Lovelock misses Trenberth's point.
Background: Stewart Brand tells us that James Lovelock has changed his views on global warming because of a paper published in Science written by Dr. Kevin Trenberth. Brand says Lovelock is saying some fairly extraordinary things for a man who was up until recently telling everyone that a catastrophic global warming was irreversible and there was nothing to do except try and enjoy life until the end came. E.g. Lovelock is now talking as if global warming has slowed mysteriously or even stopped: “we do not know when the heat will turn on”.
Lovelock is also, as he says, daring “to consort with skeptics”, i.e. the author of The Climate Caper Garth Paltridge, but that is for another post.
What I will discuss here is Trenberth’s research and why it seems clear that Lovelock has misunderstood him. What follows is almost identical to the text of an email I sent to Brand:
The paper Lovelock refers to is “Tracking Earth’s Energy” [1] (I’ll henceforth call it Trenberth 2010). This paper had to be short: it was a Perspectives piece. When Trenberth is through discussing ‘energy tracking’ in Trenberth 2010 he refers readers to a more detailed paper he published the previous year entitled “An imperative for climate change planning: tracking Earth's global energy” [2], I’ll talk about both. (I’ll call the earlier paper Trenberth 2009)
You understand Trenberth is eminent. He’s been a lead author on the science assessment for the last three IPCC reports. Lovelock doesn’t seem to understand what Trenberth is talking about.
When the deniers were trumpeting that the IPCC was corrupt at the height of “climategate”, one “smoking gun” they were waving around was a sentence from a Trenberth email. They claimed it meant Trenberth privately admits there is no evidence for global warming. Here’s the big quote:
"The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't."
Trenberth posted an online statement in response. Here’s part of it. This also explains why he wrote Trenberth 2009 and Trenberth 2010:
“It is amazing to see this particular quote lambasted so often. It stems from a paper I published this year bemoaning our inability to effectively monitor the energy flows associated with short-term climate variability. It is quite clear from the paper that I was not questioning the link between anthropogenic greenhouse gas emissions and warming, or even suggesting that recent temperatures are unusual in the context of short-term natural variability.”
The recently completed ARGO float system is now providing global ocean temperature and other data down to 2000m. The GRACE satellite system has been observing things like ice sheets as they melt for some time. The CERES system allows a calculation of how much energy is accumulating in the entire planetary system. And there has been satellite altimetry since 1992 that is allowing millimeter precision measurement of sea level. This is just a partial list. Trenberth is convinced that climate scientists ought to be able to “obtain closure of the energy budget”, i.e. explain a lot more than they have been able to in the past. But they can’t do it just yet. Note the word “bemoaning”. He’s frustrated.
But all this doesn’t mean scientists can now explain less than they once could.
He didn’t write the paper to announce global warming had slowed or stopped. It hasn’t.
I asked Trenberth (in November 2010) what he would say now. He hasn’t changed his views. He emailed:
“the anthropogenic global warming signature is not large enough to overwhelm natural variability and so the trend from increased GHGs is only clear on time scales of 25 or more years. We used 25 years in Chapter 3 of IPCC as the lowest trend we provided that was meaningful…. So any pause in sfc T increase from 2000 to 2008 is not unexpected and the first 8 months of this year were the warmest on record and have restored the upward trend. So there is no evidence of a reduction in trend”
Hansen has a paper “in press”, published online, “Global Surface Temperature Change”[3] that says the same thing:
“Of course it is possible to find almost any trend for a limited period via judicious choice of start and end dates of a data set that has high temporal resolution, but that is not a meaningful exercise. Even a more moderate assessment, "the trend in global surface temperature has been nearly flat since the late 1990s despite continuing increases in the forcing due to the sum of the well-mixed greenhouse gases" [ Solomon et al., 2009 [4] ], is not supported by our data. On the contrary, we conclude that there has been no reduction in the global warming trend of 0.15-0.20°C/decade that began in the late 1970s.”[5]
It seems some people think about “the planet” heating up or not, “global warming continuing or not”, and the “temperature”, i.e. the average global surface temperature record going up or down, as if they were all the same thing. They aren’t. “The planet” is the entire system, which includes the oceans, the ice, the rocks, the atmosphere near the Earth’s surface, and the entire atmosphere. “Global warming” can refer to either the surface temperature record or the entire system, depending on who is using the term.
When Trenberth uses the word “temperature” in the quotes above, or when Hansen says “global warming trend”, they are referring to the average global surface temperature record. When Lovelock talks about “something slowing the rate of global warming” he is also talking about the surface record. The fact that he speculates about where in the rest of the system the “missing energy” could be shows that. But his “sense of alarm” stemmed from what he thought the whole system was doing. Lovelock seems to understand that the whole system is still heating up. I.e., his email to you says: “Earth is warming as expected….” What reason could he therefore have to “soften” his assessment of how dangerous climate change is?
There is no reasonable doubt left that the whole system is continuing to heat up. Trenberth 2009 says: “global warming is unequivocally happening”. The National Academy states: “the core phenomenon, scientific questions, and hypotheses have been examined thoroughly and have stood firm in the face of serious scientific debate and careful evaluation of alternative explanations” [6].
The long term average global surface temperature trend, as Trenberth and Hansen unequivocally assert, never stopped rising.
What seems clear is that you or Lovelock or both think “something unknown is slowing global warming”, you and/or him have “softened” your sense of alarm, and now you and Lovelock are touting the work of a quack “sensible skeptic”, Garth Paltridge.
Paltridge is not credible. He goes far beyond claiming there never was anything to be concerned about. He’s saying the people who say otherwise, i.e. the worldwide scientific establishment, are jeopardizing the reputation and enterprise of science itself with their corruption and shoddy work. This “sensible” man is telling us that the scientists who make up the IPCC are the worst thing that has happened to science in several hundred years. [7]
I can’t understand why you would describe this man as “sensible”. Have you actually read his book? I put some thoughts about Paltridge in a separate paper for you.
What do I think Trenberth’s research is about?
Trenberth wants to look at every squiggle in the global surface temperature chart and say he knows what is happening. He wants to be able to describe in real time where all the energy is and where all the accumulating new energy goes.
Trenberth 2009 listed many ways which could explain all or part of why is “the temperature not continuing to go up?” even as energy continued to accumulate in the planetary system. Trenberth wrote: “surely we have an adequate system” to verify which explanation is correct, as opposed to the “stock answer” which is “natural variability”. He was forced to conclude: “we do not”.
He appears to want to banish the phrase “natural variability” from climate discourse in the same way “here be dragons” was banished from maps. We won’t hear as much about “natural variability” when climate scientists know more.
Trenberth uses “missing energy” the way physicists do. When things don’t add up they know its time to go back to the drawing board.
Climatologists have never been able to fully explain what is happening to Earth’s climate. This is not news. Climatologists freely discuss significant uncertainties, even as they almost unanimously tell civilization it is getting far past time to act based on what is known.
Consider another of Trenberth’s recent papers: “The Ocean is Warming, Isn’t It?” [8] published in Nature one month after the appearance of Trenberth 2010. Part of the problem with moving climate science to the new level of understanding Trenberth wants to move it to is that the comprehensive ocean observations have only recently begun. The way Trenberth puts it: “observing systems to capitalize on these insights are in their infancy.”
He says: “revolutionary progress… has taken place in ocean observations….” He predicts that “…ocean heat content is likely to become a key indicator of climate change”. A recent best effort to depict the ocean heat content trend [9] looks like this:
Here is another graphic [10] way to look at heat in the ocean, based on IPCC data:
The ocean holds such a gigantic amount of heat compared to the atmosphere, it is the “dog” wagging the atmosphere “tail”.
Ocean currents moving relatively tiny amounts of ocean heat compared to what’s already in the ocean can have a big impact. A tiny amount of heat relative to what’s in the ocean is a very large amount of heat relative to what’s in the atmosphere.
Here’s an example set of pictures of ocean heat scientists can get these days. This set shows where heat is in the Pacific ocean as ENSO unfolds:
The ocean heat data (looking down into a slice of the ocean more than 600 feet deep) depicted here came from the TAO moored buoy system that was completed in 1994 to observe ENSO. The ARGO floats more recently deployed almost everywhere in the global ocean allow observations down to 2000m.
Almost all attention has, until now, focused on the average global surface temperature chart. Trenberth thinks this focus is about to move to or at least start to include where most of the heat actually is. Trenberth wants to know where all the heat is.
He is frustrated because the hour is getting late. As stated already Trenberth 2009 reiterated the IPCC AR4 conclusion: “global warming is unequivocally happening”. He writes of the “failure” by the governments of the world to so much as come up with a plan to deal with it. He brings up “disruption and loss of life” saying “to plan for and cope with the effects of climate change requires information on what is happening and why”.
Trenberth 2010 raises an additional concern by referencing Superfreakonomics. The pop economists who wrote that book aren’t the only ones discussing geoengineering as if it were an option that should be considered on its economic merits because it appears to be cheaper than attempting to stabilize the composition of the atmosphere. Although Trenberth’s scientific approach assumes that such understanding is possible, he asserts that “such proposals assume understanding” that we do not have.
The press release announcing Trenberth 2010 said this: “It is critical to track the buildup of energy in our climate system so that we can understand what is happening and predict our future”
Trenberth attached a one page “poster [11]” to his personal communication to me which describes work he has done since publication of Trenberth 2010: “We are exploring this in model runs and I attach a poster showing some preliminary results. The indications there are that the top-of-atmosphere shows warming is occurring at order 1W m-2, during decadal periods when no surface warming occurs. The upper ocean heat content also falters, some heat is between 250m and 700m but most of it below 700m in the ocean and it relates to Pacific decadal variability. Whether this applies in the real world or not remains to be seen and how it happens is not yet clear. But if it is right then indeed the heat is being sequestered and comes back to haunt us in future…. The missing energy does not stay missing for more than about 15 years in the runs we have looked at….”
Trenberth explained why things are “not yet clear”: “the observations are perhaps inadequate, the processing of them can certainly be improved, and the processes and where stuff happens is not understood.”
If an apparently flat-lined average global surface temperature short term trend lulled enough people into believing the planet was no longer heating up, the ultimate driver, the accumulated CO2 and other GHGs, just gets bigger and harder to deal with. The “gain” would be that our fool’s paradise where we pretend this is not happening or is not serious would continue on a bit longer. There would be a big loss: the reality of more damage than anyone would ever want to cope with will set in, we will wake up, and we will then discover that the “gain in time” allowed us to turn up the biggest planetary temperature control knob, CO2, even higher.
A new NOAA study (news report here) (abstract here) found enough heat moving into the deep ocean around Antarctica that the authors say if it were moving into the atmosphere at that rate (a physical impossibility) the atmosphere would be warming an extra 5 degrees F. per decade.
For another perspective on “missing energy” consider Hansen’s analysis.
Hansen has been calling attention to uncertainties in climate science and calling for more and better data for years but he uses different concepts. E.g. whereas Trenberth 2010 asks: “is the warming associated with the latest El Nino a manifestation of the missing energy reappearing?” Hansen points to the same El Nino and says this is heat in the planetary system that is “sloshing about”.
Hansen illustrated the effect of El Nino in his 2008 Bjerknes Lecture, [12] on page 4. This chart shows that the two average surface temperature charts depicted, global and low latitude, vary with the sign and strength of El Nino/La Nina a.k.a. ENSO.
Incidentally, you note that Hansen “deplores our lack of good data on aerosols” in your Afterword. This is true.
However, Hansen reiterated in 2008 during this Bjerknes lecture that he is actually more concerned about the oceans: “The only way we are going to figure this out is to get the right observations. First of all that means better observations of ocean heat content, including the deep ocean. Second, we must measure aerosols with the required accuracy….”
As Trenberth said on NPR just before Trenberth 2010 came out: “I suspect we’ll be able to put this together with a little bit more perspective and further analysis. But what this does is highlight some of the issues and send people back to the drawing board.” NPR interviewer Richard Harris summed up: “Trenberth and Willis agree that a few mild years have no effect on the long-term trend of global warming. But they still have things to learn about how our planet copes with the heat.”
In any case, what does refining our understanding at Trenberth’s level of detail have to do with debate about whether civilization should take climate change seriously and limit emissions of GHGs? There has been enough solid information to act for more than twenty years.
It was said in 1988 by many climatologists that 95% of their colleagues had come to the view it was time to tell civilization to take action. Consider the first paragraph of the final statement of the Changing Atmosphere conference held that year in Toronto. Almost 400 delegates from 40 countries, including some of the leading climatologists in the world, worked on the statement for 4 days. I was one of the delegates. This paragraph was not controversial.
“Humanity is conducting an unintended, uncontrolled, globally pervasive experiment whose ultimate consequences could be second only to a global nuclear war. The Earth’s atmosphere is being changed at an unprecedented rate by pollutants resulting from human activities, inefficient and wasteful fossil fuel use and the effects of rapid population growth in many regions. These changes represent a major threat to international security and are already having harmful consequences over many parts of the globe.”
You know many scientists now say things are bleak.
Ramanathan published recently saying that preventing “dangerous anthropogenic interference with the climate system”, the objective of the 1992 UNFCC convention that was signed by the first President Bush and ratified by the US Senate, is “most likely” not possible now. He bases his analysis on points not in dispute that appear in the IPCC AR4.
Everyone knows about Hansen. Hansen writes in “Target atmospheric CO2, Where should humanity aim?” that paleoclimate studies show that an ice free planet, i.e. 260 feet of sea level rise, may already be “in the pipeline” for our descendants unless we or they are successful in removing some CO2 from the atmosphere after stabilizing its composition. He notes that humans are moving fossil carbon into the atmosphere many hundreds to ten thousand times faster than natural forces did in the past.
There have always been uncertainties in the science, but it is not as uncertain as you seem to think. When you said in Vancouver, that there is a 1/6 (your Russian roulette analogy) possibility that climate may end up not changing at all because of feedbacks canceling each other out this goes against what Earth’s climate history, i.e. paleoclimate, has to tell us.
Paleoclimate data has all the feedbacks in. If you want to see the results of a “model” run that includes clouds, aerosols, GAIA, “unknown stabilizing factors” in climate dynamics, the kitchen sink, and whatever, look at paleoclimate.
When the level of CO2 goes up the planet warms.
How could turning up the biggest control knob of the climate change of the past at a rate hundreds to ten thousand times faster than any change of the past possibly result in a one in six chance of having no effect?
Dr. Richard Alley presented an overview of how the science of paleoclimate and CO2 has evolved into what is known now in his Bjerknes Lecture, (video here) and concluded:
“If higher CO2 warms, the Earth's climate history makes sense. If CO2 doesn't warm we have to explain why the physicists are stupid and we also have no way to explain what happened. And it’s really that simple. We don't have any plausible alternative to that at this point”.
The next chart shows that in terms of geological time, what is happening now is an instantaneous increase in CO2. CO2 is the blue line. The red line is planetary temperature over the last 420 thousand years. The high points of planetary temperature are interglacial periods, the lows are ice ages. Today is to the left, 420,000 years ago is to the right:
Similar data has been available since 1987. The CO2 accumulation since the industrial revolution began shows as the thicker blue line going straight up because the few hundred years it has taken is on a timeline of 420,000 years long.
I don’t know where people get the idea that dialing in even 350 ppm at this rate is “safe”, or that continuing on to 550 ppm and beyond might be “sensible”. I was calling for stabilization and return to the preindustrial 280 ppm CO2 as far back as 1988 [13]. Many with policy experience say it is already impossible to avoid hitting 450 ppm. Rowland believes civilization will experience what happens at 1000 ppm.
Every highest level national science organization on the planet is stating the science is solid enough that action must be taken now because lags in the climate system and the length of time it will take to reduce emissions mean time is quickly running out. [ e.g.: here is what the national science academy of every country in the G8, plus India, China, South Africa, Brazil, and Mexico, all signed. It was handed to every head of state attending the G8 meeting in Japan.]
Not one of these highest level science academies issued a retraction as a result of Trenberth’s paper, because of “climategate”, because Paltridge published a book, because a few mistakes were found in thousands of pages of IPCC reports, because many mainstream media journalists in the wake of “climategate” are saying they regret they didn’t engage ‘credible’ skeptics earlier, or for any other reason. Ralph Cicerone, President of the National Academy of Sciences in the US has stated that after all, “our understanding is undiminished”.
PS. You were saying in Vancouver that Lovelock believes GAIA stabilizes things after Earth loses its ability to support most people alive today. You say in your book: “Earth will be fine, no matter what; so will life”, which sounds similar to Lovelock’s view. Hopefully, this will prove to be true.
However, that view may prove to be a myth not supported by science: Hansen thinks whatever Lovelock means by GAIA can be killed. Hansen said, of GAIA, in his Bjerknes Lecture : “A nice idea, but it doesn’t work”. He said in his lecture that he thinks it is possible for the oceans to boil away and for Earth to never have life again. He isn’t saying his model predicts that: “Our model blows up before the oceans boil”.
What he does say: “…perhaps runaway conditions could occur with added forcing as small as 10 – 20 W/m2.” “There may have been times in the Earth’s history when CO2 was as high as 4000 ppm without causing a runaway greenhouse effect. But the solar irradiance was less at that time. What is different about the human made forcing is the rapidity at which we are increasing it, on the time scale of a century or a few centuries…. In my opinion, if we burn all the coal, there is a good chance…. If we also burn all the tar sands and tar shale… I think it is a dead certainty”.
He is concerned that the rapid buildup of CO2 will release the methane from clathrates.
The 420,000 year timeline looks like this if CO2 is drawn up to the 4000 ppm level Hansen is describing:
This is based on the same Vostok core data as the graphic above. The line going straight up is CO2 from the beginning of the industrial revolution to some time maybe 100 or 200 years from now if Hansen’s nightmare comes true.
Note this scale shows that relatively miniscule variations in CO2 caused transitions as large as the ice ages and interglacials.
“Sensible skeptics” would have us believe that nothing out of the ordinary will happen to that red line representing planetary surface temperature as a result of that blue line going straight up.
In the next graphic what I’m trying to show is that temperature follows CO2 up from zero ppm, then as CO2 ranges from about 180 to 280 ppm there are the ice ages and interglacial periods. I ask you the question as to what will happen as CO2 relatively instantly moves to 550 ppm. The horizontal red line is where physicists say the planet would be with no GHG in the atmosphere, i.e. minus 18 degrees C.
The “sensible skeptics” if Paltridge is an example, tell us this means nothing. CO2 has no relationship to planetary temperature, the physicists are stupid, the climatologists are corrupt morons who are the worst thing that has happened to science in several hundred years, feedbacks might cancel each other out, there was a Medieval Stupid Period, someone broke a Hockey Stick, the planetary system will magically cooperate because civilization can’t be bothered to deal with this, whatever the gibberish is, in any case, nothing much is going to happen.
One more point: Lovelock’s “sensible skeptic” Paltridge tells us, as his first argument in The Climate Caper, starting right from the first paragraph in Chapter 1, that when the IPCC was first created, it took an issue that “a lot of scientists” weren’t particularly worried about, i.e. who actually thought at the time (1988) that the “concern was already past its peak” and blew it up into a “semi-religious crusade” by “manipulating” the climate science issue “into the ultimate example of the politically correct” by acting as if the “science behind the issue” is “irrelevant”. Trenberth, as a three time IPCC lead author on the IPCC scientific assessment side is, therefore, one of these scientists.
Paltridge would have us believe Trenberth is a menace to the ongoing credibility of science itself as he continues on with his work.
How can Lovelock point to Paltridge and call him “sensible” while pointing to Trenberth for his insight? It is incredible that Lovelock thinks it is “amazing how tribal scientists are” as they reject him now that he is touting Paltridge.
[1] Trenberth, K. Tracking Earth’s Energy, Science, 16 April 2010 Vol 328 p 316-317
[2] Trenberth, K. An Imperative for climate change planning: tracking Earth’s global energy, Current Opinion in Environmental Sustainability 2009, 1:19-27
[3] Hansen, J., R. Ruedy, Mki. Sato, and K. Lo, 2010: Global surface temperature change. Rev. Geophys., in press, page 21
[4] Solomon, et. al. Contributions of Stratospheric Water Vapor to Decadal Changes in the Rate of Global Warming, Science, 5 March 2010, pp. 1219 - 1223
[5] Hansen, J., R. Ruedy, Mki. Sato, and K. Lo, 2010: Global surface temperature change. Rev. Geophys., in press, page 21
[6] Advancing the Science of Climate Change, The National Academies Press, Summary, page 1
[7] Garth Paltridge, The Climate Caper, Taylor Trade Publishing, 2010, page 10
[8] Kevin Trenberth, The ocean is warming, isn’t it?, Nature Vol 465 May 2010, page 304
[9] State of the Climate 2009, N.O.A.A., Report at a Glance: Highlights, page 4
[10] State of the Climate 2009, N.O.A.A., Report at a Glance: Highlights, page 4
[11] Meehl, Arblaster, Fasullo, Hu, and Trenberth, Decadal Variability of globally averaged surface air temperatures: Where does the heat go when the trend is flat? NCAR “poster” one page paper. Attached to personal communication to me.
[12] James Hansen, Climate Threat to the Planet: Implications for Energy Policy and Intergenerational Justice. Slides and notes for Bjerknes Lecture given Dec. 17 at the American Geophysical Union, San Francisco
[13] In political debate in British Columbia and Canada. I got the Green Party in B.C. to adopt this goal as written policy sometime in 1989.
No comments:
Post a Comment