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What has global warming done since 1998?

What the science says...

Select a level... Basic Intermediate

Every part of the Earth's climate system has continued warming since 1998, with 2015 shattering temperature records.

Climate Myth...

It hasn't warmed since 1998

For the years 1998-2005, temperature did not increase. This period coincides with society's continued pumping of more CO2 into the atmosphere. (Bob Carter)

Even if we ignore long term trends and just look at the record-breakers, 2015, 2014, 2010, and 2005 were hotter than 1998.

The myth of no warming since 1998 was based on the satellite record estimates of the temperature of the atmosphere.  However, as discussed in the video below by Peter Sinclair, even that argument is no longer accurate.  The satellites show warming since 1998 too.

There's also a tendency for some people just to concentrate on atmospheric or surface air temperatures when there are other, more useful, indicators that can give us a better idea how rapidly the world is warming. More than 90% of global warming heat goes into warming the oceans, while less than 3% goes into increasing the atmospheric and surface air temperature.  Records show that the Earth has been warming at a steady rate before and since 1998 and there is no sign of it slowing any time soon (Figure 1). 

Fig 1

Figure 1:  Land, atmosphere, and ice heating (red), 0-700 meter ocean heat content (OHC) increase (light blue), 700-2,000 meter OHC increase (dark blue).  From Nuccitelli et al. (2012).

Even if we focus exclusively on global surface temperatures, Cowtan & Way (2013) shows that when we account for temperatures across the entire globe (including the Arctic, which is the part of the planet warming fastest), the global surface warming trend for 1997–2015 is approximately 0.14°C per decade.

Ultimately, every part of the Earth's climate system is warming, and has continued warming since 1998.

This rebuttal was updated by Kyle Pressler in September 2021 to replace broken links. The updates are a result of our call for help published in May 2021.

Last updated on 29 September 2017 by dana1981. View Archives

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Further reading

Tamino further explores the warming trend since 1998 in Garbage is Forever and Wiggles.

I've kept my original treatment of the subject as other websites hotlink to the images. My original treatment uses similar arguments to Fawcett and Jones 2008 although their analysis is much more rigorous (as you'd expect in a peer-reviewed paper).

Further viewing


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Comments 351 to 400 out of 414:

  1. Hi all.  I am a high school AP Envrironmental Science teacher who does his best to stay "up-to-date" with the science of climate change.  I have a quick question for anybody willing to help.

    I keep reading about the current hiatus, pause, stagnation, etc. in global surface temperature and I am fairly confident that I understand the meaning of statistical least well enough.  My question is, however, with 2014 being another record year have we gotten past the "no statistically significant warming" bit yet or was 2014 not sufficiently anomalous to bring us out of the "hiatus?"  Any help here would be great.  

  2. Hi chud, the nature of noisy data means that you can't expect to see statistically significant trends over short time frames. Hence, you will almost always be able to say "no significant warming since <some year>" if you draw the line from the last major el nino year. It's not that unlikely that if 2030 is a la nina year, we will be able to draw a line from 2015, and say "no significant warming in 15 years!".

    When every major temperature set shows significant warming since 1998, all the so-called skeptics will do is change the meme from '98 to '02, then '05, then '10 etc etc. It's an utterly meaningless claim.

  3. plfreeman and stewart:  Here is a relatively simple statistical analysis for 2014 global records which indicates there is a special cause for the percentage of hot all time records.

    Stephen Thomas  (
    M.S., Mathematics, Northwestern

    Based on around the globe weather station reports and historical records, in terms of all time Hot and Cold records set: 74 New all time high temperature records were set this past year (NOAA global records summary) and 19 New all time cold temperature records were set this past year. So we have set 79.6% Hot records vs. Cold records. Based on the binomial distribution for percentages, assuming a 50% underlying probability (the null hypothesis of no global warming) the expected range for 50% based on N=93 is 34.4% to 65.6%. I.e., expect by chance over 99% of the time for actual percentage to be between 34.4% to 65.6%. But for 2014 the actual percentage of Hot records set out of total records set is 79.6%, which is considerably above the P-chart 'upper control limit' of 65.6%. We see the data gives us an objective conclusion that it is NOT 50%. There must be a special cause.

  4. The currently available temperature records show pauses in  warming from about 1880 until about 1910 and from the early 1940's until the early 1970's.  Approximately equal length periods of warming were interspersed with the pauses.  If this possible pattern was real then there was cause to expect another pause in warming to begin at about the year 2000.  It appears that such a pause did begin but now its presence is in dispute.  It would probably be a good idea not to put too much emphasis on individual years (or months) during this period  but rather assess whether or not it was a pause at ar near its probable end around 2030.   


    [TD] It is best to read the original post before commenting. Actually read it. Thoroughly. This post is not about individual years or months. After you read the Basic tabbed pane, read the Intermediate one, and watch the Denial 101x video at the bottom of that tabbed pane. Then read the recent post "In a Blind Test," not just because of that most recent blind test being reported, but more importantly for links to the multiple previous studies using a diversity of approaches that all found there has been no recent pause in the long term warming trend. It simply does not exist. The assessment you suggested in your comment has been done already. Repeatedly. To exhaustion.

  5. I still say wait and see.  Some of the years during the next pause (about 2060-2090) will be even warmer than those during this pause.  


    [TD] Now you've focused on a topic that does not belong on this thread. If you want to claim that there are natural periodic cycles in temperature, first read the post countering the myth that It's a Natural Cycle, including watching the Denial 101x video at the bottom. Probably you are repeating reverberations from the debunked Loehle and Scafetta data torturing, so you should read that post too. Then comment on one of those threads. For yet more debunking of what climate statistician Tamino calls "mathturbation," enter "mathturbation" into the Search field on his site.

  6. billev... Except that it's been fairly well established at this point that there's been no pause. Any potential pause from natural forcings is overwhelmed by the much larger radiative forcing of man-made greenhouse gases.

  7. I base my observations on a perusal of the NOAA temperature charts from 1880 to the present.  Those charts indicate pauses in temperature rise from about 1880 until about 1910 and again from the early 1940's until the early 1970's.  A few years ago these same charts indicated a leveling of average global temperature.  It seems thjat in recent years the scale of these charts has been changed to make them smaller and render it difficult to discern a trend.  I am also concerned that officials of NOAA and possibly GISS have given press releases citing particular years and months as the hottest on record.  I would prefer that they remain dispassionate providers of the most accurate temperature data possible.  I am confused be the response to my comments.  I thought, by virtue of its title, that this thread was concerned with the plausability of any pause in the rise of global temperature.     


    [TD] You will be less confused if you actually read the original post. No, wait, don't type yet; really read it for understanding. Now read my previous comments to you. Again, read carefully for understanding. This original post is about the myth of a recent pause in the long term trend of global warming. There is another post devoted to the other myth you asserted, which is that natural cycles are responsible for pauses, coolings, and warmings. (Edit: Better phrasing is that the myth you asserted is that the recent warming circa 1970 on is due to natural cycles rather than anthropogenic causes.)

    You are incorrect about the scale of the charts being changed to make trends harder to see. The data all are available for anyone to graph, and there are a bazillion graphs from both official and unofficial producers, with a variety of scales and many that are user-settable. One example is the Skeptical Science trend calculator. Statistical analyses do not in any way depend on graph scales.

    Your concern over press releases is off topic. It is also bizarre since those agencies merely are stating facts that you and anyone else can check.

  8. Billev...  You really wouldn't want to try to discern a trend by eye, since your eyes can easily deceive you. You need to test for trends through statistics. As the moderator pointed out, SkS has a trend calculator you can use to test trends on any of the data sets for any time period you like.

  9. Billev @358 (and prior)

    1)  Using GISS LOTI, the peak 18 year trend in recent decades is from 1992-2009.  At 0.23 C per decade, it is 39% greater than the trend from 1981-1998, and is statistically significant.  Given that, claiming the "pause" or "hiatus" started "...about the year 2000" is clearly based "put[ting] too much emphasis on individual years" - specifically, 1998.

    2) The following are the successive record years (including ties) since 1880:

    Year Record Interval
    1880 -0.21
    1881 -0.12 1
    1882 -0.11 1
    1900 -0.09 18
    1926 -0.09 26
    1931 -0.09 5
    1937 -0.02 6
    1940 0.08 3
    1941 0.13 1
    1943 0.14 2
    1944 0.25 1
    1980 0.28 36
    1981 0.33 1
    1987 0.34 6
    1988 0.4 1
    1990 0.44 2
    1995 0.46 5
    1997 0.48 2
    1998 0.63 1
    2002 0.63 4
    2005 0.69 3
    2010 0.72 5
    2014 0.75 4

    (Interval is the number of years since the last year that set or equaled the then previous temperature record.)

    As you can see, three new records have been set since 1998, and 1998 was equalled in 2002 as well.  Your other putative "pause" is noted for the complete absense of records in the interval.  Therefore the two phenomenon are not analogous, even if we ignore the fact that the current "pause" is an artifact of cherry picking 1998 as the start year.

    3) The following is the GISS LOTI showing the running five year mean:

    Looking at the five year moving average, it is very clear that there has been a more or less constant upward trend from about 1915-1970 with a single large excursion peaking in 1945.  The description of the temperature history as a warming trend from 1910 to 1940 followed by a cooling trend/pause from 1940-1970 imposes a preconcieved pattern onto the data, and is not supported by that data.  The 60 year sawtooth or sine pattern in the temperature data are a figment of the imagination.  Therefore even if we were to be so statistically adventurous as to infer a long term cycle from a single repetion of the cycle, you would have no basis for predicting a pause from about 2000 (said pause not existing in any event).

  10. The chart, just above, shows me a pause in temperature rise from 1880 until about 1910 and one from the mid 1940's until about the mid 1970's.  it also could be indicating another pause beginning about 2000 but that is not clear from this chart.  I realize that I used my eyes to observe this chart but wasn't it intended that I do that? 

  11. billev... You have to understand that global temperature changes for physical reasons. The 1880-1910 trend is during a period when human greenhouse gas emissions were still very low, but starting to have an effect. At that point in time, natural forcings could have more of an influence on global temperature.

    Then, think about what was happening from the 1940's through 1970, and what specifically happened in 1970. First you had WW2 and then a huge amount of industrial growth post war, which put out atmospheric aerosols which tend to block sunlight and cool the planet. Then 1970 saw The Clean Air Act, which cleaned up a large portion of the aerosol output and, essentially, unmasked the underlying greenhouse gas forcing.

  12. billev - I would suggest reading (and commenting upon) the Why did climate cool in the mid-20th Century, or possibly It's a natural cycle, where your recent posts would be relevent. They aren't in this thread. 

    Hint - Cooling mid-20th century isn't due to a natural cycle, but rather primarily due to anthropogenic factors and volcanic variability. Nor is there any reason whatsoever to expect some cycle-induced cooling to kick in. 

  13. Following KR's suggestion, I have responded to billev elsewhere.

  14. Tamino yesterday posted temperatures with updated removal of influences for solar, reflective aerosols, and El Nino. Still no recent pause visible. Surprise.

  15. Hi, The link to the ECMWF analyis of the HadCRUT data is broken. Any chance of a link to this study? Have Googled but can't find anywhere. 


    [DB] An archive copy of the study can be found here.  I've also updated the rebuttal with this same link.

  16. 2 things... 


    using a trend as an answer as to why the current data doesnt matter is crazy. you cant say it doesnt matter look at the other 10 data points they lead to this...  obviously they dont if they did there would be no cooling trend... lets break it down.. this is like a straight a student someone who had got 10 straight A's but on the final got an F..  The Proffesor then grades accordingly.. but the student says no... you didnt take into account the "Trend" my grade should be reflective of the past 10 measurements... would that really fly?


    Also come on guys words have meaning.. you cant say that 2010 was the highest temerature on record, it was tied with 2005.  if 2005 was just as warm 2010 cant be higher... 

  17. AJC1973 @366 : You will need to explain yourself more clearly ~ since your post [above] does not make much sense.

    Words ( even "Proffesor" ) can have meaning ~ but they need to be allied with commonsense thinking. Is the world warming . . . or isn't it? The evidence shows clearly that it is . . . and word-games cannot alter the physical reality of it all.

  18. AJC1973 @366:

    1)  You seem very confused about trends and variation.  The point about the final point of data is that it tells you nothing about any other data point.  In contrast, the trend sums up information about all the data, and does so in a way that usefully informs you about the next likely datapoint (see video below).  People who only want us to look at the first and last datapoint are really cherry picking - trying to blind us to the truth by the carefull exclusion of data contrary to their narrative.

     (Further comments)

    2)  Words to indeed have meaning, and expostulating about that fact won't lead us to ignore those meanings.  Thus, here are the four most recent annual temperature records for the three major surface temperature records:

    Year_____: _1998, _2005, _2010, _2014

    HadCRUT4: 0.536, 0.544, 0.559, 0.567

    NOAA____: _0.63, _0.66, _0.70, _0.74

    GISS_____: _0.63, _0.69, _0.72, _0.74

    As can easilly be seen, in each case 1998 < 2005 < 2010 < 2014.  You want to say that 2014 = 2010, but that is not true.

    Probably you have been confused by people inaccurately talking about a "statistical tie".  That is because in each case 2005 lies within the uncertainty interval of 2010.  Therefore, given the data it is statistically possible that 2010 was actually the warmest year, but the nominal value (or the mean estimate) places 2010 above 2005.

    Note, this is not a 'statistical tie' (or worse, a case where 2010 is 'statistically indistinguishable' from 2005).  That is because there are years which may have been (given uncertainty) warmer than 2005, but which could not have been (given uncertainty) warmer than 2010.  Put another way, the probability that 2010 was the warmest year given the data is greater than the probability that 2005 was the warmest year.

    Note, the same can be said of the relation between 1998 and 2005, and 2010 and 2014.

  19. I went looking for whatever set of satellite data were least challengeable, and found the excellent graph by Dr. Mears.  Since he is a firm believer in AGW and would not be somehow trying to manipulate data to make less of any warming trend, that seemed the safest bet.

    However, examining his graph, what I see is that, neglecting the spike at 1998, the ups&downs of the chart from about 1994 or so make a classic SPC chart that shows a stable process.  While the various computer programs predict a 1 to 1.5 increase in the time, the actual level is about 0.3 deg above centerline.  Clearly the models are badly flawed, and in science, when your models don't work, you discard them.  Thus it is not some kind of biased "denial" to take the position that there is no compelling evidence of a warming trend.  Dr. Mears goes into all the reasons why we are seeing a "pause", but this is basically trying to discount what his own data indicate, based on the belief, not reasoning, that there MUST be warming going on.

    The counter arguments of skeptics deserve something more than personal attacks on "denialists".  The very use of such terminology is unworthy of those seeking truth.  In Science the back and forth of discussions is supposed to be the norm up until there is compelling evidence to prove an hypothesis is valid.  There may yet come clearer evidence of warming, or some of the alternative theories about sunspots, etc, may gather more evidence.  Until then it would behoove all of us  (yes, I am a scientist with degrees and long practice) to remain at least tolerant of views other than our own.


    MarDivPhoto @369.

    I assume you refer to the Carl Mears blog post here. You seem to be arguing here that it is Mears who is in denial, not you. That isn't a very good example for the "back & forth of discussions" you describe as being the stuff of science. And in dismissing Mears and his analysis, you replace it with "sunspots, etc." It is all a bit shallow, do you not think?

  21. MarDivPhoto... Dr Mears actually suggests that the satellite data is not so good. On the blog MA Rogers links to he clearly states, "A similar, but stronger case [for model/observations] can be made using surface temperature datasets, which I consider to be more reliable than satellite datasets (they certainly agree with each other better than the various satellite datasets do!)."

    You can't casually discard models when you don't fully understand the accuracy of the observations. It's just as likely, at this point, that models are doing a better than observations are.

  22. I think at the heart of the problem is the question of "what is a good diagnostic for global warming". Neither the tropospheric temperatures (which the satellites attempt to measure) nor the surface temperature record (what actually matters to most to human activity) are particularly great because both are very noisy datasets with short term variations dominated by ENSO. You need long time spans to assess underlying behaviour. Tropospheric measurements (RSS/UAH) are particularly sensitive to ENSO showing much larger responses to La Nina and El Nino events than the surface record. Arguably, OHC is the best diagnostic we have. See here for more detail.

    On top of that, determining ttropospheric temperatures from satellite MSU measurements is a tough problem. MSU isnt only way to measure tropospheric temperature - radiosondes also do it. However, it looks like the measurements systems have started to diverge.

    Watch for science being published on this.

  23. For MA Rodger-

    Ah, the instant attack, how sadly predictable.  No, I was not accusing Dr. Mears of being in denial, I was pointing out that he posted data that is easily interpreted one way, and then chose to offer reasons why it should not be interpreted that way.  I did not immediately claim he must be wrong, or that there cannot be a warming process going on.  I do not accuse those who believe strongly in AGW of being "alarmists" just as I don't think people should talk about "denialists".  I believe in forming hypotheses and looking for data to confirm them, and that sometimes it will take time and more data to provide either the compelling evidence to support them, or to demonstrate that the reality is somehow different than was thought.  After which the scientist goes back to the drawing board, so to speak, and starts thinking anew about how to understand the reality that has so far proven elusive.  Hasn't this happened myriad times in science that we all know about?

    Science in the ideal is practiced with total objectivity, and although we humans are probably incapable of achieving that ideal, as scientists we are supposed to be working really hard at it.  The discussion of Climate Change long ago fell into deep pools of emotion on both sides, which is most unfortunate.  But there should always be room for discussion without rancor among scientists.

    As was pointed out recently at a congressional hearing, in very many areas, including NYC, the intelligent thing to do is to prepare for higher water and more frequent storms, rather than fighting about how to make people use less energy.  After all, assuming AGW is actually valid, since we have no remotely practical ways to remove gigatons of CO2 from the atmosphere, then preparation for coming changes is mandatory.  If AGW is valid, then we'll be better off, and if it turns out we don't need the levees, dikes, etc, there really won't be any harm.  Shouldn't that be a focus for leaders all over the world?  Especially since India and China are not about to stop their increase in the use of coal.

  24. " I believe in forming hypotheses and looking for data to confirm them, and that sometimes it will take time and more data to provide either the compelling evidence to support them, or to demonstrate that the reality is somehow different than was thought." And for some reason you think this isnt what is happening in climate science? It also appears that you  are also assuming that slower warming in say RSS is evidence against the AGW hypothesis? For this to be the case, then you need to present the case where climate science would think the current RSS measurements incompatible with theory. I am not aware of such published science. Quite the reverse.

    You are also presenting a false dichotomy of adapt to change or use less energy. A third option is change to non-carbon generation. Studies to date suggest the latter is cheaper than adaptation (though yes, it should have started to happen decades ago). It is also more equitable because richer nations created the problem, and yet many poorer nations will feel the more severe effects and be less able to adapt.

    Proposals have mostly focussed on getting sharp reduction in FF use in developed nations (they are both responsible for most of the damage to climate and most able to afford the transition), while giving poorer nations longer to change. If you want more pressure on China/India etc. then you put border carbon tax on goods created FF-generated energy.

  25. MarDivPhoto [ @373 ] . . . You would considerably improve your "total objectivity" if you looked at the context of the situation you describe.

    ~ Dr Mears has made a number of suggestions on probabilities and possiblities regarding surface temperature short-term variations [ and not including his half-humorous Point No. 4 ].   Remember also, his blog entry was written in September 2014; well before the "warming effect" of the present big El Niño.  [ an El Niño, of great embarrassment to denialists ]

    ~ Also implicit in his comments, is the objective background of the [surface temp]  warming/not-warming question.  We are dealing with a real physical world here . . . not some thought-experiment where coins are tossed / dice are rolled / etcetera.  Thus, we have to deal with the observed couple of watts/m2  of planetary heat gain, which is occurring every day and every month of every year (volcano eruptions excepted!).

    Where has this heat energy gone, and where is it going?  No, it hasn't been teleported onto the Starship Enterprise or been teleported into the nearest Black Hole.  MarDivPhoto, you yourself know [since you deny being a denialist] that this ongoing inflow of heat energy is 90% going into the oceans . . . and so it would be foolish to turn a blind eye on such a large fact.  A fact, which (so to speak) tilts the playing field in favour of long-term surface warming: and which renders it ridiculous to hint that a "hiatus" is equally as likely as a "warming".

    Indeed, ridiculous to suggest a "hiatus" in the sense of a "halt" in AGW.


    (off-topic) As to building dikes & levees : of course that is an intelligent move, and sadly necessary . . . but it is far from intelligent to abandon effort to reduce the size of the CO2-caused problem.

    "If AGW exists" . . . is a vacuous phrase, in view of the vast amounts of melting ice, the rising sea-levels, and all the other objective evidence of our global warming problem.  It's a matter of overall context, isn't it !?

  26. I guess I have to repeat the simple observation that the up&down pattern of temperature shown in the Mears graph and the fact that what increase it does show is tremendously less than the models indicate all give ample reason to question the assumption that we are in the midst of a CO2 caused global warming.  People can bring up all the other arguments they like, but until we see a much clearer picture of unmistakeable effects, it is not justified to claim that we absolutely know and understand what is going on.  Glaciers are melting, but they always have.  Greenland was a great deal warmer 800 years ago than is has been since then, and CO2 was low back then.  Artic and Anarctic ice has increased and decreased in the past.  Remember when everyone jumped on Katrina as the first superstorm from AGW?  But we haven't seen a steady procession of them since.  Everyone likes to jump on anecdotal events as long as whatever it is supports what they want to support.  That's not science.

    If anyone thinks for a millisecond that the world is going to seriously back off burning coal, oil, gas, and wood for that matter, they are indulging in fantasy.  And again, we cannot take the CO2 out of the air, so it's not remotely a "either/or" proposition, if the theory is valid, then preparing for it is as basic intelligence as it gets.

    Sun and wind will never make up more than a fraction of the energy that modern life desires and demands.  Planes will only fly by jet engines, and electric cars, trucks, trains, all get their kilowatts from some form of enegy generation, which right now is mostly from burning things.  Logically we should be jumping all over 4th generation nuclear plant designs and funding research into fusion hugely, but somehow most of the people who are enthusiastic about reducing CO2 output reject any such ideas.

    The rising sea levels... well, the sea has been rising for a very long time, very slowly.  So far we haven't seen any of the many low lying islands of the world disappearing, not even the very low sand islands off the coast of my state.  Everyone refers to these events as if half the Antarctic and all the Artic are gone, and the sea is up by a foot or more, but none of that has happened so far.

    When the water in the Mindanao Trench comes up in temperature, then we'll know a lot.  But the mass of the oceans and the heat capacity of water combine to be one heck of a heat sink, so in fact even if energy were being trapped, it would take a very, very long time to have any effect there.

    And someone just had to throw in the "denialist" term again as part of their approach, which tells me that it's time for me to bow out of this exchange.  Apparently there is no escaping the "if you're not with us, you're against us" mentality, that is not part of any truly reasonable thinking, whethere one has studied science or not.  The points I've tried to register were about real science staying open to discussion without rancor and personal attacks, and that there's enough evidence to justify some questioning of the current popular theory about Climate Change.  Clearly such thoughts are not welcome here.

  27. The models do not attempt to calculate what RSS/UAH measure. A global surface trend is extracted from models. Comparing RSS to model output is not a valid comparison. Furthermore, it is not a way to validation of models. Your attempt to do so would suggest that you are judging climate science without actually reading the WG1 report.

    Models have ENSO-like features but they cannot predict what ENSO will actually do and every model run will produce a different realisation. A proper validation is done when you compare estimates of surface temperature (not troposphere) to the range of model outputs (corrected for actual forcings). Models are doing fine in this comparison.

    "Glaciers are melting, but they always have." Huh? They advanced during LIA. Glaciers are integrators of climate. Climate has changed in the past (when the external forcing change) and glaciers change with them. You seem to be implying that glaciers have made unforced changes  but where is the evidence for that.

    Did you actually look at the OHC graph I pointed to? How do you explain that by unforced natural variation?

    If you look at science on hurricanes, you will see that AGW increases SSTs which fuel hurricanes but also increase upper level shear which hinders development. Which wins? Again you are making claims on climate science which are not actually made. That is a strawman argument and I would expect a scientist to know better.

    I will other bits of your gish gallop to others (or moderators) but you again you are making a bunch wild claims with no supporting evidence in violation of comments policy on this site. Uninformed comment in not welcome on this site. You appear to be simply repeating long debunked claims of sort you hear on Fox news or pseudo-skeptic blogs.

  28. What MarDivPhoto @376 said:

    "The rising sea levels... well, the sea has been rising for a very long time, very slowly."

    What the science says:

    Note in particular the flat, and indeed, recently declining sea levels over the last 3000 years in Fig 13.3 a.  That decline reversed itself sharply about 1850 as seen in Fig 13.3 b and e.  Fig 13.3 is assessed in greater detail by SkS here:

    The 1901 to 2010 figure is given as 1.7 [1.5-1.9] mm per year by the IPCC, so that the current rate (3.2 mm per year) is nearly twice the twentieth century average.  aClearly MarDivPhoto's claim is simply not based on the data, whether assessed on millenial or centenial time scales.  It is probably based on the common denier meme which averages sea level rise from the Last Glacial Maximum to the current era paying no attention to even thousand year long patterns in the data which clearly show such an average is deceptive rather than informative.

  29. Again, MarDivPhoto [ @ 376 ], you demonstrate a decided deficiency in "total objectivity" in your assessments.

    "Sun and wind will never make up more than a fraction of the energy that modern life desires and demands" [unquote] ~ there indeed you are indulging in fantasy . . . unless you are intending to include as "fraction" some very large fractions like eight-tenths and nine-tenths.

    Yes, fusion power generation of electricity would doubtless be desirable : yet it fails the "practicable alternative" test, in that it is likely many decades away (and trillions of dollars away, probably). Far too much opportunity cost, there, for the next few decades.

    Fission power generation ~ yes, practicable but not so practical on the "soon and large" scale we need. Think of the vast opportunity cost; the slow build and distant commisioning dates; the vulnerability to terrorist assault [kidnap of radioactive material, particularly]; and the vast decommissioning costs.  And sadly, there's always the NIMBY politics.

    So, seeing such a gamut of problems, why would you wish to propose fission power . . . if no AGW problem exists (in your opinion) ??


    You yourself claim an absence of "much clearer picture of unmistakeable effects" [of global warming] ~ yet this is a point which almost every climate scientist in the world would disagree with (not to mention every peak scientific body, too).  In effect, they describe your position as lacking objectivity.

    Nevertheless, MarDivPhoto, keeping an open mind (in readers here) about such an important point . . . you sound like you should have little difficulty in stating a short list of cogent criteria which you would see as clear unmistakable clinchers re non-trivial global warming.

    * No, that wasn't a trick question; I'm not trying to play "gotcha"; nor do I wish to play lawyer-type  salami-slicing  logic-chopping games where you get berated over a tenth of a degree here, a half degree there, or a thousand Gigatons of ice plus-or-minus.  No, none of such intellectual dishonesty, in the slightest.

    Though I am sure you realise that you will need to give non-trivial, non-catastrophic replies ~ remembering that such stuff as like: 100cm sea-level rise, zero sea-ice in the arctic summer, or the heat-induced uninhabitability of half of India . . . all those sorts of criteria are ones which I am sure an objective thinker would scorn to give (as being scientifically and morally unconscionable).

    So, MarDivPhoto . . . what say you ?

  30. What MarDivPhoto @376 said:

    "If anyone thinks for a millisecond that the world is going to seriously back off burning coal, oil, gas, and wood for that matter, they are indulging in fantasy."

    What the science says:

    "This moderate increase of 2% in 2013 compared to 2012 is a continuation of last year’s trend
    and of the slowdown in the annual emissions growth.  The actual increase of 2012 compared to 2011 was 0.6 Gt or 1.7% (excluding leap year correction) and both are about half the average annual growth rate of 1.1 Gt or 3.8% since 2003 (excluding the 2008–2009 recession years). Note that the average annual emission increase in the 1995–2002 period (after the large decline in energy consumption in the former Soviet Union countries) was about 1.2% or 0.4 Gt CO2 per year. With the global economic growth of 3.4% and 3.1%, in 2012 and 2013 respectively, a further decoupling of the global economic and emission trends can be observed. This decoupling is consistent with the increasing service sector share (growing by 1.5% and 1.8% in 2012 and 2013 on average in middle income countries, including China) to the overall gross domestic product, at the expense of more energyintensive industrial activities."

    Clearly economic growth is already decoupling from carbon emissions, which partly driven by increased relative production of renewable energy.  And contrary to MDP's assertions, Chinese CO2 emissions actually fell in 2014 (ie, the year after that covered by the report above):

    Indeed, globally CO2 emissions did not rise in 2014.  This has lead to some, probably premature, speculation that CO2 emissions have reached their peak.  More probably they will tend to rise slowly over the coming decade, but CO2 emmissions are rising far slower than BAU scenarios project.  That is because we are not in a BAU word.  Rather, we are in a Kyoto, and now Paris world in which there are solid commitments by major polluters to reduce CO2 emissions, backed up by actual deeds.

    Again MDPs' claim is based on what they would like to be the case, not on the actual data.

  31. MarDivPhoto,

    to address another of your wild claims, Jeff Masters, a national hurricane expert, says here:

    "Typhoon Melor powered into the Central Philippines on Sunday night, December 13 (U.S. EST time) as a Category 3 storm with 125 mph winds. This was slightly below its peak intensity as a Category 4 storm with 135 mph winds at 8 am EST Sunday, when Melor became the record-smashing 26th Northern Hemisphere Category 4 or stronger storm this year (previous record: just 18 such storms in 1997 and 2004,"(my emphasis)

    I was waiting for an end of year summary but your coment is so far off base and without factual support that I had to cite it.  This year crushed all the records for strong hurricanes.  "Unknown natural cycles" does not cut it against these records.  You appear to be in the group that says if the hurricane does not hit your house it did not happen.  Worldwide strong hurricanes are setting records.  

  32. MarcDivPhoto @373.

    You say "I was not accusing Dr. Mears of being in denial, I was pointing out that he posted data that is easily interpreted one way, and then chose to offer reasons why it should not be interpreted that way. I did not immediately claim he must be wrong, or that there cannot be a warming process going on."

    Is that correct? You said @369 (an unsupported assertion) "Clearly the models are badly flawed, and in science, when your models don't work, you discard them."

    Your position rests solely on this 'easy-interpretation-one-way' idea. As for a justification, this appears to involve two issues. There is the lack of warming issue which Mears does address but which you dismiss because you say it is based on a "belief" that warming is occurring, "not on reasoning." Accusing Mears' position here of depending on "belief" is wrong. He does address the idea of "errors in the fundamental model physics." And he gives his reasons for not giving them more credence. That is he knows of no "convincing evidence of model physics flaws." So which part of this is based on "belief" ?

    The other issue you raise is less easy to understand. You present it @389,373&376 as you first issue indicating some attached importance but your argument is not evident to me. Why should should the "ups&downs of the chart from about 1994 or so make a classic SPC chart that shows a stable process" have any relevance here? I have encountered folk insisting the temperture record has, for instance, all the signs of a random walk (which it doesn't), or perhaps the spin of the Earth's core (which requires some diligent cherry-picking). It's a pretty diverse set, all told. But resemblance to a "classic SPC chart" is a new one on me, and its relevance is not apparent. How so?

  33. Tom wrote: "Indeed, globally CO2 emissions did not rise in 2014. This has lead to some, probably premature, speculation that CO2 emissions have reached their peak. More probably they will tend to rise slowly over the coming decade,"

    There have been recent reports (e.g. SkyNews) that emissions for 2015 could be down from last year. Thus, we shouldn't take the possibility that they have peaked off the table. It is certainly possible that developing countries will push up emissions in upcoming years faster than developed countries draw them down, but there is also a chance that it will go the other way. How much China and India invest in renewables deployment will probably be the biggest determinant.

  34. What MarDivPhoto @376 said:

    "Sun and wind will never make up more than a fraction of the energy that modern life desires and demands."

    What the science says:

    a) Wind:

    "High power densities would be uninteresting if only a small amount of total power were available. However, wind power is roughly 100 times the power used by all human civilization.Total power dissipated in winds is about10^15 W. Total humanthermal power consumption is about10^13 W. Removing 1% of high-altitude winds’ available energy is not expected to have adverse environmental consequences."

    b) Solar:

    After adjustment for albedo and atmospheric absorption, the total power of surface falling solar energy is 161 (154-166) W/m^2:

    Of that, just 30% falls on land, giving a global landfalling solar power resource of 24,633 (23,562-25,398) x 10^12 Watts.  Of course, not all the land it falls on is suitable for solar power, and we will want to retain some solar energy for photosynthesis.  That leads to estimates of a total available solar resource of from 50 - 1,565 x 10^12 Watts, ie, 2.8 to 88 times the total anthropogenic energy use.  Those values represent in turn 0.2 to 6.6% of the total landfalling solar energy.  Even taking the lowest value, and at 10% efficiency of energy conversion, that represents just 2% of land area to power 2.8 times our current energy use.

    Quite patently from these figure, MDP's claim about the potential of solar and wind energy is absurd.  We must therefore look for a non-absurd interpretation.  The most likely of those is an assumption that solar and wind power technologies will not advance significantly from current capacities.  At best such an assumption is dubious.  However, in the discussion on solar and wind power, he advances as a solution increased research on fusion.  If he does not allow the possibility of technological advancement for solar and wind, he ought also not to allow that possibility for fusion.  Otherwise his argument comes down to special pleading.  Indeed, worse than that, current photovoltaic energy efficiencies are significantly better than the 10% I assumed for the land area calculation, and prototypes for turbines accessing jetstream winds are already flying - and whats more than nuclear, producing power at better returns than current pylon based wind power.  So he is not excluding the development of future technology at all, but excluding the deployment of below best practise current technology for solar and wind, while apealling to future fusion technology as an alternative.  Brazen, I believe is the best description for his argument.

  35. CBDunkerson @383, indeed.  I was not trying to indicate that we would not peak now, but that the data is insufficient for that call which is likely optimistic given known development goals for India and China.  I live in hope that the optimism is warranted.

  36. MarDivPhoto @376 objects to the description "denialist".  For the record, he introduced it twice before it was used by anybody else, and the single person that used it did not apply it to him.   It appears that his condition for staying for the debate he started is that we not only not call him a "denier" or "denialist", but that we pretend that nowhere in the blogosphere are there people suitably so called - not even in the 2nd law of thermodynamics thread.  If somebody cannot even admit that a common sort of behaviour can occur, it means, rather straightforwardly that they are in denial.  In this case it is not hard to see why.  As shown by me @378, 380 and 344 above, and by other commentors, MDP's arguments are radically disconnected from science.  Indeed, they are disconnected in such a way that the label "denier" seems well deserved as applied to them in particular.  It is no wonder then, that he launched his gish gallop then scurried away with his tail between his legs.  He must know in his heart he has no hope of defending his absurd claims.  

  37. "Tail between his legs" Really?  Being a combat veteran I have to laugh at such childish phrasings, but it simply reinforces what none of so many distinguished people seem to comprehend, that tolerance and courtesy used to be and should have remained central to reasoned discourse.

    The US gov't agency just announced we've had 117 months of lowered hurricane activity here, which is anecdotal, just as the spate of typhoons in the Orient is.  So whoever wishes to argue for their point of view can pick such data and go with it.

    Someone asked, reasonably, what data I would find really compelling about warming occurring.  The first answer would be if Dr. Mears' graph had shown a much clearer incline in temperatures for the last 15 years.  If people don't happen to understand what SPC statistical practice is, I'm sorry, it's too long to go into here, but it's been a critical tool in industries since the 1930s and was one of the major tools that enabled Japanese auto manufacturers to produce much higher quality autos in the 1970s than we were making here.  US industries have since re-adopted use of SPC broadly.

    The second answer would be when the retreat of both Artic and Antartic ice becomes pronounced and continues every years for at least 4-5 years.

    A third answer would be a very discernible change in coastlines throughout the world, with all of them moving inland.

    All that said, if and when a steady increase in global temperture becomes unmistakeable to all, then proving it is only the result of CO2 increase from 300 to 500 ppm is still a huge question.  As already stated, the models assume ppm changes in CO2 somehow bring on large changes in atmospheric humidity, but I know of no actual evidence of any such interaction.

    I can only smile when someone points out that total wind energy in the world is enormous.  So is tidal energy, so is solar energy.  Actually tapping it all is the challenge.  Will will build forests of wind turbines across most of the world, and watch the bird populations wither?  A firm two years ago wanted to build a solar farm in the vast Southwest desert of the USA.  They were stopped by an environmental group that filed a suit about the possible damage to the local ecology.

    India and China are still building more coal fired plants, so no matter what the recent data say about less CO2 generation, it is guaranteed to keep going up for decades to come.

    Worried about nuclear plants?  France gets 75% of its power from a network of standardized and very safe nuclear plants, and even recycles some forms of nuclear leftovers.  Thorium reactors are great technology that aren't being built.  The actual dangerous nuclear waste is a nonproblem, buried deep underground in tectonically stable regions is as safe as can be.  The Russians put it into dispersed liquid form and pump it down into dry oil well formations that were stable for millions of years, also a reasonable solution and it would sure be hard for anyone to get the stuff back from there.

    Should we try to use energy more efficiently? Absolutely, energy wastage is a scandal in too many places.  Should we explore as much practical use of hydro energy, solar energy, wind energy, and energy from the heat of the earth as possible?  Absolutely.  Should we recycle as much materials as possible, and get rid of the floating masses of plastic in the oceans, etc, replant forests, use water resources more carefully, etc.?  Absolutely, all these are not just good ideas but necessary ones for the future.  But should we jump into creating "carbon credit" exchanges that will make some brokers billionaires and raise the cost of living for everyone else?  I think not.

    Now I will apologize to all for thinking that perhaps I might be able to just introduce some contrasting thoughts about both science and how people, scientists especially, should be able to deal with each other.  I should have realized right away that this forum is solely for people whose minds are made up very firmly already, and that the seemingly beloved practice of denigrating anyone not in the group by the deliberately negative term "denialist" (a term directly relating to true nefarious denial of horrific historical events by the Nazis) demonstrates a sad frame of mind that truly reasonable, courteous people would avoid.

    In five years, or ten, or maybe 15, the facts will reveal themselves.  Hopefully there won't be extreme warming after all, or if there is, we'll have been smart enough to prepare well for it. With that, I bid you adieu, and shake the dust of this place from my sandals.

  38. MarDivPhoto @387 "can only smile" at the fact that just 2% of land area (not global area) can provide 2.8 times our power needs at 10% efficiency (or 1% of wind energy provid all our needs) but can provide no counter-argument except the rhetorical "Actually tapping it all is the challenge" before suggesting we must "build forests of wind turbines across most of the world and watch the bird populations wither" when the specific proposal he is rejecting involves airbourne turbines at  4600 meters altitude in the jets stream (and hence above almost all bird strikes) and involves power densities such that would require much less than 2% of land area to provide all the power we need.

    This proves, if nothing else, that MDP's idea of scientific debate does not involve reading references.

    As that is the only counter argument of mine MDP even adresses, I will leave it at that, save to note that:

    1)  Scientific debate occurs in scientific journals not in blogs.  What occurs in blogs when you raise issues of science without becoming expert in the debate, without a comprehensive review of the literature, and the confident view that the great multitude of studies that do apply those rigours to their participation are wrong, is denial - not scientific debate.

    2)  It appears that leaving, "shaking the dust of your feet" is absolutely different to leaving with your tail between your legs, even though both involved leaving without properly responding to (or even properly reading and/or checking references of) the counter arguments that devestate their own.

    3)  Whatever MDP has been indulging in, it has no ressemblance to reasoned discourse, which of course requires critically looking at evidence, not just cherry picking tropes to confirm your prejudices.

  39. Though this is veering off topic, coming from a manufacturing background, I can promise MDP that some of us here actually do understand the statistical process control (SPC) methods used by Toyota. But, you have to remember the "C" means "control." SPC is method by which you identify when a process if drifting outside control limits so you can take action. This is completely different from, and immensely more simple than, the statistical processes used in climate research. There are certainly related elements but I've worked with SPC for a long time and I can tell you, climate scientists are operating on an entirely different level of sophistication.

  40. MDP: "Sun and wind will never make up more than a fraction of the energy that modern life desires and demands."

    True, but nearly meaningless. After all, 9999/10000 is "a fraction". Thus, so long as we generate any amount of energy by any means other than sun and wind, those two sources will remain "a fraction". Thus, all you have really said is that we will never get 100% of our power from those two sources. Which no one disputes.

    Your 'logic' on nuclear doesn't make much sense either. Given that nuclear costs are rising, and already higher than solar/wind, there isn't any economic reason to be 'jumping all over' the technology. Rather, it seems inevitable that nuclear power will continue to decline while solar and wind continue to grow. Even the IEA now projects solar and wind becoming dominant by 2050.

  41. I can only smile too, when I see MDP refering to MA Rodger's initial response as an "attack." Perhaps that is because I have formed my opinion about attacks from perusing WUWT or CA, where physical threats or calls to hang people were not unusual. In my early days at SkS, I also endured all sorts of verbal abuse, in comparison to which MA Rodger's remarks would be considered pleasant conversation.

    MDP is trying to use self rightneousness and indignation to distract from the following facts: his initial arguments were wrong, and ample evidence has been provided to show they were. His interpretation of Dr. Mears' point was also in error. Once evidence was provided, MDP tried to use rethorical talking points to dismiss it, none of which so far stands up to scrutiny.

    Ignoring all other temperature records and using only the satellite measurements to argue that warming is not happening is not a scientific way to look at the problem. The weight of the evidence indicates that the satellite measurements are to be considered with skepticism. I see no skeptical mindset from MDP toward them, while he is eager to dismiss all other sources that are far more reliable. Where is the scientific skepticism?

    He also attempted to argue beside the point with the nuclear thing. Rational people are not afraid of nuclear, they simply see how it is not practical on the necessary scale. Besides the waste aspect, the costs are enormous and the plants have limited life spans. These are not trivial problems. France is facing the very serious hurdle of aging nuclear power plants, while the next generation has shown to be 10 years behind schedule, billions of euros over budget and has not yet powered a light bulb. Some "experimental" technologies do way better than that.

    The only reasons mankind would have to not eradicate completely coal burning in the next 50 years are political. They have to do with how much influence the barons of the coal industry have on policy making, not with the physical realities.

    Plenty of unjustified self rightneousness and misplaced indignation, but nothing convincing for evidence and references.

  42. For those who missed it this SkS post described how wind and solar (with a few additions) can power the entire economy.  That is all power, not all electricity.  There are a lot of wind generators but most land is unaffected.  Bird life is not significantly affected.  The objections of MDP are addressed.

    As far as waiting another 5, 10 or 15 years, we already have.  The world finally came around and agreed to start action in Paris.  If you do not look for data and refuse to read what you are presented with you will never be convinced there is a need for action.

  43. Very true, Michael sweet.

    And let me add: Very well said, Philippe @391.   I have been attending SkS for a far shorter time than you ~ so please correct me if my observations are faulty ~ but in that time of mine, I have generally noted that all [posting] newcomers have been treated with welcome & respect, wherever they have raised questions / objections / problems in a skeptical way (a genuinely skeptically scientific way, I mean).

    And appropriately:  the polite "kid gloves" treatment is sometimes not used, on those new posters who angrily insist that 2+2=3 . . . and whose tone and/or statements show an arrogant Dunning-Krugerism ( or, where more intelligent than that, nevertheless exhibit a self-crippling Motivated Reasoning so severe that they can't/won't see the wood for the trees).

    The latter ones very often also exhibit a gigantic hubris or chutzpah . . . which might just be tolerable in an eminent scientist who is demonstrably & totally in the right . . . but which is a tiny bit tiresome otherwise, in the self-appointed Galileos who manage to be 99% in the wrong.   Doubtless the hubris/chutzpah is some sort of over-compensation for inner anxiety [having noticed that all other scientists are "driving the other way"].

  44. MDP said: Sun and wind will never make up more than a fraction of the energy that modern life desires and demands. Planes will only fly by jet engines, and electric cars, trucks, trains, all get their kilowatts from some form of enegy generation, which right now is mostly from burning things. Logically we should be jumping all over 4th generation nuclear plant designs and funding research into fusion hugely, but somehow most of the people who are enthusiastic about reducing CO2 output reject any such ideas.


    No one ever rejected nuclear power as a reality: it just isn't the solution to global warming. Nuclear Power exists because Nuclear Weapons exist.

    If you are suggesting Nuclear Power is the solution to global warming then you are in effect suggesting the legitimacy of a pseudo-plutonium economy which has already been rejected globally a very long time ago.

    Don't tell me you want to mine moon-rock for fusion, btw: that wasn't even laughed at globally by youtube!!

  45. There has certainly not been a pause in US temperatures.

    Considering 1995-99 as the base (zero) period:

    The period 2000 to 2009 was 0.16 degrees C above zero.

    The period 2010 to May 2015 is 0.33 degrees C above zero.

    See this video showing how the changes from the 1990s to the 2000s were distributed across the US:

    US Temperature Comparison 2000s vs 1990s

  46. Deniers have been cherry picking both the starting date (the 1997/8 el Nino) and the data set (the RSS satellite data).  

    The RSS satellite data said there was a cooling trend if you start with 1998 data.  LINK

    There was a warming trend if you picked 2000 as the starting date instead of 1998.  LINK

    As of November 2016, there is a warming trend, even if you cherry pick 1998 as your starting date.  LINK


    [RH] Shortened links.

  47. Here it says that 2015, 2014, 2010, and 2005 were hotter than 1998. But weren't 2013, 2009, and 2007 all hotter than 1998 as well?

    That's what I determined after averaging these two data sets:

    NASA land-ocean temperature data

    NOAA land-ocean temperature data

    (even though they use different bases for the abnormalities, we can still determine the relative ranks of years).

  48. Good discussion. It would be helpfull to see here the data for 2014,2015, 2016, and 2017, to cinch the warming argument. An updated "escalator" would be dramatic.



    [JH] Your suggestions have been shared with the SkS author team.

  49. Recommended supplemental reading:

    Missing Arctic temperature data, not Mother Nature, created the seeming slowdown of global warming from 1998 to 2012, according to a new study in the journal Nature Climate Change.

    A University of Alaska Fairbanks professor and his colleagues in China constructed the first data set of surface temperatures from across the world that significantly improves representation of the Arctic during the "global warming hiatus."

    Xiangdong Zhang, an atmospheric scientist with UAF's International Arctic Research Center, said he collaborated with colleagues at Tsinghua University in Beijing and Chinese agencies studying Arctic warming to analyze temperature data collected from buoys drifting in the Arctic Ocean.

    "We recalculated the average global temperatures from 1998-2012 and found that the rate of global warming had continued to rise at 0.112C per decade instead of slowing down to 0.05C per decade as previously thought," said Zhang.

    The new data also improved estimates of the global warming and the Arctic warming rate.

    Added Arctic data shows global warming didn't pause,, Nov 20, 2017

  50. I often find myself in discussions with contrarians about the supposed "hiatus" of AGW from 1998. I'm happy to have these discussions as it appears to me to be a dishonest statistical trick to claim the hiatus i.e. the random picking of 1998 as the starting point. If they pick any other year it doesn't seem like they can get the desired result, from their perspective. 

    One of the claims that is made is that the IPCC acknowledge that the hiatus occurred and they point to things like box 9.2 in the AR5 report that is titled "Climate Models and the Hiatus in Global Mean Surface Warming of the Past 15 Years". Although, again, I don't have an issue in what is written there, my question is, why do the IPCC reports refer to this period at all and why use the term hiatus when this doesn't really fit with what is said? It just seems strange that they should talk about a period starting with such an anomolous year. Is it just to address the hiatus claims?

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