2014 higher than 2010 http data giss nasa gov gistemp tabledata v3 GLB Ts dSST txt and the GISTEMP figures in the graphical comparisons with CMIP3 and CMIP5 in which 2010 is the highest figure Response Possibly the colour bar is misleading but that is the Cowtan and Way record GISTEMP is kinda buried under the NCDC lines gavin 19 Steinar Midtskogen says 5 Jun 2015 at 6 15 AM The hiatus is so fragile that even those small changes make it disappear How is that statement different from the denier viewpoint that any warming over the past two decades is so fragile that just small changes make it disappear This looks like an admission of Curry s uncertainty argument to me Response No the long term warming trend is a much stronger signal relative to the non anthropogenic baseline gavin 20 mike hamblett says 5 Jun 2015 at 6 31 AM Shouldn t those who profess to know spend more time on the implications and the need for action There seems to be a lot of fiddling while Rome burns now which allows the skeptic loonies to promote the no need to worry angle 21 Mal Adapted says 5 Jun 2015 at 8 19 AM I was gratified to see that at least Major Meejuh outlet the New York Times gets it Author Justin Gillis has unequivocally abandoned false balance my italics The change prompted accusations on Thursday from some climate change denialists that the agency was trying to wave a magic wand and make inconvenient data go away Gillis knows a climate change denialist when he sees one quoting The Cato Institute a libertarian think tank The main claim by the authors that they have uncovered a significant recent warming trend is dubious said the statement attributed to three contrarian climate scientists Richard S Lindzen Patrick J Michaels and Paul C Knappenberger 22 Christopher Hogan says 5 Jun 2015 at 8 22 AM In response to post 16 Appell Some kind scientist here on RealClimate clued me in on some of the differences between the satellite data and the ground based series Maybe I should try to pass what I think I learned The RSS and UAH series attempt to infer temperatures from a thick slice of the atmosphere centering around 14 000 feet above sea level They may differ from the ground readings either because temperature trends at that height really do differ from ground trends i e both series are right but measure different things or due to purely technical issues i e one or both are wrong Temperature trend at circa 14 000 feet can differ from the trend at ground level Most importantly for the last 20 years issue El Nino has a stronger effect there The term of art is lower tropospheric amplification So compared to ground based series the satellite series substantially exaggerate the effect of El Nino with some significant lag This is why 1998 El Nino of the Century is a huge outlier in the satellite series Here is a link to two of Tamino s analyses of the satellite and ground series quantifying the degree of exaggeration of the El Nino in the satellite data as well as greater sensitivity to volcanic activity https tamino wordpress com 2010 12 16 comparing temperature data sets https tamino wordpress com 2011 01 06 sharper focus There are numerous other systematic issues related to real differences between temperatures in the upper atmosphere and temperatures on the ground A readable summary of those is given here http www climate lab book ac uk 2014 temperature lower troposphere Separately there are purely technical issues related to interpreting readings from aging instruments on satellites E g for years Christy and Spencer famously claimed no warming in the UAH data based on what turned out to be an algebra error in their corrections for satellite drift A discussion that goes deeply into the technical weeds can be found here http www realclimate org index php archives 2005 08 et tu lt The upshot is that people who fixate on the satellite series and a circa 1998 start point are centering their entire argument around a known flaw in the satellite data A flaw in so far as one uses it as a proxy for ground temperature trends which they invariably do Either they don t know that there s this well documented issue or more likely they just ignore it And so that s why the real scientists here likely won t take the time to address your post If you know even the least little bit about the satellite data which is how I characterize myself the lack of concordance with the ground series for short periods of time starting in 1998 is a non issue 23 Jose says 5 Jun 2015 at 8 28 AM You speak of heat going into the oceans but didn t the last IPCC report show model projections of ocean heat content vs observations and there was no extra heat in the oceans Response Not sure what you are referring to by the increasing heat in the oceans is abundantly clear https www nodc noaa gov OC5 3M HEAT CONTENT fig 2 especially gavin 24 Todd B says 5 Jun 2015 at 9 24 AM As an observation can I make a plea to anyone making model data comparisons that the bar separating hindcast from forecast always be included on these plots I m sure it s present on other graphs but this is the first time I ve noticed it It s a very important piece of information when talking to people about these displays 25 JCH says 5 Jun 2015 at 9 28 AM David Appell Land Ahoy 26 CM says 5 Jun 2015 at 10 06 AM My brain exploded halfway down Curry s post where the GWPF of all people criticize Karl et al for taking 1998 as a starting year Fodder for a follow up Lewandowski paper Recursive Seepage anyone 27 Doc Savage Fan says 5 Jun 2015 at 10 35 AM I m really struggling with this study as it essentially implies that the data from all the other various temperature datasets is not correct How can that be Response It might be less of a struggle if you actually read the second paragraph gavin 28 Chris Colose says 5 Jun 2015 at 10 42 AM Joe Duarte There s no implication for climate sensitivity here 29 Hank Roberts says 5 Jun 2015 at 11 47 AM David Appell says So what to make of the 20 years of zero trend http www remss com research climate The troposphere has not warmed as fast as almost all climate models predict Possible reasons include increased oceanic circulation leading to increased subduction of heat into the ocean higher than normal levels of stratospheric aerosols due to volcanoes during the past decade incorrect ozone levels used as input to the models lower than expected solar output during the last few years or poorly modeled cloud feedback effects It is possible or even likely that a combination of these candidate causes is responsible 30 Armando says 5 Jun 2015 at 11 48 AM Gavin You say that that volcanoes and the cooling associated with their emissions was underestimated post 2000 your p aper says the cooling of Pinatubo eruption was overestimated Did you study this effect before 1991 31 MarkR says 5 Jun 2015 at 4 27 PM Joe Duarte They could add 0 12 C to the buoy data or subtract 0 12 C from the ship data It doesn t change the final result Let s go to an imaginary planet where we pretend that ships always measure temperatures that re 0 3 C warmer than reality and buoys only measure 0 1 C warmer than reality Let s pretend that temperatures are 20 C and they stay the over a decade during which we measure The ships always record 20 3 C and the buoys always record 20 1 C We get rid of the constant bias in each type by looking at changes both of them report the true answer of 0 C change 20 3 20 3 0 C for the ships and 20 1 20 1 0 C for the buoys But what if we switched from using the ship measurements to using the buoys sometime in the middle We would go from the ship record of 20 3 C at the beginning to the buoy record of 20 1 C at the end inventing a non existent cooling of 0 2 C We need to use the difference in measurements between the ships buoys to correct We could either add 0 2 C to all of the buoy measurements and do 20 3 20 1 0 2 0 C Or take 0 2 C from the ships and do 20 3 0 2 20 1 0 C Either way the result is the same How can we get the bias differences There are various ways but in this case the group looked at all the cases where ship and buoy measurements were next to each other They should both be measuring the same real T but they will each report different measurements because of the instrument biases In the example above the ship will measure 20 3 C and the buoy 20 1 C so we know in this case the difference is 0 2 C In reality you take lots of measurements to remove random instrumental error etc Ultimately you end up with the required adjustment size and you should make this adjustment because it brings you closer to reality The consistency of the differences between buoys ships 0 12 C obs shows that the ship records appear to be quite stable and our temperature change estimates are good so long as we use this correction For the calculated global warming it doesn t matter if you apply the correction to the ships or to the buoys and the fact that ship intakes are warmer than the environment is irrelevant because of the bias correction and conversion to anomalies Cato forget to mention this 32 Eli Rabett says 5 Jun 2015 at 6 15 PM Armndo The 1988 GISS climate model included volcanic forcing as well as a prediction of what would happen in the future if a large tropical volcano went boom 33 Brian Dodge says 5 Jun 2015 at 6 44 PM I m really struggling with this study as it essentially implies that the data from all the other various temperature datasets is not correct How can that be I think you may be confusing correct with accurate All datasets are measurements All measurements have inaccuracies Consider for instance eggs There are 12 count them in a dozen there aren t 12 0 5 According to USDA standards a dozen large eggs weighs measure them a minimum of 24 ounces the next grade minimum is 27oz so the scientific description would be 24 3 0 oz That is a lot specification an individual egg in a dozen large eggs can weigh as little as 23 12 of an ounce but only 5 of the eggs per case can be lower weight A case is 30 dozen so that s 18 eggs The uneven spatial distribution many missing data points and a large number of non climatic biases varying in time and space all contribute inaccuracies to to the global temperature record as do errors in orbital decay corrections limb corrections diurnal corrections and hot target corrections all of which rely on measurements inherent errors in the satellite temperature records In addition since the global surface temperature records are a measure that responds to albedo changes volcanic aerosols cloud cover land use snow and ice cover solar output and differences in partition of various forcings into the oceans atmosphere land cryosphere teasing out just the effect of CO2 water vapor over the short term is difficult to impossible see https tamino wordpress com 2014 12 04 a pause or not a pause that is the question 34 Armando says 6 Jun 2015 at 1 58 AM Eli Rabbet That clears things up Before 1990 all the eruptions comparable with the post Pinatubo eruptions see Gavins paper of 2014 have been taken into account then 35 Buck Smith says 6 Jun 2015 at 8 05 AM The thing that looks fishy is that the adjustments all tend to make past colder present warmer and increase the trend That is nto necessarily worng But when you see that adjustment are underwieghting ARGO buoy for heated ship intake extending arctic land temps over the arctic ocean 36 Jim Baird says 6 Jun 2015 at 9 30 AM Dr Peter Stott commenting on Gavin s study in the Guardian http www theguardian com environment 2015 jun 04 global warming hasnt paused study finds says the term slowdown is valid because the past 15 years might have been still hotter were it not for natural variations like deep ocean heat uptake I have to agree with Mike 20 the need is for action based on the lessons learned from Nature s response to planetary heating i e converting some to mechanical energy in the form of storms and moving more to the planetary heat sinks of the poles and deeper water Moving the heat to the poles is clearly detrimental Moving it to the depths is an opportunity to replace all fossil fuels with heat pipe ocean thermal energy conversion http climatecolab org web guest plans plans contestId 1301414 planId 1315102 37 Eli Rabett says 6 Jun 2015 at 1 33 PM Armando To an extent see Brian Dodge above One of the most interesting mysteries are what appears to be large volcanic eruptions in the proxy records pre 1500 for which everybunny and their brother searches for the volcano It is an annual sport at AGU 38 Eli Rabett says 6 Jun 2015 at 1 35 PM Just found this Modified from Table 3 in Newhall CG and S Self 1982 The volcanic explosivity index VEI An estimate of explosive magnitude for historical volcanism Journal of Geophysical Research87 1231 1238 Additional eruptions added from tree ring data reported in Table 2 of Briffa KR PD Jones FH Schweingruber TJ Osborn 1998 Influence of volcanic eruptions on Northern hemisphere summer temperature over the past 600 years Nature 393 450 455 Note that other large eruptions occurred during the last 600 years according to tree ring and ice core data but are not indicated here because the source volcano is unknown e g 1809 39 Chris Colose says 6 Jun 2015 at 7 38 PM Eli I don t want to go too off topic but in recent years people have started to call the big 1258 eruption by name Samalas Forcing is complicated though because you need to know things like aerosol size distribution Even for Pinatubo there s some issues with saturation of the SAGE satellite sensor and the historic eruptions before that have even more uncertainty I think there s good

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  • Global warming and unforced variability: Clarifications on recent Duke study « RealClimate
    1993 to 2050 and then drew conclusions about 2002 to 2013 Unless I misunderstood the paper Could you clarify I ll add a link to the article I wrote at the time 9 Patrick Brown says 14 May 2015 at 7 48 AM Hi Sou I understand your confusion we could have been more explicit about the meaning of the calculation The idea was to attempt to quantify how likely various rates of forced warming might be given recent observed trends We used multi model mean rates of warming associated with the different emissions scenarios to represent 3 different forced rates of warming So for example the multi model mean rate of warming for the historical simulation RCP 8 5 from 1993 2050 was 0 03 C yr We then quantified how likely it might be that the forced rate of warming had been 0 03 C yr given that we had just seen an 11 year negative linear trend Therefore this comparison gives us information on the likelihood of the rate of forced warming 0 03 C yr over the recent past but it does not give us information on the likelihood of the RCP 8 5 progression in the future We simply labeled the 0 03 C yr forced rate of warming RCP 8 5 since 0 03 C yr approximates the characteristic rate of warming for RCP 8 5 at least through 2050 Instead of labeling it RCP 8 5 we could have labeled it 0 03 C yr forced warming or something similar 10 Sou says 15 May 2015 at 12 04 AM Patrick thanks for the reply Yes the different labeling would have made things clearer for me The other thing I noticed was that your trend calculations all used 2013 as an end point To what extent does the choice of 2013 as an end point to your calculations affect your results For example would 2014 or if 2015 ends up being still hotter make a large difference overall Or 2010 or 2005 11 Rob Ellison says 15 May 2015 at 1 39 AM There are three possible modes of climate change The traditional view of a gradual change with changes in climate forcing Periodic oscillation around an equilibrium climate state Abrupt climate shifts to a new mean and variance https watertechbyrie files wordpress com 2014 06 ghil sensitivity png The third is the reality and temperature is more or less the result of chaotic responses in the climate system The ubiquitous multi decadal oscillations are in this view chaotic climate shifts in a dynamically complex system at 20 to 30 year intervals with shifts in the state of the Pacific Ocean and in surface temperature The current cool Pacific Ocean state seems more likely than not to persist for 20 to 30 years from 2002 The flip side is that beyond the next decade or so the evolution of the global mean surface temperature may hold surprises on both the warm and cold ends of the spectrum The global climate system is composed of a number of subsystems atmosphere biosphere cryosphere hydrosphere and lithosphere each of which has distinct characteristic times from days and weeks to centuries and millennia Each subsystem moreover has its own internal variability all other things being constant over a fairly broad range of time scales These ranges overlap between one subsystem and another The interactions between the subsystems thus give rise to climate variability on all time scales Michael Ghil Complexity science suggests that small changes in control variables including greenhouse gases push the climate system past a threshold at which stage the balance between the components of the system shift abruptly into a new balance It is in the jargon known as unforced internal variability The US National Academy of Sciences NAS defined abrupt climate change as a new climate paradigm as long ago as 2002 A paradigm in the scientific sense is a theory that explains observations A new science paradigm is one that better explains data in this case climate data than the old theory Like the doyens of climate science who wrote Abrupt climate science inevitable surprises we can expect surprises that may in theory be faster and more extreme either cold or warm than a steady rise in global temperatures It does suggest that mitigation of greenhouse gases and of land use changes and aerosol emissions is prudent in an inherently unstable system One that has seen many major shifts in temperature and hydrology over the past 2 58 million years But it does make climate an intractable problem over the longer term As James McWilliams wrote sensitive dependence and structural instability are humbling twin properties for chaotic dynamical systems indicating limits about which kinds of questions are theoretically answerable On the other hand proponents of modes 1 and 2 from either side of the climate lines know no humility There is little in the way of complexity and nothing of uncertainty But if you do get past mode 2 and it took forever to get from mode 1 to mode 2 due warning there are a few questions that might come up How much of 20th century warming was natural and how much of that might we lose in the the 21st How might that be related to a 20th century millennial high in El Nino frequency and intensity How much can climate shift warm or cool in as little as a decade 12 Patrick Brown says 15 May 2015 at 8 15 AM Hi Sou 2013 wasn t really chosen as an endpoint 2013 was the most recent annual datapoint when the study was submitted so it was the natural endpoint to use The results of the study applied to past temperature progression so future data updates will not change the conclusions about the past For example no matter how warm 2015 ends up being there was still an 11 year negative linear trend from 2002 2013 and we can still quantify how likely various rates of forced warming were given that negative linear trend occurred Having said that I would like to keep this analysis up to date and I plan on re running the calculation for 2014 and 2015 2016 ect when the data comes in and publishing the results on my website 13 WebHubTelescope says 15 May 2015 at 12 21 PM Ellison ENSO contributes to the variability in global temperature but since ENSO reverts to a mean of zero it does not have any impact on the long term temperature trend This is not that hard to understand and I am not sure what your issue is 14 Barton Paul Levenson says 15 May 2015 at 7 06 PM PB 12 An 11 year sample won t tell you anything of significance You want at least 30 years for that 15 GlenFergus says 15 May 2015 at 7 47 PM It was a nice paper Patrick and well written after digesting the alphabet soup Figure 3 should be required viewing for pausers A challenge with the approach must be heteroscedasticity which you don t appear to mention is past unforced variation a guide to future unforced variation in a greatly perturbed climate system Or even is past unforced variation a good guide to recent unforced variation Probably it is but I doubt we re sure which may be what Rob Ellison is trying to say Also just looking at panels a and b one can lose sight of the scale Warming to date is pretty minor given what we face It does happen to fit a simplistic model with a constant increase in the rate of change a 3rd order polynomial which also happens to neatly extrapolate to the mid points of the RCP6 0 projections Higher order acceleration is required to get to RCP8 5 so it would be surprising if your approach found recent warming to be consistent with an RCP8 5 rate through 2050 http gergs net 2014 12 thoughts global temperature global monthly temps all long extrap 16 vukcevic says 16 May 2015 at 4 12 AM Natural variability what is it where does it come from Why it is different in the Atlantic from the Pacific Another look at the North Atlantic s SST trend lines could open a path to resolution of the enigma http www vukcevic talktalk net qAMO gif Ideas to the further understanding start HERE 17 Rob Ellison says 16 May 2015 at 5 12 PM The fact that around 1910 1940 and in the late 1970s climate shifted to a completely new state indicates that synchronization followed by an increase in coupling between the modes leads to the destruction of the synchronous state and the emergence of a new state http onlinelibrary wiley com wol1 doi 10 1029 2007GL030288 full The latest climate shift was in 1998 2001 and although changes in the intensity and frequency of ENSO is implicated in changes in global surface temperature it is a mistake to ignore resonant changes in the global climate system It involves shifts in the balance of atmosphere biosphere cryosphere hydrosphere and lithosphere physical mechanisms of unforced variability in a complex dynamical system The mechanism of unforced variability is dynamical complexity ENSO frequency and intensity varies oven decades to millennia The 1000 year peak in El Nino frequency last century https watertechbyrie files wordpress com 2014 06 vance2012 antartica law dome ice core salt content png http journals ametsoc org doi abs 10 1175 JCLI D 12 00003 1 journalCode clim Over the Holocene Moy et al 2002 present the record of sedimentation shown below which is strongly influenced by ENSO variability It is based on the presence of greater and less red sediment in a lake core More sedimentation is associated with El Niño It has continuous high resolution coverage over 11 000 years It shows periods of high and low ENSO activity alternating with a period of about 2 000 years There was a shift from La Niña dominance to El Niño dominance that was identified by Tsonis 2009 as a chaotic bifurcation and is associated with the drying of the Sahel There is a period around 3 500 years ago of high ENSO activity associated with the demise of the Minoan civilisation Tsonis et al 2010 Red intensity was in excess of 200 For comparison red intensity in 1997 98 was 99 It shows ENSO variability considerably in excess of that seen in the modern period https watertechbyrie files wordpress com 2014 06 tsonis 2009 figure 1 png Unforced variability over the much longer term than the instrumental record is the best guide to the potential for abrupt shift in climate This is not remotely 0 1 degrees C It is 16 degrees C in places in as little as a decade http www nap edu openbook php record id 10136 page 1 Complexity theory suggests that the system is pushed by greenhouse gas changes and warming as well as solar intensity and Earth orbital eccentricities past a threshold at which stage the components start to interact chaotically in multiple and changing negative and positive feedbacks as tremendous energies cascade through powerful subsystems Some of these changes have a regularity within broad limits and the planet responds with a broad regularity in changes of ice cloud Atlantic thermohaline circulation and ocean and atmospheric circulation The recurrent dynamics current cool Pacific Ocean state seems more likely than not to persist for 20 to 30 years from 2002 The flip side is that beyond the next few decades the evolution of the global mean surface temperature may hold surprises on both the warm and cold ends of the spectrum Swanson and Tsonis 2009 The criticism of the paper is that it takes a short view and is based on mode 2 see comment 11 The reality of unforced variability is mode 3 dynamical complexity and exploring the implications of this is the future of climate science 18 Rob Ellison says 16 May 2015 at 5 24 PM Or even is past unforced variation a good guide to recent unforced variation Probably it is but I doubt we re sure which may be what Rob Ellison is trying to say Past unforced variability is well outside the 0 1 degree C The scope of future climate shift timing and extent is not remotely predictable If we assume the system is ergodic then it may stay within the limits of the Quaternary 19 JCH says 17 May 2015 at 9 50 AM Well the cool phase of the Pacific obviously did not last 20 to 30 years Ellison your heroes married the wrong ocean cycle http www ospo noaa gov data sst anomaly 2015 anomnight 5 14 2015 gif 20 WebHubTelescope says 17 May 2015 at 10 52 AM Ellison There is no such thing as complexity theory apart from the sense of algorithmic complexity in the computational sciences ENSO does not arise because of any notions of complexity theory You continue to add FUD to the discussion by making all these pretentious statements that when it comes down to it are simply laughable 21 Rob Ellison says 17 May 2015 at 2 27 PM This study uses proxy climate records derived from paleoclimate data to investigate the long term behaviour of the Pacific Decadal Oscillation PDO and the El Niño Southern Oscillation ENSO During the past 400 years climate shifts associated with changes in the PDO are shown to have occurred with a similar frequency to those documented in the 20th Century Importantly phase changes in the PDO have a propensity to coincide with changes in the relative frequency of ENSO events where the positive phase of the PDO is associated with an enhanced frequency of El Niño events while the negative phase is shown to be more favourable for the development of La Niña events http onlinelibrary wiley com wol1 doi 10 1029 2005GL025052 full Blue is dominant I m not sure that putting a trend line to the PDO means anything at all We are looking at a tendency to increased upwelling in the north eastern Pacific this century There are 20 to 30 year regimes in the data and abrupt changes between http stateoftheocean osmc noaa gov atm images pdo long gif Similarly with ENSO Moderate and less frequent El Nino this century http www esrl noaa gov psd enso mei ts gif JCH shows the PDO trending down since 1980 The reality is that it was positive to 1998 and shifted negative in 1998 2001 He then shows a recent trend line up There is no suggestion that there are not periods of warm surface water in cool PDO and vice versa Just a tendency for enhanced upwelling in cool modes It is certainly too early too tell whether the PDO has shifted again What is important however is the underlying dynamical mechanism of abrupt climate change in the globally resonant system JCH should take a long view based based on mode 3 comment 11 thinking 22 vukcevic says 17 May 2015 at 4 42 PM 19 20 21 Pacific ocean floor is a thin membrane oscillating under influence of the magma pressure points tectonics with its multidecadal oscillations directly reflected in the SOI southern oscillation index http www vukcevic talktalk net P SC gif 23 Hank Roberts says 17 May 2015 at 10 25 PM http climdyn usc edu Publications files skewness rev v2 pdf This stuff isn t news It s interesting as science 24 Hank Roberts says 18 May 2015 at 9 55 AM the underlying dynamical mechanism of abrupt climate change in the globally resonant system Do these words mean anything I d ask for a cite but I ve watched this dance play out on many blogs over several years If you d got something publishable somewhere written up why would you keep flogblogging the basic message which appears to be we don t know we can t know and we shouldn t spend any money to stop burning fossil carbon I think that sums up the message eh 25 chris korda says 22 May 2015 at 2 16 PM Given that the RCPs have barely begun to diverge as this graph clearly shows would someone please explain the significance of the finding Isn t it a bit premature to judge that recently observed GMT values as well as trends are near the lower bounds of the EUN for a forced signal corresponding to the RCP 8 5 emissions scenario We ll be in a much better position to judge that in 2030 Of course by then we ll be toast regardless of whether it s 8 5 or 6 0 Guess we should act as if we re on RCP 8 5 just in case I ask because several commenters here have opined in the fairly recent past that RCP 8 5 is reality and the rest mere wishful thinking 26 steven says 23 May 2015 at 4 34 PM Why do you say confusion From ppl and websites like that it is not confusion it is outright lies If its a fear of legal issues well I suppose OK but not calling them out just helps their case IMHO 27 Aaron says 25 May 2015 at 3 14 PM Consider a planet with an atmosphere and an ice cap over a liquid ocean Suppose natural variability causes the ice cap to vary in thickness from 20 m to 2 m on a time frame of 100k years This causes only a small signal in the air temperature because the air is always in contact with ice Suppose then changes in the atmosphere cause warming such that a meter of ice melts on a time frame of 50 years If this occurs when the ice is thick heat from the air is transferred to the ice and there is very little signal of warming in the air as

    Original URL path: http://www.realclimate.org/index.php/archives/2015/05/global-warming-and-unforced-variability-clarifications-on-recent-duke-study/ (2016-02-13)
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  • Climate modelling « RealClimate
    Hypothesis A Negative or Positive Cloud Feedback Journal of Climate vol 15 pp 3 7 2002 2 0 CO 2 http dx doi org 10 1175 1520 0442 2002 015 2 0 CO 2 B Lin T Wong B A Wielicki and Y Hu Examination of the Decadal Tropical Mean ERBS Nonscanner Radiation Data for the Iris Hypothesis Journal of Climate vol 17 pp 1239 1246 2004 2 0 CO 2 http dx doi org 10 1175 1520 0442 2004 017 2 0 CO 2 H Su J H Jiang Y Gu J D Neelin B H Kahn D Feldman Y L Yung J W Waters N J Livesey M L Santee and W G Read Variations of tropical upper tropospheric clouds with sea surface temperature and implications for radiative effects J Geophys Res vol 113 2008 http dx doi org 10 1029 2007JD009624 T Mauritsen and B Stevens Missing iris effect as a possible cause of muted hydrological change and high climate sensitivity in models Nature Geoscience vol 8 pp 346 351 2015 http dx doi org 10 1038 ngeo2414 A E Dessler Observations of Climate Feedbacks over 2000 10 and Comparisons to Climate Models Journal of Climate vol 26 pp 333 342 2013 http dx doi org 10 1175 jcli d 11 00640 1 Comments pop up 33 Reflections on Ringberg Filed under Aerosols Climate modelling Climate Science Greenhouse gases Instrumental Record IPCC Oceans Paleoclimate gavin 1 April 2015 As previewed last weekend I spent most of last week at a workshop on Climate Sensitivity hosted by the Max Planck Institute at Schloss Ringberg It was undoubtedly one of the better workshops I ve attended it was focussed deep and with much new information to digest some feel for the discussion can be seen from the ringberg15 tweets I ll give a brief overview of my impressions below More Comments pop up 83 Climate Sensitivity Week Filed under Aerosols Climate modelling Climate Science Greenhouse gases Instrumental Record IPCC Paleoclimate statistics gavin 22 March 2015 Some of you will be aware that there is a workshop on Climate Sensitivity this week at Schloss Ringberg in southern Germany The topics to be covered include how sensitivity is defined and whether it is even meaningful Spoiler yes it is what it means how it can be constrained what the different flavours signify etc There is an impressive list of attendees with a very diverse range of views on just about everything and so I am looking forward to very stimulating discussions More Comments pop up 26 The Soon fallacy Filed under Climate modelling Climate Science Sun earth connections gavin 24 February 2015 As many will have read there were a number of press reports NYT Guardian InsideClimate about the non disclosure of Willie Soon s corporate funding from Southern Company an energy utility Koch Industries etc when publishing results in journals that require such disclosures There are certainly some interesting questions to be asked by the OIG about adherence to the

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  • Climate modelling « RealClimate
    K Folland G R Harris and J M Murphy Improved Surface Temperature Prediction for the Coming Decade from a Global Climate Model Science vol 317 pp 796 799 2007 http dx doi org 10 1126 science 1139540 N S Keenlyside M Latif J Jungclaus L Kornblueh and E Roeckner Advancing decadal scale climate prediction in the North Atlantic sector Nature vol 453 pp 84 88 2008 http dx doi org 10 1038 nature06921 Comments pop up 45 NOAA temperature record updates and the hiatus Filed under Climate modelling Climate Science Instrumental Record gavin 4 June 2015 In a new paper in Science Express Karl et al describe the impacts of two significant updates to the NOAA NCEI née NCDC global temperature series The two updates are 1 the adoption of ERSST v4 for the ocean temperatures incorporating a number of corrections for biases for different methods and 2 the use of the larger International Surface Temperature Initiative ISTI weather station database instead of GHCN This kind of update happens all the time as datasets expand through data recovery efforts and increasing digitization and as biases in the raw measurements are better understood However this update is going to be bigger news than normal because of the claim that the hiatus is no more To understand why this is perhaps less dramatic than it might seem it s worth stepping back to see a little context More References T R Karl A Arguez B Huang J H Lawrimore J R McMahon M J Menne T C Peterson R S Vose and H Zhang Possible artifacts of data biases in the recent global surface warming hiatus Science vol 348 pp 1469 1472 2015 http dx doi org 10 1126 science aaa5632 B Huang V F Banzon E Freeman J Lawrimore W Liu T C Peterson T M Smith P W Thorne S D Woodruff and H Zhang Extended Reconstructed Sea Surface Temperature Version 4 ERSST v4 Part I Upgrades and Intercomparisons Journal of Climate vol 28 pp 911 930 2015 http dx doi org 10 1175 JCLI D 14 00006 1 Comments pop up 85 Global warming and unforced variability Clarifications on recent Duke study Filed under Climate modelling Climate Science Instrumental Record IPCC group 13 May 2015 Guest Commentary from Patrick Brown and Wenhong Li Duke University We recently published a study in Scientific Reports titled Comparing the model simulated global warming signal to observations using empirical estimates of unforced noise Our study seemed to generated a lot of interest and we have received many inquires regarding its findings We were pleased with some of coverage of our study e g here but we were disappointed that some outlets published particularly misleading articles e g here here and here Since there appears to be some confusion regarding our study s findings we would like to clarify some points see also MM4A s discussion More References P T Brown W Li E C Cordero and S A Mauget Comparing the model simulated

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  • How do trees change the climate? « RealClimate
    vines and ground covers all of which can provide food and materials as well as benefit each other are even better at preserving soil moisture while also encouraging diverse wildlife and providing high yields of multiple food crops lumber and other materials Forest cover helps preserve and even out rainfall and moisture over a large area and decreases both droughts and floods which can mutually reinforce each other to bad effect Both cause plant cover to decrease which causes soil moisture decreases often making storms less frequent less regular less predictable and more intense further decreasing plant cover reducing or killing crops eroding soil leading to decreased fertility water pollution etc and spiraling down into desertification and the creation of wasteland from what had been a fertile verdant landscape In hot climates trees reduce local temperatures providing cool refuge decreasing violence and reducing air conditioning costs and GHG emissions while providing food lumber vertical playgrounds etc In colder climates deciduous trees can do the same while allowing winter sunlight in reducing heating costs and emissions Trees provide green a psychologically beneficial background and what I call flock movement of leaves movement that is complexly even wickedly coordinated but non regimented non identical Symphonic movement one might say This is a psycho physiologically significant alternative to sterile walls and the movements humans tend to create through machinery and as is becoming more clear see works on Nature Deficit Disorder for example is crucial to human development and psychological health Diverse prairie systems also provide this as well as bird movements and other natural phenomenon but trees and forests the natural habitat where most humans live are unparalleled in this regard http www usgs gov newsroom article asp ID 3781 VE6c5md0zb0 see Toby Hemenway Gaia s Garden A Guide to Home Scale Permaculture or especially the mind blowing 2 volume Edible Forest Gardens by Dave Jacke and Eric Toensmeier as well as Bill Mollison s Introduction to Permaculture and Permaculture A Designer s Manual http cdp sagepub com content 10 1 33 abstract and many other studies confirm this http scholar google com scholar q nature deficit disorder hl en as sdt 0 as vis 1 oi scholart sa X ei MKhOVN6fB LhsASy0oKgDQ ved 0CB0QgQMwAA Also see Paul Shepard Nature and Madness 12 Eli Rabett says 27 Oct 2014 at 9 08 PM Thanks 13 Emanuele Lombardi says 27 Oct 2014 at 10 51 PM One thing that seems to be overlooked completely here Trees do not simply absorb energy and get warmer The albedo effect is more relevant with inorganic surfaces that living matter The solar energy is used to combine H2O and CO2 into hydrocarbons an endothermic reaction thus storing large amount of energy that can released later by burning the wood for example It seems to me that young trees grow more quickly that older trees thereby absorbing more energy per plant Exactly the opposite that is stated in the article A 3 to 5 year planting cycle is much more efficient than waiting for the 20 years suggested The plants could be used to make paper and cardboard for much more Eco friendly packing material than current plastic products E Lombardi 14 Abby Swann says 28 Oct 2014 at 1 03 AM Re John Mashey Check out this paper on the climate impacts of bark beetles in Canada H Maness P Kushner and I Fung Summertime climate response to mountain pine beetle disturbance in british columbia Nature Geoscience 6 1 65 70 2012 http www nature com ngeo journal v6 n1 full ngeo1642 html 15 Russell says 28 Oct 2014 at 2 50 AM The central question at issue is the magnitude of the albedo forcing from changes in human land use The impact of tree planting in previously unforested areas can be paradoxical as it depends both on seasonal changes in surface albedo eg from snowfall and sun angle a and shadow area effects In circunstances where these factors combine planting trees as carbon offsets above the lcal tree line at high latitudes modeling indicates that the radiative forcing impact can outwigh the benefits of carbon sequestration cf Bala et al Combined climate and carbon cycle effects of large scale deforestation Proc Natl Acad Sci 104 6550 6555 2007 16 Mack says 28 Oct 2014 at 4 52 AM Maybe planting trees is meaningless Seems that the lungs of the world is not the Amazon forests after all but the oceans Oh dear how sad there there never mind https www youtube com watch v OSRgKKoLLiQ 17 Bart Declercq says 28 Oct 2014 at 7 18 AM 13 E Lombardi you state it seems to me young trees grow more quickly than older trees this is only true proportionally in absolute terms an older tree grows more quickly a 20 increase in a small tree weighing 100kg 20kg of additional mass a 5 increase in a 1 tonne tree slower growth 50kg of additional mass So the bigger tree will be absorbing more energy in the absolute even if its proportional growth is less You might argue that you can plan 3 small trees in the space needed by the bigger tree and the advantage tilts back to the smaller tree but one would need to measure and test this before making such a statement for example an old large tree could easily weigh 100 tonnes grow at 2 2000kg per year yet take up less space than the 100 small trees required to store the same amount of mass 18 Hank Roberts says 28 Oct 2014 at 7 33 AM Caldeira s 2007 discussion which Dr Unger cites in her linked summary of support for her piece is quite clear http www nytimes com 2007 01 16 opinion 16caldeira html Those who haven t read that are missing the points that need to be understood 19 Hank Roberts says 28 Oct 2014 at 7 55 AM Also 20 Kevin McKinney says 28 Oct 2014 at 9 06 AM Big trees vs smaller http www nature com nature journal v507 n7490 full nature12914 html 21 Hank Roberts says 28 Oct 2014 at 9 50 AM It seems to me that young trees grow more quickly than older trees Everyone has an opinion facts are harder to come by and site specific Scholar can be helpful if you d like facts 22 Hank Roberts says 28 Oct 2014 at 9 52 AM Thank you Kevin McKinney I m reposting your link to catch the attention of those who won t bother to click on it Rate of tree carbon accumulation increases continuously with tree size Nature 507 90 93 06 March 2014 doi 10 1038 nature12914 Editor s summary Old forests and their leaves fix less carbon than do new forests but does this apply at the individual tree level This study uses a global analysis of more that 400 tree species to show that it does not Rather larger and older trees accumulate carbon more rapidly than do younger smaller ones This can be reconciled with the effects at other levels by taking into account increases in leaf number and reductions in forest density with age The rapid growth of large trees means that relative to their numbers they could have a disproportionately important role in forest feedbacks to the terrestrial carbon cycle and global climate system 23 Abby Swann says 28 Oct 2014 at 11 22 AM Re Hank Roberts about Ken Caldeira s 2007 opinion piece The Caldeira piece is consistent with the science I lay out above Caldeira says preservation and restoration of forests outside the tropics will do little or nothing to help slow climate change emphasis mine and In contrast tropical forests appear to be doubly valuable to the earth s climate system Not only do they store copious amounts of carbon the roots of tropical trees reach down deep drawing up water that they evaporate through their leaves So I concur with Caldeira trees in mid and high latitudes have uncertain or warming effects on climate but trees in the tropics keep things cool 24 Jim Bullis says 28 Oct 2014 at 11 55 AM This all leaves me scratching my head in disbelief In the rush to punish coal with actions that have debilitating effects on our economy some effort to find alternative actions seemed worthwhile The chemical composition of wood fiber including roots and the entire vegetative mass is roughly the same ton for ton as coal from the Powder River Basin I made that point here In that context I found and reported here that China was asserting in their State of the Nation report that they were acting to combat CO2 by planting forests This was in conjunction with their massive water projects This all went to my not well received suggestion that we take constructive action to create standing forests in the vast areas of under used land in the USA preferably on a whole North American continental basis This would involve a large scale water project modeled after the California Aquaduct system Yes that would be costly but it could easily be paid for out of agricultural proceeds that could be an associated benefit of general irrigation We could actually do even more if we actually established a universal irrigation project on a scope much less than our national highway system Then I find that there are famous persons going about proclaiming a huge water shortage My answer to that is that there is only a water distribution problem that we know well how to solve as did the Romans and the Babylonians some time ago And then I discovered the great Dam removal project terrorist acts Ah yes as shown on youtube and for example the Carmel Valley absurd actions on behalf of some salmon Salmon need help but lets get a grip Oh well it seems there is huge enthusiasm for bashing coal and making salmon happy but not much for serious constructive action And now we have an assertion that the CO2 effect of trees is approximately balanced between photosynthesis and aspiration Huh If we assume that trees are all burned down eventually maybe so It is not balanced if the trees stand and forest products are long preserved If there is a massive aggregate of standing vegetative mass that was not there before then there could be a serious mechanism for capturing and storing CO2 25 Roger A Pielke Sr says 28 Oct 2014 at 3 06 PM Here are two more papers on this subject that you might find useful McAlpine C A J G Ryan L Seabrook S Thomas P J Dargusch J I Syktus R A Pielke Sr A E Etter P M Fearnside and W F Laurance 2010 More than CO2 A broader picture for managing climate change and variability to avoid ecosystem collapse Current Opinion in Environmental Sustainability 2 334 336 DOI10 1016 j cosust 2010 10 001 http pielkeclimatesci wordpress com files 2010 12 r 355 pdf Marland G R A Pielke Sr M Apps R Avissar R A Betts K J Davis P C Frumhoff S T Jackson L Joyce P Kauppi J Katzenberger K G MacDicken R Neilson J O Niles D dutta S Niyogi R J Norby N Pena N Sampson and Y Xue 2003 The climatic impacts of land surface change and carbon management and the implications for climate change mitigation policy Climate Policy 3 149 157 http pielkeclimatesci wordpress com files 2009 10 r 267 pdf The abstract of the second paper reads Strategies to mitigate anthropogenic climate change recognize that carbon sequestration in the terrestrial biosphere can reduce the build up of carbon dioxide in the Earth s atmosphere However climate mitigation policies do not generally incorporate the effects of these changes in the land surface on the surface albedo the fluxes of sensible and latent heat to the atmosphere and the distribution of energy within the climate system Changes in these components of the surface energy budget can affect the local regional and global climate Given the goal of mitigating climate change it is important to consider all of the effects of changes in terrestrial vegetation and to work toward a better understanding of the full climate system Acknowledging the importance of land surface change as a component of climate change makes it more challenging to create a system of credits and debits wherein emission or sequestration of carbon in the biosphere is equated with emission of carbon from fossil fuels Recognition of the complexity of human caused changes in climate does not however weaken the importance of actions that would seek to minimize our disturbance of the Earth s environmental system and that would reduce societal and ecological vulnerability to environmental change and variability The importance of land use land cover change in the context of policy responses to the human involvement in the climate system has not been adequately recognized in the IPCC and other climate assessments Roger Sr 26 SecularAnimist says 28 Oct 2014 at 4 28 PM Jim Bullis wrote In the rush to punish coal with actions that have debilitating effects on our economy Nonsense First there is no such rush to punish coal Second even the fastest possible phase out of ALL coal use would have NO debilitating effects on our economy and would in fact have enormous economic BENEFITS even apart from reducing carbon pollution 27 Michael Hauber says 28 Oct 2014 at 4 29 PM What impact do trees have on wet bulb temperature The issue being that at a wet bulb temperature of 35 degrees C it is impossible to keep a human from dieing from heat by evaporation wind or shade As the wet bulb temperature is effectively the lowest possible temperature that evaporative cooling can reach I would guess that the evaporative cooling effect of trees would have no impact on wet bulb temperature but simply cash in some of the maximum possible evaporative cooling potential If so that would leave the albedo effect to push the wet bulb temperature up and the carbon storage effect to provide long term cooling The impact on wet bulb temperature may not be so relevant now with nowhere on earth close to the 35 degree limit But worst case scenarios suggest this limit may be reached by the end of the century 28 Radge Havers says 29 Oct 2014 at 9 44 AM Effects of Climate Variability and Accelerated Forest Thinning on Watershed Scale Runoff in Southwestern USA Ponderosa Pine Forests Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide http www plosone org article info 3Adoi 2F10 1371 2Fjournal pone 0111092 Setting priorities Effects of thinning on climate minimal negative or beneficial in this context Comments 29 Kevin Mckinney says 29 Oct 2014 at 11 11 AM De nada Hank and thanks for quoting Of course it is only one study and it presents a somewhat surprising result but it looks to my amateur eye as if they did a pretty substantial analysis I d think the result ought to receive some weight provisionally at least 30 Jim Bullis says 29 Oct 2014 at 12 09 PM RE 26 by Secular If you have been following the actions and planned actions of the EPA which seem to be putting unreasonable demands on new coal plants you might not make the same pronouncement You might also ask a power company though some tend to be more PR oriented and might not be truthful in the face of pandering to the local utility commission This is not to say that true pollution that actually damages air quality should not be seriously suppressed Practical systems that would reduce the use of coal are desirable But the responsibility for CO2 should not be as heavily carried by low cost coal power plants As to the economic BENEFITS you assert I suggest the opposite As I see it low cost electric power is key to our industrial economy which you might have noticed is not doing so well these days Yes that is hard to measure but quite frequently it seems those who plan expansions say that planning is hard in the present regulatory environment 31 Jim Eaton says 29 Oct 2014 at 1 54 PM The obvious move is to protect all old growth forests for their carbon sequestration and resistance to wildfires especially as climate change is increasing drought conditions in some large areas of forests A major problem with extensive plantings of young trees is their susceptibility to fire especially those planted as monocultures in rows for future logging operations Even plantings after salvage logging in a burned area often burn the hottest Reburn severity in managed and unmanaged vegetation in a large wildfire Jonathan R Thompson Thomas A Spies and Lisa M Ganio PNAS June 19 2007 http www pnas org content 104 25 10743 full In addition at least in coniferous forests by far the most successful replantings are from tree stock genetically adapted to a particular area This requires collection of seed from a diverse cross section of the forest before it was burned or logged And the idea of re plumbing North America to create forests in under used land is ludicrous There are reasons forests don t flourish in the lowlands of the Great Basin Mojave Desert or Great Plains and the absence of water is not it It would be far easier to reestablish the vast hardwood forests of the eastern half of the United States that existed before their conversion by European settlers And water diversions would not be needed 32 SecularAnimist says 29 Oct 2014 at 2 53 PM Jim Bullis wrote the actions and planned actions of the EPA which seem to be putting unreasonable demands on new coal plants I

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  • How do trees change the climate? « RealClimate
    world is not the Amazon forests after all but the oceans Oh dear how sad there there never mind https www youtube com watch v OSRgKKoLLiQ 17 Bart Declercq says 28 Oct 2014 at 7 18 AM 13 E Lombardi you state it seems to me young trees grow more quickly than older trees this is only true proportionally in absolute terms an older tree grows more quickly a 20 increase in a small tree weighing 100kg 20kg of additional mass a 5 increase in a 1 tonne tree slower growth 50kg of additional mass So the bigger tree will be absorbing more energy in the absolute even if its proportional growth is less You might argue that you can plan 3 small trees in the space needed by the bigger tree and the advantage tilts back to the smaller tree but one would need to measure and test this before making such a statement for example an old large tree could easily weigh 100 tonnes grow at 2 2000kg per year yet take up less space than the 100 small trees required to store the same amount of mass 18 Hank Roberts says 28 Oct 2014 at 7 33 AM Caldeira s 2007 discussion which Dr Unger cites in her linked summary of support for her piece is quite clear http www nytimes com 2007 01 16 opinion 16caldeira html Those who haven t read that are missing the points that need to be understood 19 Hank Roberts says 28 Oct 2014 at 7 55 AM Also 20 Kevin McKinney says 28 Oct 2014 at 9 06 AM Big trees vs smaller http www nature com nature journal v507 n7490 full nature12914 html 21 Hank Roberts says 28 Oct 2014 at 9 50 AM It seems to me that young trees grow more quickly than older trees Everyone has an opinion facts are harder to come by and site specific Scholar can be helpful if you d like facts 22 Hank Roberts says 28 Oct 2014 at 9 52 AM Thank you Kevin McKinney I m reposting your link to catch the attention of those who won t bother to click on it Rate of tree carbon accumulation increases continuously with tree size Nature 507 90 93 06 March 2014 doi 10 1038 nature12914 Editor s summary Old forests and their leaves fix less carbon than do new forests but does this apply at the individual tree level This study uses a global analysis of more that 400 tree species to show that it does not Rather larger and older trees accumulate carbon more rapidly than do younger smaller ones This can be reconciled with the effects at other levels by taking into account increases in leaf number and reductions in forest density with age The rapid growth of large trees means that relative to their numbers they could have a disproportionately important role in forest feedbacks to the terrestrial carbon cycle and global climate system 23 Abby Swann says 28 Oct 2014 at 11 22 AM Re Hank Roberts about Ken Caldeira s 2007 opinion piece The Caldeira piece is consistent with the science I lay out above Caldeira says preservation and restoration of forests outside the tropics will do little or nothing to help slow climate change emphasis mine and In contrast tropical forests appear to be doubly valuable to the earth s climate system Not only do they store copious amounts of carbon the roots of tropical trees reach down deep drawing up water that they evaporate through their leaves So I concur with Caldeira trees in mid and high latitudes have uncertain or warming effects on climate but trees in the tropics keep things cool 24 Jim Bullis says 28 Oct 2014 at 11 55 AM This all leaves me scratching my head in disbelief In the rush to punish coal with actions that have debilitating effects on our economy some effort to find alternative actions seemed worthwhile The chemical composition of wood fiber including roots and the entire vegetative mass is roughly the same ton for ton as coal from the Powder River Basin I made that point here In that context I found and reported here that China was asserting in their State of the Nation report that they were acting to combat CO2 by planting forests This was in conjunction with their massive water projects This all went to my not well received suggestion that we take constructive action to create standing forests in the vast areas of under used land in the USA preferably on a whole North American continental basis This would involve a large scale water project modeled after the California Aquaduct system Yes that would be costly but it could easily be paid for out of agricultural proceeds that could be an associated benefit of general irrigation We could actually do even more if we actually established a universal irrigation project on a scope much less than our national highway system Then I find that there are famous persons going about proclaiming a huge water shortage My answer to that is that there is only a water distribution problem that we know well how to solve as did the Romans and the Babylonians some time ago And then I discovered the great Dam removal project terrorist acts Ah yes as shown on youtube and for example the Carmel Valley absurd actions on behalf of some salmon Salmon need help but lets get a grip Oh well it seems there is huge enthusiasm for bashing coal and making salmon happy but not much for serious constructive action And now we have an assertion that the CO2 effect of trees is approximately balanced between photosynthesis and aspiration Huh If we assume that trees are all burned down eventually maybe so It is not balanced if the trees stand and forest products are long preserved If there is a massive aggregate of standing vegetative mass that was not there before then there could be a serious mechanism for capturing and storing CO2 25 Roger A Pielke Sr says 28 Oct 2014 at 3 06 PM Here are two more papers on this subject that you might find useful McAlpine C A J G Ryan L Seabrook S Thomas P J Dargusch J I Syktus R A Pielke Sr A E Etter P M Fearnside and W F Laurance 2010 More than CO2 A broader picture for managing climate change and variability to avoid ecosystem collapse Current Opinion in Environmental Sustainability 2 334 336 DOI10 1016 j cosust 2010 10 001 http pielkeclimatesci wordpress com files 2010 12 r 355 pdf Marland G R A Pielke Sr M Apps R Avissar R A Betts K J Davis P C Frumhoff S T Jackson L Joyce P Kauppi J Katzenberger K G MacDicken R Neilson J O Niles D dutta S Niyogi R J Norby N Pena N Sampson and Y Xue 2003 The climatic impacts of land surface change and carbon management and the implications for climate change mitigation policy Climate Policy 3 149 157 http pielkeclimatesci wordpress com files 2009 10 r 267 pdf The abstract of the second paper reads Strategies to mitigate anthropogenic climate change recognize that carbon sequestration in the terrestrial biosphere can reduce the build up of carbon dioxide in the Earth s atmosphere However climate mitigation policies do not generally incorporate the effects of these changes in the land surface on the surface albedo the fluxes of sensible and latent heat to the atmosphere and the distribution of energy within the climate system Changes in these components of the surface energy budget can affect the local regional and global climate Given the goal of mitigating climate change it is important to consider all of the effects of changes in terrestrial vegetation and to work toward a better understanding of the full climate system Acknowledging the importance of land surface change as a component of climate change makes it more challenging to create a system of credits and debits wherein emission or sequestration of carbon in the biosphere is equated with emission of carbon from fossil fuels Recognition of the complexity of human caused changes in climate does not however weaken the importance of actions that would seek to minimize our disturbance of the Earth s environmental system and that would reduce societal and ecological vulnerability to environmental change and variability The importance of land use land cover change in the context of policy responses to the human involvement in the climate system has not been adequately recognized in the IPCC and other climate assessments Roger Sr 26 SecularAnimist says 28 Oct 2014 at 4 28 PM Jim Bullis wrote In the rush to punish coal with actions that have debilitating effects on our economy Nonsense First there is no such rush to punish coal Second even the fastest possible phase out of ALL coal use would have NO debilitating effects on our economy and would in fact have enormous economic BENEFITS even apart from reducing carbon pollution 27 Michael Hauber says 28 Oct 2014 at 4 29 PM What impact do trees have on wet bulb temperature The issue being that at a wet bulb temperature of 35 degrees C it is impossible to keep a human from dieing from heat by evaporation wind or shade As the wet bulb temperature is effectively the lowest possible temperature that evaporative cooling can reach I would guess that the evaporative cooling effect of trees would have no impact on wet bulb temperature but simply cash in some of the maximum possible evaporative cooling potential If so that would leave the albedo effect to push the wet bulb temperature up and the carbon storage effect to provide long term cooling The impact on wet bulb temperature may not be so relevant now with nowhere on earth close to the 35 degree limit But worst case scenarios suggest this limit may be reached by the end of the century 28 Radge Havers says 29 Oct 2014 at 9 44 AM Effects of Climate Variability and Accelerated Forest Thinning on Watershed Scale Runoff in Southwestern USA Ponderosa Pine Forests Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide http www plosone org article info 3Adoi 2F10 1371 2Fjournal pone 0111092 Setting priorities Effects of thinning on climate minimal negative or beneficial in this context Comments 29 Kevin Mckinney says 29 Oct 2014 at 11 11 AM De nada Hank and thanks for quoting Of course it is only one study and it presents a somewhat surprising result but it looks to my amateur eye as if they did a pretty substantial analysis I d think the result ought to receive some weight provisionally at least 30 Jim Bullis says 29 Oct 2014 at 12 09 PM RE 26 by Secular If you have been following the actions and planned actions of the EPA which seem to be putting unreasonable demands on new coal plants you might not make the same pronouncement You might also ask a power company though some tend to be more PR oriented and might not be truthful in the face of pandering to the local utility commission This is not to say that true pollution that actually damages air quality should not be seriously suppressed Practical systems that would reduce the use of coal are desirable But the responsibility for CO2 should not be as heavily carried by low cost coal power plants As to the economic BENEFITS you assert I suggest the opposite As I see it low cost electric power is key to our industrial economy which you might have noticed is not doing so well these days Yes that is hard to measure but quite frequently it seems those who plan expansions say that planning is hard in the present regulatory environment 31 Jim Eaton says 29 Oct 2014 at 1 54 PM The obvious move is to protect all old growth forests for their carbon sequestration and resistance to wildfires especially as climate change is increasing drought conditions in some large areas of forests A major problem with extensive plantings of young trees is their susceptibility to fire especially those planted as monocultures in rows for future logging operations Even plantings after salvage logging in a burned area often burn the hottest Reburn severity in managed and unmanaged vegetation in a large wildfire Jonathan R Thompson Thomas A Spies and Lisa M Ganio PNAS June 19 2007 http www pnas org content 104 25 10743 full In addition at least in coniferous forests by far the most successful replantings are from tree stock genetically adapted to a particular area This requires collection of seed from a diverse cross section of the forest before it was burned or logged And the idea of re plumbing North America to create forests in under used land is ludicrous There are reasons forests don t flourish in the lowlands of the Great Basin Mojave Desert or Great Plains and the absence of water is not it It would be far easier to reestablish the vast hardwood forests of the eastern half of the United States that existed before their conversion by European settlers And water diversions would not be needed 32 SecularAnimist says 29 Oct 2014 at 2 53 PM Jim Bullis wrote the actions and planned actions of the EPA which seem to be putting unreasonable demands on new coal plants I have been following the EPA s proposed power plant emission regulations very closely and there is nothing remotely unreasonable about the proposed regulations for new coal fired power plants I note that you have not provided any specifics as to what you consider unreasonable Indeed given the severity and urgency of the global warming problem an immediate outright ban on new coal fired power plants would not be unreasonable Jim Bullis wrote low cost electric power is key to our industrial economy I agree electricity is the life blood of modern civilization However natural gas and wind are both already cheaper than new coal fired power plants even without the new EPA regulations Electricity from distributed solar photovoltaics is projected by the CEO of Duke Energy one of America s largest utilities to cost less than the retail price of grid power in 25 states within a couple of years And when the full costs of coal are taken into account there is nothing remotely cheap about coal Jim Bullis wrote the responsibility for CO2 should not be as heavily carried by low cost coal power plants As noted above coal is not low cost As for the responsibility for CO2 according to the EPA coal combustion represents about 39 percent of electricity generated in the USA but accounts for 75 percent of the CO2 emissions from electricity generation which accounts for 32 percent of total US emissions Moreover according to the US Energy Information Administration CO2 emissions from coal increased more than 4 percent from 2012 to 2013 and were up almost 12 percent in January February 2014 from January February 2013 In short coal fired electricity generation produces a grossly disproportionate and increasing part of the USA s total emissions relative to any benefits and as such it is completely logical to target coal for rapid steep emission reductions We already have better and cheaper ways to produce plenty of electricity 33 Magnus W says 29 Oct 2014 at 4 29 PM One argument for planting trees up north in Sweden has been that it might increase wood as building material instead of concrete and that would lower co2 emissions any one tried to make that point in this debate 34 John Mashey says 29 Oct 2014 at 5 08 PM re 14 on bark beetles Thanks Abby We ski in B C every year and can see the beetle damage when we fly over to Kelowna but it s nice to see the climate effects quantified 35 Russell says 29 Oct 2014 at 8 18 PM John how much of a carbon credit do I get for not heli skiing 36 John Mashey says 30 Oct 2014 at 12 31 AM Magnus try http www economist com blogs babbage 2014 04 wooden skyscrapers March 22nd saw the topping out ceremony of the tallest contemporary wood building in the world and the first that might be considered a true skyscraper the 30m Wood Innovation and Design Centre pictured in Prince George British Columbia Its designer Michael Green says Frankly we aren t breaking a sweat It s only public perception and emotion trumping science that stalls us moving higher He hopes to start work on a 20 storey vertical food farm in Vancouver later this year 37 mitch says 1 Nov 2014 at 11 14 AM Jim Bullis who wrote But the responsibility for CO2 should not be as heavily carried by low cost coal power plants You should be aware that back in the 70 s coal power plants were exempted from many of the pollution regulations grandfathered with the idea that these plans would be replaced over the next 40 years Instead many operators upgraded the plants so that they could keep the exemption and would not have to deal with clean air regulations Many of these are the low cost coal plants of today They made a business decision assuming that they could continue to externalize the cost of cleaning up They ve had around 40 years to clean up their act so I cannot feel sympathetic that they didn t use the time to actually try to comply with the spirit of the law 38 JustinWonder says 1 Nov 2014 at 12 41 PM Great article a joy to read 39 Matthew R Marler says 1 Nov 2014 at 1 29 PM That was a good short

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  • 2015 Temperatures « RealClimate
    this up with the RATPAC A data set here it agrees exactly Can I conclude from this that RATPAC was indeed the radiosonde data that is referenced here Or were other data sets averaged in with the RATPAC data It s interesting to see that the surface data for 2015 shows a whopping 0 28C increase over the previous year but I presume this is biased more to NH land data Is that correct Also if I look at the 800 350 mb data here then 2015 is clearly the warmest year for the Globe contrary to the satellite TLT data Why not show the 850 300 mb data set in the presentation 11 Matthias Jakob says 21 Jan 2016 at 11 53 AM Hello Gavin thanks for the sobering post Quick question Why the climate normal 1951 to 1980 for the top graph rather than for example 1981 to 2010 Many thanks 12 Jim Dulian says 21 Jan 2016 at 12 13 PM I just saw a headline on MSNBC that said 2015 was the second hottest year on record Anyone know where that came from 13 Kevin McKinney says 21 Jan 2016 at 12 46 PM 7 Yes Denial exists in many dimensions and one of them is denial of selection bias that is to say it s clear that logically given the observed magnitudes of normal variability and more or less typical ENSO episodes most record warm years will also be El Nino years Though not all El Nino years will also be record warm of course Looking at the NCEI formerly NCDC data it looks as if the main exceptions to that so far were 1990 and 2014 which were both record warm and ENSO neutral So the El Nino explanation is a bit lacking in power to put it kindly That s comparing the ENSO binned monthly values from the briefing PDF to the annual climate at a glance values from the NCEI site Links below http www ncdc noaa gov sotc briefings 201601 pdf http www ncdc noaa gov cag time series global globe land ocean ytd 12 1880 2015 14 Dominik Lenné says 21 Jan 2016 at 1 16 PM If you tell me exactly what you mean by the word pause i can tell you whether there is one in the data Same holds for the word trend 15 James McDonald says 21 Jan 2016 at 1 48 PM John 7 I would suggest something even more direct e g This is the hottest El Nino year on record by far That takes the fact that it s an El Nino out of the running as an explanation for this particular record And it doesn t leave much room for a rebuttal But what about the non El Nino years 16 Jim Hunt says 21 Jan 2016 at 2 25 PM Thanks to Gavin team for swiftly and concisely answering my Reddit questions about the Arctic However I d still like to pursue the satellite radiosonde angle from slide 10 if I may The denialistas are currently bleating about 2015 wasn t hottest according to the satellites Hence my question What precisely if possible is being measured and then summarised in slide 10 17 Jim Hunt says 21 Jan 2016 at 2 29 PM Re Deep Climate says 20 Jan 2016 at 3 02 PM Welcome back DC Particularly since your latest article addresses some of my concerns about coverage bias 18 Dan Miller says 21 Jan 2016 at 3 25 PM There seems to be a labeling error in the Was there a pause animation The dotted line is labeled continued to 2015 which implies it s 1970 2015 which is what the green line is Perhaps the dotted line is 1997 2015 trend 19 AmishRakeFight says 21 Jan 2016 at 5 01 PM What stands out to me on the GISTEMP Annual 2015 graphic is that the only areas of the planet with cold anomalies are near the ice caps Greenland Patagonia and Antarctica I know I m not the first to notice in fact I have seen some discussion on other sites of the persistent cold pool in the North Atlantic near Greenland But most of those discussions used the NOAA graphics which don t show much around Antarctica I only check in on this site every now and then so I may have missed it Can anyone point me to any scientific discussion analysis or explanation of the cold pools near the ice caps on this website or elsewhere Thank you in advance 20 Joel Shore says 21 Jan 2016 at 5 49 PM 18 Dan Miller The dashed line is just taking the trendline from 1970 1997 and extrapolating that line The green line is fitting a new trendline over the period 1970 2015 21 Mal Adapted says 21 Jan 2016 at 6 59 PM Dominik Lenné If you tell me exactly what you mean by the word pause i can tell you whether there is one in the data Same holds for the word trend A guest post on RC last November focussed on four questions Is there a pause or hiatus in warming Has warming slowed compared to the long term warming trend Has warming lagged behind model derived expectations What physical mechanisms underlie the hiatus That helped me understand what is meant by pause The first two questions are primarily statistical while the second pair of questions are about our knowledge of the physical mechanisms of climate 22 Mal Adapted says 21 Jan 2016 at 7 27 PM Dominik Lenné also asked exactly what Gavin means by trend Gavin is the one who best knows what he means of course but this 2007 article in PNAS was helpful to me On the trend detrending and variability of nonlinear and nonstationary time series In this article a simple and logical definition of trend is given for any nonlinear and nonstationary time series as an intrinsically determined monotonic function within a certain temporal span most often that of the data span or a function in which there can be at most one extremum within that temporal span 23 barry says 21 Jan 2016 at 8 40 PM 14 Dominic Lenne If you tell me exactly what you mean by the word pause i can tell you whether there is one in the data Same holds for the word trend Pause refers to an apparent slowdown or stall in global temperature rise from 1998 Critics typically refer to the Remote Sensing Systems RSS satellite record of temps in the lower troposphere Here s the data http data remss com msu graphics TLT time series RSS TS channel TLT Global Land And Sea v03 3 txt What do you think For the other well known satellite data set University of Alabama Huntsville UAH you can use the official version 1 and the next version Beta 6 4 2 1 http vortex nsstc uah edu public msu t2lt tltglhmam 5 6 txt 2 http vortex nsstc uah edu public msu v6 0beta tlt tltglhmam 6 0beta4 txt If you want to experiment with surface thermometer data sets try these 1998 2014 http data giss nasa gov gistemp tabledata v3 GLB Ts txt http www metoffice gov uk hadobs hadcrut4 data current time series HadCRUT 4 4 0 0 monthly ns avg txt first column 24 phlambo says 21 Jan 2016 at 11 21 PM AmishRakeFight The short answer is meltwater changing Atlantic circulation Try here for more http www realclimate org index php archives 2015 03 whats going on in the north atlantic The Antarctic cooling I think is more complicated and has several articles on it 25 Urs Neu says 22 Jan 2016 at 6 19 AM As mentionned in earlier comments the influence of the current El Niño will be stronger on 2016 than on 2015 independent of the time lag being 2 months in Gavin s calculation or 4 months e g in Foster Rahmstorf 2011 for GISS data see also the Graph of MA Rodger in comment 4 The record years in global temperature always follow the El Niño winter 1998 2005 2010 The 1998 value was the result of El Nino starting in summer 1997 and ending in summer 1998 Since the ENSO index already between summer 2014 summer 2015 was positive and therefore increased GT in 2015 a bit 2016 will probably not stand out as much as 1998 but still for sure I d bet that 2015 will not be a standout peak like 1998 There s a high probability that 2015 will hold the record for one year only Thus with regard to global temperature 2015 is not an El Niño year 2016 will be the El Niño year that you should compare to 1998 2010 etc Furthermore the fact that 2014 and 2015 were so warm without being typical El Niño years leads to a number of interesting quetions concerning the reasons of the previous hiatus There were a number of reasons proposed to explain the weakening of the warming which each of them were purported to partly of fully explain the missing warming low ENSO index low solar maximum more aerosols ocean warming data coverage etc If all of them had been real they d have together explained the missing warming two or three times That means probably not all of them might be appropriate If we assume that we are somehow back on track now even without El Niño we can look at these factors that were proposed to slow the warming and see if they have changed recently Solar radiation hasn t ENSO has but seems to be only part of the game data coverage hasn t What about aerosols and ocean warming Well 2 years might be too short a time but it might still be interesting to include that in the discussion However if data coverage really explains the hiatus and if we are now back in the old trend and data coverage hasn t changed where are we really with global temperature 26 Chris Machens says 22 Jan 2016 at 7 00 AM We should point out that the cold spots around Antarctica and Greenland are likely indicating thaw freshwater runoff 27 MA Rodger says 22 Jan 2016 at 7 42 AM Although the tick tock of individual months is a bit trivial now the year is over and the annual anomaly is known here are the NOAA GISS rankings for the months of 2015 Ranking within the 1800 2015 record NOAA GISS 2015 1 16th 0 81ºC 16th 0 81ºC 2015 2 6th 0 88ºC 10th 0 87ºC 2015 3 5th 0 89ºC 8th 0 89ºC 2015 4 25th 0 77ºC 46th 0 73ºC 2015 5 10th 0 86ºC 22nd 0 78ºC 2015 6 6th 0 88ºC 22nd 0 78ºC 2015 7 17th 0 80ºC 46th 0 73ºC 2015 8 9th 0 87ºC 22nd 0 78ºC 2015 9 4th 0 92ºC 14th 0 82ºC 2015 10 2nd 0 99ºC 2nd 1 06ºC 2015 11 3rd 0 96ºC 3rd 1 05ºC 2015 12 1st 1 11ºC 1st 1 12ºC Rankings within the specific month of each anomaly through the year Jan to Dec NOAA 2nd Jan 1st 1st 3rd 1st 1st 1st 1st 1st 1st 1st 1st Dec GISS 2nd Jan 2nd 3rd 4th 2nd 1st 2nd 2nd 2nd 1st 1st 1st Dec For those curious about the differences in these rankings as the 2015 values demonstrate the two temperature records do disagree from month to month with an average difference of something like 0 05ºC So some discrepancy should be expected As GISS is wobblier month to month than NOAA in this circumstance of continually pushing for top spot NOAA with the less wobbles requires less of a margin to achieve a full slate top slots 28 Pete Best says 22 Jan 2016 at 11 05 AM What is the probability of 2016 being as warm if not warmer than 2015 if the additional warmth is 75 ACC and 25 El Nino as I think it has been stated 29 Russell Seitz says 22 Jan 2016 at 12 09 PM 26 Bear in mind that runoff water falling through a moulin gains 1 C per 200 meteres of fall so meltwter originating atop a high icecap melts more along the way and depending on transit time may exit at sea level warmer than its icy surroundings 30 Hank Roberts says 22 Jan 2016 at 1 58 PM cold pools near the ice caps Well there s more than just one thing going on But this is news https www google com search q antarctic elevation co2 heat radiation 31 Chris Machens says 22 Jan 2016 at 2 34 PM Cold blob North Atlantic https en wikipedia org wiki Cold blob North Atlantic 32 Chris Machens says 22 Jan 2016 at 2 36 PM Thanks Russel also Rignot pointed out in his AGU 2015 presentation that half of Greenland melt water comes from below the surface https www youtube com watch v 3p9uRxX95f4 33 Russell Seitz says 22 Jan 2016 at 10 42 PM Get a load of Delingpole s spin on the subject you can catch his drift from the lede No 2015 Was Not The Hottest Year Evah and the bizarre graphic that accompanies it 34 T G J M van den Berg says 23 Jan 2016 at 6 28 AM Wut dowedo f 16 jmps agaiiin 35 Hank Roberts says 23 Jan 2016 at 12 23 PM P S for the guy who asked about the cold spot in the Atlantic near Iceland RC has a recent thread discussing that http www realclimate org index php archives 2015 03 whats going on in the north atlantic Found with this search string site realclimate org cold map iceland ocean 36 Jim Hunt says 23 Jan 2016 at 1 09 PM Re Hank 30 This is news too Cold pools or not over on the Arctic Sea Ice Forum we re speculating about how low the 2016 Antarctic minimum sea ice extent can go http forum arctic sea ice net index php topic 1467 0 html Care to hazard an educated guess 37 Kevin McKinney says 23 Jan 2016 at 2 51 PM 33 Wow I m impressed Delingpole actually knows how to use WFT to compare trends Kind of makes it less likely that his untruths are accidental though 38 MA Rodger says 23 Jan 2016 at 7 21 PM HadCRUT also now in for December Their final monthly anomaly for 2015 sits even more dramatically than that for NOAA or GISS Ranking within the 1800 2015 record NOAA GISS HadCRUT 2015 1 16th 0 81ºC 16th 0 81ºC 14th 0 688ºC 2015 2 6th 0 88ºC 10th 0 87ºC 21st 0 660ºC 2015 3 5th 0 89ºC 8th 0 89ºC 15th 0 681ºC 2015 4 25th 0 77ºC 46th 0 73ºC 23rd 0 656ºC 2015 5 10th 0 86ºC 22nd 0 78ºC 12th 0 696ºC 2015 6 6th 0 88ºC 22nd 0 78ºC 8th 0 730ºC 2015 7 17th 0 80ºC 46th 0 73ºC 12th 0 696ºC 2015 8 9th 0 87ºC 22nd 0 78ºC 7th 0 740ºC 2015 9 4th 0 92ºC 14th 0 82ºC 5th 0 785ºC 2015 10 2nd 0 99ºC 2nd 1 06ºC 3rd 0 811ºC 2015 11 3rd 0 96ºC 3rd 1 05ºC 4th 0 802ºC 2015 12 1st 1 11ºC 1st 1 12ºC 1st 1 005ºC Rankings within the specific month of each anomaly through the year Jan to Dec NOAA Jan 2nd 1st 1st 3rd 1st 1st 1st 1st 1st 1st 1st Dec 1st GISS Jan 2nd 2nd 3rd 4th 2nd 1st 2nd 2nd 2nd 1st 1st Dec 1st HadCRUT4 Jan 2nd 3rd 2nd 3rd 1st 1st 1st 1st 1st 1st 1st Dec 1st 39 James McDonald says 23 Jan 2016 at 7 54 PM To repeat a question I asked on another thread Over the course of a few months this past summer Antarctic sea ice extent shifted from a recent pattern of being about 1M km 2 above average to hovering right about at average Is this likely to be related to the current El Nino or is it more likely just coincidence 40 Lawrence Coleman says 24 Jan 2016 at 6 18 AM The last 4 years to 2015 had an increasing rate of change anomaly which is a bit concerning I hope this current trend slows down or we are going to hit 1 5C very soon I have been closely watching the ocean temp anomalies for quite a while using null school and the 2 C warm pools seem to be growing As the current el Nino is showing the first signs of disintegration other warm pools are springing up Do politicians really understand that we are past time to inact a tangible reversal of GW I am not a accredited scientist and yet I can clearly see the dire urgency of the situation 41 Edward Greisch says 24 Jan 2016 at 5 22 PM https www dailykos com story 2014 01 29 1273455 Must see video How can it be so cold if there s global warming Must see video How can it be so cold if there s global warming 42 Piotr says 24 Jan 2016 at 7 02 PM 7 we d start to hear the denial meme no warming since 2015 or 2016 In fact if 1998 was anything to go by I think that s at least 5 years off You may be right you won t likely hear Stop the presses No global warming for 3 weeks now So for now we are stuck with the traditional The least squares linear regression trend on the RSS satellite monthly global mean surface temperature anomaly global warming for 18 years 8 months since May 1997 http www climatedepot com 2016 01 12 satellites no global

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  • Hiatus or Bye-atus? « RealClimate
    this article describes No problem with that So is it going to carry on rising or start a decline Historical scientific predictions said rising Observations show pause So public are sceptical What scientific tacit understanding am I missing 8 Jim Eaton says 27 Nov 2015 at 4 08 AM I m know this falls under the weather not climate category but we now have another unprecedented 2015 event happening right now Major hurricane Sandra a category 4 storm which fortunately just dropped to a 2 is headed towards Mexico just south of the Baja California peninsula This is the first major hurricane ever to exist this late in the year in the Western Hemisphere eastern Pacific or Alantic oceans As Dr Jeff Masters of the Weather Underground puts it Remarkable Hurricane Sandra exploded into a Category 4 storm with 145 mph winds overnight making it the latest major hurricane ever observed in the Western Hemisphere November 26 The previous record was held by an unnamed Atlantic hurricane in 1934 that held on to Category 3 status until 00 UTC November 24 Sandra is also now the latest Category 4 storm ever observed in either the Eastern Pacific previous record Hurricane Kenneth on November 22 2011 or the Atlantic previous record Wrong Way Lenny on November 18 1999 Prior to Sandra the strongest East Pacific hurricane so late in the year was 1983 s Winnie which topped out on December 6 at 90 mph winds Sandra is the first major hurricane in the Western Hemisphere that has ever been observed on Thanksgiving Day According to WU contributor Phil Klotzbach Colorado State University Sandra is on track to become the latest landfalling tropical cyclone on record for Mexico beating out Tara Nov 12 1961 An Air Force Hurricane Hunter mission is scheduled for Sandra on Friday afternoon It looks like Texas again and the southern plains are in for some extremely wet weather We can argue about how slow or fast sea level is rising but Mother Nature is showing us a lot of new changes that were generally predicted to occur decades into the future Hold on to your hats folks it looks like the roller coaster already is speeding down the tracks 9 Patrick says 27 Nov 2015 at 5 05 AM Oh dear It s sad when such convoluted arguments have to be invoked to justify past arguments when real science shows otherwise Remember Hoyle and the star formation saga Since the IPCC first made its predictions in 1990 all five of the longest standing global temperature datasets three terrestrial and two satellite have shown warming rates well below even the lower bound of the IPCC s very wide interval of predicted global warming Remarkably the IPCC s predicted rate of warming is three times the UAH observed trend of just 0 24 C since 1990 And now we read that CO2 residence time said to be 40 years not 1000 per previous claims 10 Silk says 27 Nov 2015 at 6 31 AM 6 Nobody could look at the temperature record and claim there was a pause Or at least nobody who wasn t in serious denial If those were crime stats and I were to claim to an audience that the data showed crime wasn t increasing I d be jeered out of the room The only people who can look at that time series and see a pause are people who would do anything to avoid having to reduce emissions Statistically that time series shows no pause did you bother to read the article Socialogically it also shows no pause UNLESS YOU WANT TO SEE ONE 11 Kevin McKinney says 27 Nov 2015 at 8 57 AM 6 Titus You may want to work on your reading for comprehension skills the statement that Temperatures in the last 20 odd years have been pretty flat or paused as this article describes is pretty much exactly wrong As to your question is it going to carry on rising or start a decline you may wish to read Tom O Reilly s comment at 4 12 chris says 27 Nov 2015 at 10 54 AM Titus the tacit scientific understanding you re missing is really just non tacit scientific understanding Our understanding of the world and thus the ability to make predictions is based on an understanding of the causal relationships and their magnitudes It s not based on just looking at stuff or fitting curves and extrapolating or whatever It s beyond question that the earth s surface temperature responds to an increased radiative forcing with warming Since we know that the greenhouse contribution to enhanced forcing is increasing no brainer we re emitting humoungous amounts of greenhouse gas and can observe that the solar contribution to forcing has been steady marginally reduced in fact since the 1950 s and have a good handle on volcanic contributions and so on our understanding tells us that the earth will continue to warm as the surface temperature comes towards equilibrium with enhanced forcing acrued and enhanced forcing still to come Temperature in the last 20 years haven t really been pretty flat have they NASA Giss has 1994 temperature anomaly of 0 32 and a 2014 anomaly of 0 74 That s 0 4 oC rise in surface temperature in 20 years 2015 is pretty certain to break the record 13 S Lewandowsky says 27 Nov 2015 at 11 10 AM 1 Silk Yes I think slowdown or fluctuation are good terms We settled on fluctuation in the BAMS paper 2 Andy Revkin Concerning your second point I am not aware of a recent systematic examination of the issue Freudenburg and Muselli showed in 2010 GEC 20 483 491 that new findings were more than 20 times as likely to reveal projections to have been too conservative than too alarmist There is also much evidence to suggest that scientists generally are too reticent e g Brysse et al 2012 Hansen 2007 Risbey 2008 We argue that this natural reticence is amplified by the contested nature of climate science Lewandowsky et al 2015 GEC But at the moment I cannot think of a more recent update of the Freudenburg and Muselli style analysis 3 Jim Baird Agree entirely Much to be learned and we contributed to the discussion Risbey Lewandowsky Langlais Monselesan O Kane Oreskes Nature CC 2014 5 Russell Interesting point about semiotics generally The specific question about sociological discontinuity escapes me however Can you clarify How would continuity be manifest And in what way could it be discontinuous 14 Mal Adapted says 27 Nov 2015 at 11 22 AM Titus Temperatures in the last 20 odd years have been pretty flat or paused as this article describes No problem with that You ve misread the article as it describes the opposite of your understanding From the first paragraph We have examined this issue in a series of three recent papers which have converged on the conclusion that there is not now and there never has been a hiatus or pause in global warming You go on to say So is it going to carry on rising or start a decline Historical scientific predictions said rising Observations show pause So public are sceptical What scientific tacit understanding am I missing Whatever tacit assumptions you are making you are missing the explicit understanding that temperatures have continued rising largely as projected the more so when observations from the last two years are included The observed slowing between 1998 and 2013 raised the 4th question asked in the OP with some answers emerging already for example last year Dr Schmidt and two colleagues published an article paywalled but I ll bet he d send you a PDF if you asked him nicely discussing how the CMIP family of models can better resolve short term noise to forcing by greenhouse gasses solar irradiance ocean circulation and anthropogenic and volcanogenic aerosols The public can thus be satisfied that climate science is progressing as it should 15 Adam R says 27 Nov 2015 at 11 36 AM Titus your observations have been incomplete it seems Even to the naive layman s eye surface temperatures do not appear flat if one looks at data through 2015 Observations show no pause They never did in the long term trend and now don t even in the naked year to year data That is what you are missing 16 Jim Eager says 27 Nov 2015 at 11 55 AM Titus wrote Observations show pause Only if you keep your eye on the dog But if you want to know about the trend in climate you need to keep your eye on the man Neil deGrasse Tyson explains https www youtube com watch v cBdxDFpDp k How long does it take to discern the underlying trend in climate from the noise of weather and year to year natural variation Longer than the so called pause Robert Grumbine explains http moregrumbinescience blogspot ca 2009 01 results on deciding trends html The pause never was 17 Treesong says 27 Nov 2015 at 12 45 PM Titus You ve missed the tacit understanding that there hasn t been a pause only a slowdown Try reading the article 18 Chuck Wilson says 27 Nov 2015 at 2 07 PM Titus 6 You are missing an understanding of the 1st Law of thermodynamics and the role that forcings play in climate The 1st Law for a closed system no mass exchange with surroundings but heat exchange says that the increase in internal energy must equal the net heat that entered the system minus the work done by the system The net heat is the absorbed energy from the sun minus the thermal radiation escaping to space The work is negligible try telling that to someone whose house was ripped apart by Sandra but it is true The system is the atmosphere the oceans the land down to a few hundred meters the cryosphere NOAA MSUs see UAH ARGO and predecessors boreholes and GRACE track the thermal state of these elements of the climate system Internal energy of the climate system has increased by about 275 ZJ since 1971 Box 3 1 of IPCC AR5 WG1 So where did this energy come from Murphy et al 2009 show us that added greenhouse gases have added several times this amount of energy over that time period Humans added those gases Those gases added energy to the climate system by reducing the amount of thermal radiation escaping to space the greenhouse effect and the internal energy went up It is a causal chain A climate with higher internal energy is expected to have warmer temperatures less ice and more water vapor All that has happened The correlation between global average surface temperature GAST and CO2 abundance is not perfect because the elements of the climate system exchange energy with each other in chaotic ways What causes ENSO the PDO the AMO But energy is governed by the 1st Law and the measurements show that the internal energy of the climate has gone up Quantum mechanics GHG absorption in IR tells us why We do not expect any major downturn in GAST because we are still increasing the abundance of GHGs and they will continue to increase the internal energy of the system with attendant increases in temperatures melting and water vapor content of the atmosphere Chuck Wilson Golden Colorado 19 Chuck Wilson says 27 Nov 2015 at 2 42 PM Thanksgiving I am thankful for this article and grateful to its authors for clarifying much over the years Too late for my last class but in time and bookmarked for the next one I am thankful for the return of RealClimate org to normal web life 20 Barton Paul Levenson says 27 Nov 2015 at 5 34 PM Titus at 6 Try here http bartonlevenson com 30Years html http bartonlevenson com NoWarming15Years html 21 John Drayton says 27 Nov 2015 at 7 42 PM Titus asks What scientific tacit understanding am I missing Titu what you seem to be missing is a connection to actual observations You claim to observe that the earth has been warming since the end of the little ice age of the mid 19th century but supply no evidence In fact on the page you comment on are graphics indicating a mild decline from mid late 19th century through to early 20th century You also claim that temperatures in the last 20 odd years have been pretty flat or paused as this article describes yet the authors of the article explicitly state We have examined this issue in a series of three recent papers which have converged on the conclusion that there is not now and there never has been a hiatus or pause in global warming Finally you say ask So is it going to carry on rising or start a decline concluding that observations show pause again with no evidence I have no idea how you can hold on the the idea that observations show a pause especially in light of the fact that 2014 was a record high and that 2015 is pretty much guaranteed to exceed 2014 by a notable margin 22 R Zaharia says 28 Nov 2015 at 1 58 PM Respect and Relief It seems to me that the 3 of you deserve to be commended While reading this article the words that came in my mind were Fisrt class thinking Fisrt class analysis Excellent science All the more of this feeling since I happened to come on this web page just after reading the Lamar Smith Bullying letter of Nov 4 to K Sullivan Head of NOAA on the very same issue But with a Stone age approach Relief is a common feeling when going from a stinking place to a nice garden or an art museum Indeed a well written to the point article may be seen as an artwork What a pity that the House Committee on Science Space Technology doesn t know the value of reprocessing What a pity that these folks still ignore that one of the best values they are supposed to overlook for taxpayers sits in periodical reprocessing of available time series of observations more particularly before performing Met reanalyses 23 Barton Paul Levenson says 28 Nov 2015 at 6 12 PM Because I don t want to post in the about to die November page I d like to beg the editors indulgence and post a very minor announcement here I ve added a new page to my web site giving the reasons we know the present warming to be artificial http bartonlevenson com AnthropogenicCO2 html 24 Vincent says 28 Nov 2015 at 6 55 PM First from what I ve observed on Facebook and elsewhere the global warming denialists have since a while moved onto claiming that the satellite data specifically the RSS analyses don t show any warming and they just ignore the ground measurements despite being direct measurements Second on a more serious note you say you re calculating correlation coefficients on annual global temperature means But how is such an analysis justified A P value represents the odds that the actual data were found assuming that the null hypothesis is true in the population that the random sample was drawn from so if a P value is too small we reject the notion that the null hypothesis is true in the population But when talking about an interval of annual global means these values aren t drawn from a greater population of annual global means that we want our sample to generalize to after all we just want to say something about that specific interval It doesn t make sense to me to use annual global mean as a random factor So why would a simple correlation calculated over annual global means be appropriate I don t understand that Or I m missing something If someone could point out what I m misunderstanding I d greatly appreciate that Sorry if I m being stupid 25 Titus says 29 Nov 2015 at 4 10 AM Just to clarify I did not come up with the word pause That came from the article I said temperatures were pretty flat I may add here that they are very flat in consideration of what was strongly predict years ago Patrick 8 explains it much better than I Oh dear It s sad when such convoluted arguments have to be invoked to justify past arguments when real science shows otherwise Read his entire comment I d say he s close to what the general public think 26 Chris O Neill says 29 Nov 2015 at 6 04 AM Titus I observe that the earth has been warming since the end of the little ice age of the mid 19th century No you didn t There was no observed warming in the second half of the 19th century http www woodfortrees org plot hadcrut4gl to 1900 trend plot hadcrut4gl What scientific tacit understanding am I missing If you miss facts such as the above then you re certainly going to miss understanding 27 Don Cox says 29 Nov 2015 at 6 48 AM How the graph looks depends very much on whether you plot a one five ten or twenty year running average The longer the period the less any pause will show We also need to distinguish clearly between the temperature the change in temperature and the rate of change in temperature This kind of thing can confuse the general public 28 Chuck Hughes says 29 Nov 2015 at 1 43 PM Here s a little caveat that the Scientific Community should take into serious consideration when discussing emerging Scientific Truths to the public The study of 160 000 people by the Organization for Economic Cooperation and Development which is composed of two dozen developed nations found that U S

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