Who What When Where
Nic Lewis, an unaffiliated self described climate scientist, and a journalist, Marcel Crok, also unaffiliated, are known climate science denialists. The two of them have an objection to the International Panel on Climate Change (IPCC) conclusions regarding an important thing called "Climate Sensitivity." Perhaps unable to get their work in the peer reviewed literature, the two of them wrote "a report" titled "OVERSENSITIVE: How the IPCC hid the good news on global warming," that is available here. They make a claim which is totally incorrect but if it was correct it would be important. But it's not. Either.
Imagine a Spherical Earth
Climate sensitivity is a term that refers to more than one thing, but the basic idea is this. If CO2 concentrations in the atmosphere were to double, how much would global surface temperatures rise? It is usually considered from a "baseline" of 280 parts per million (ppm), which is the pre-industrial level. We are currently at 400 ppm and we are heading for 560, the doubling, with little apparent serious effort (in my opinion) to curtail the rise. Climate sensitivity is expressed in degrees Celsius. So if some one says "climate sensitive is 2" than they mean that we can expect global surface temperatures to reach 2 degrees above baseline given 560 ppm of CO2 in the atmosphere.
Imagine a spherical earth. Imagine no water vapor in the atmosphere, and just to keep things simple, let's have only land surface and no ocean. But the amount of air and its overall composition minus the water vapor is like our actual earth. On this imaginary earth, climate sensitivity is about 1.2. That's apparently pretty easy to figure out because it is a matter of how CO2 operates as a greenhouse gas and how much energy the sun supplies, etc.
However, there could be negative and positive feedbacks that would make this work out differently. This would be things that either make some of the sun's energy have less of an effect or more of an effect. Aerosols (dust) in the atmosphere, such as volcanic dust, can reflect sunlight away before it hits the earth's surface, so it will have less of a contribution to heating the planet (which sunlight mainly does at the surface where it converts to infrared radiation). Ice and snow also reflect sunlight away (that's called albedo). Water vapor in the atmosphere will generally act like a greenhouse gas and cause more heat by, to oversimplify a bit, interfering with the process of infrared heat leaving the atmosphere. Increased CO2 ultimately leads to more water vapor in the atmosphere, thus significantly amplifying warming. Warming can cause the release of methane into the atmosphere, another greenhouse gas, which in turn causes more warming until it oxidizes into CO2 and water. Water vapor can also get organized as clouds distributed in such a way as to add to albedo, reflecting away sunlight and decreasing warming.
With all these (and other) effects tugging this way and that on the temperature of the earth's surface (by which we mean the atmosphere and the upper layer of the seas), how is one to figure out what actual climate sensitivity is?
Well, it is hard, and there has been a lot of work on it. There are papers coming out all the time on this topic. The IPCC spent a lot of effort on it. And, there are two answers to the question "what is the sensitivity of the climate?"
(Before giving you the answers, I want to point something out that is very important. The Earth's surface does not warm up instantly as CO2 is added. It takes time. In fact, the changes that happen after CO2 is added to the atmosphere will continue for something like thousands of years. But the initial change, which involves the air heating up and weather systems changing and all that, would be observable over decades and reach a short term level of some stability in less time, measured in many decades or centuries. So there are two "climate sensitivities," long term equilibrium and transient, the latter being what is generally talked about, with the idea of a mutli-decade time scale. So, the question we are asking is what will the earth be like at the end of the century, given a doubling of CO2 in the atmosphere?)
So, back to the answers. One answer is the simple answer, and it is 3. This is the number that climate scientists seem to settle on when you hold them down and say "shut up with the mumbo jumbo, just give me a number." The other answer is about 1.5 to 4.5 but possibly higher at the higher end.
Some who wish to minimize the importance of climate change will say things like "1.5. That's a small number, what are you worried about?" Those people are boneheaded idiots and they are hoping you are too. Is 1.5 a small number? A large number? It depends. If I take 1.5 pennies from you it is a small number. If I kill you 1.5 times, it is a large number. Suffice it to say that 1.5 is a big enough number that we should be worried about it. Also, it is a low ball estimate of climate sensitivity. Almost nobody believes it. By one reckoning, there is something like a 5% chance that the sensitivity is actually around 6. Holy crap. That would probably melt almost every single drop of glacial ice on the planet and the map of the United States would look like this, in a couple/few centuries:
It would matter if there was a 20% chance that this is the map of the US your great grand children get to live with. They would actually have to remove stars from the US flag. If there is a US.
Below I supply a list of web pages you can check out to learn all about climate sensitivity.
But what about this report? Well, it's a doozy. First, it has a forward extolling the virtues of Lewis and Crok. That's nice. But the foreword is written by Climate Science Denialist Judith Curry. That does not bode well. Following this, the report is mainly a journey through a cherry orchard.
The adventures of Lewis and Crok
The report cherry picks a subset of scientific results that show lower sensitivity estimates and does a poor job of ruling out the other results that give higher estimates. They criticize the IPCC report, which summarized sensitivity studies, for leaving out the "good news" that climate sensitivity is actually very very low, by reporting a wide range of research indicating that it is not low. In other words, and I know this seems confusing but I think this is the point, Lewis and Crok are saying that the IPCC report is wrong because it reported all of the relevant scientific findings rather than just the ones Lewis and Crok would like to have seen noted.
DOES THE IPCC NOT KNOW ABOUT CHERRY PICKING YOU MAY ASK???
Sorry for shouting.
The authors suggest that the teams of scientists working on the IPCC report did not understand basic statistics, and that this contributed to their alleged overestimate of climate sensitivity. That part made me laugh.
Lewis and Crok put a lot of weight on what they term the observational record, which as you might guess if you have been following the denialist's literature is one of the best places to pick cherries. Also, astonishingly and, really, laughably, they rely on Lewis' prior publications suggesting low ball estimates of climate sensitivity. Yes, some guys have been pushing a particular scientifically difficult to support position; the world's scientists in a major international effort produced a summary of countless hours of research and dozens of peer reviewed papers that disagree with those guys; those guys write a report about how what they've been saying all along, which differs with the established science, must be right because they've been saying it all along!
Yes, that's about what this report amounts to. It's a bunch of hooey.
For further reading on climate sensitivity I recommend the following:
Other posts of interest:
- How to get rid of spiders in your house
- Why is your poop green?
- How many cells are there in the human body?
- Is there really a plot hole in Harry Potter Goblet of Fire?
- How long is a human generation?
- Is blog ever really blue?
- How to not get caught plagiarizing
- The origin of the domestic chicken
- What are the three necessary and sufficient conditions of Natural Selection?
- How do I get rid of foot fungus?
- Which is better, Tap Water or Bottled Water?
- Has Global Warming stopped?
Also of interest: In Search of Sungudogo: A novel of adventure and mystery, which is also an alternative history of the Skeptics Movement.
Nice post! Can you link to the reckoning that puts a 5% chance of sensitivity at 6?? Also certain people tell me that climate chane won't be that bad because the IPCC scenarios don't take into account peak oil. I would be very interested in your thoughts on that.
That is discussed in the Skeptical Science post. Peak coal is probably more important than peak oil, and that's in a thousand years from now or so. Plus, if we exploit the tar sands, etc., that puts peak oil out into the future by about one Saudi Arabia.
Who funded their work? A Koch bros. front group?
The characterisation of Nic Lewis as a denialist is rather unfair and lazy, especially since he *has* published in the peer reviewed literature.
(Of course, that doesn't mean he is right, e.g. see here for some criticisms of his analysis http://julesandjames.blogspot.co.uk/2013/02/a-sensitive-matter.html)
Of course if he now thinks he has a review of available estimates that favours lower estimates it would be better to publish that in the peer reviewed literature too.
The portrayal of lowER estimates as "low" (a subjective assessment) also seems rather flimsy to me.
I suppose you could call that report "The Lewis and Crok Exposition".
CurrentCO2 increase = 40%.
Temp rise = 0.85C, and continuing.
Ergo, any estimate below 2C is utter bollocks, no?
This post is better than good: clear, pedagogic, deservedly disrespectful, and with suggestions for further reading.
I do, however, find this comment problematic:
Greg Laden #2
“Peak coal is probably more important than peak oil, and that’s in a thousand years from now or so.”
Where do you get your thousand year figure from? American coal has probably already peaked, the quality of the coal mined is diminishing, the EROI is getting lower, and mining costs are getting higher. Moreover, if the coal industry is forced to pay for its externalities, it would soon become uneconomic.
According to Wikipedia, “China has 48 years worth of reserves. However, others suggest that China has enough coal to sustain its economic growth for a century or more even though demand is currently outpacing production.”
In addition, China's use of coal has already resulted in extreme air, water and soil pollution, reduced life expectancy and increasing social costs.
Then there's the water-energy nexus, which will greatly influence China's ability to exploit the reserves it has:
““Water shortages will severely limit thermal power capacity additions,” said Charles Yonts, head of sustainable research at brokerage CLSA Asia-Pacific Markets in Hong Kong. “You can’t reconcile targets for coal production in, say, Shanxi province and Inner Mongolia with their water targets.”
Coal industries and power stations use as much as 17 percent of China’s water, and almost all of the collieries are in the vast energy basin in the north that is also one of the country’s driest regions. By 2020 the government plans to boost coal- fired power by twice the total generating capacity of India.
About half of China’s rivers have dried up since 1990 and those that remain are mostly contaminated. Without enough water, coal can’t be mined, new power stations can’t run and the economy can’t grow. At least 80 percent of the nation’s coal comes from regions where the United Nations says water supplies are either “stressed” or in “absolute scarcity.”
“In order to sustain its rapid development, China needs a lot of water. It can only build as many cities as it can supply with clean water. And the country’s water supply is precariously limited: The Middle Kingdom is home to 20 percent of world’s population, but just 7 percent of its available freshwater resources. Rapid urbanization is quickly increasing demand for fresh water, while climate change threatens to further reduce availability.
Wang Rusong, an expert in urban ecosystems at the Chinese Academy of Sciences and an environmental advisor to Beijing’s mayor, told me when I visited his offices in May that China’s most worrisome environmental challenge is not what it has too much of — pollution, sewage, carbon emissions, etc. — but what it doesn’t have enough of: “The limiting factor in Beijing’s development is water,” he said. And Beijing is hardly alone.”
Philip, My thousand year comment was made up. I'll read your comment later when I get a chance. I'm pretty sure there is a lot more coal than oil, though. Like oil it is spotty in its distribution.
Of course there is always methane from the bottom of the sea.
Frank, I may be missing something, but how does his having some pubs make my characterization either unfair or lazy? Especially the lazy part, I'm not getting? Just curious.
idunno@7: A 40% increase is about halfway, logarithmically speaking (and that's how climate sensitivity works), to a doubling. So a rise of 0.85C so far implies a lower bound of 1.7 on the climate sensitivity. It probably is higher, because we haven't had (and likely won't have) time to come to an equilibrium at this level. But you are correct that a sensitivity as low as 1.5 is pretty much ruled out.
Where'd you get the sea level map? That looks much worse than the popular one from NatGeo a few months ago...http://thinkprogress.org/climate/2013/11/10/2908741/national-geographic…
Eric, yeah, you'd have to add some decades to reach equilibirum.
I made the sea level map. It does look worse than National Geo's because they made the assumption that a given rise of sea level would cause the sea to move the corresponding topographic line above sea level. That would apply in very few places,such as the coasts of Maine and the Maritimes, where the shore is hard rock. In places like the Gulf Coast and Florida, the sea would rapidly transgress across the landscape via erosion. To make it simple, since most of the coast would erode like this, I simply rounded up the number to the next highest unit in the available topo data that I had. Can't remember the exact amount but it was several feet. Generally speaking the strandline along the ocean is backed with a sea cliff of from a few feet to several feet high, so this seemed reasonable.
Any method of estimating this from large scale topographic data is going to be a very rough approximation. You would actually need to compile a lot of information and do numerous local surveys to get a really good estimate.
Here's my post on it:
Notice the graphic on top as well, which is by NOAA.
I don't know why I continue to frustrate myself by reading articles like this...it's like a train wreck and I just can't look away. Not that I dislike or disagree with the information...it is all very pertinent but it seems no one ever listens and we never seem to learn. We continue to talk in circles and no one ever comes up with a solution. That's because we keep waiting for "big brother" to solve it for us when to me ( and really I'm no one special, not a fancy scientist, or head of some research group. I'm just regular Joe Schmo trying to do the best I can) the answer is clear. So simple really that everyone looks right past it. WE...you, me, your Neighbour the guy down the street that let's his dog shit on your lawn, we are all responsible. Humans seem to have forgotten that we are part of this world and need to live in balance with it, not try to control it and certainly not waste what we've been given. Over consumption is going to be the death of us all. Over consumption of everything...we're like locusts eating everything in our path and blaming everything, anything else we can think of except for the real culprit...You and me. Change starts with each one of us, everyday, and the choices we make. Don't we teach our children to "make good choices" well let's start by making good choices. Stop over comsuption. Stop over eating, stop burning so much fossil fuels, stop buying clothes you don't need, stop buying the latest, greatest new toy every 6 months. We think we have no control it we do we just need to exercise it. Stop spending your hard earned money on stuff you don't need. Gas prices too high...stop buying it. There is always another way...so don't tell me you can't live without all of life's modern conviences because you can...you just have to decide that you love yourself, your children and your grandchildren more than all that needless stuff and to not want to leave the legacy of a crippled world that has spun of its rockers.
"Frank, I may be missing something, but how does his having some pubs make my characterization either unfair or lazy? Especially the lazy part, I’m not getting? Just curious."
Well, people are always criticising denialists for not making their arguments in the literature. And that's mostly true but not of this guy. Given that he has actually done the hard yakka to get something into a journal, it seems unfair to me to then turn around and say "oh, you did that? Well you're a denialist so we weren't going to listen anyway".
Another reason I think it's unfair is that as far as I am aware this guy has been polite, not that this should really matter but it should help. There is of course the by now routine assumption of bad faith in this new document ( the IPCC cannot just disagree, they have to have "hid" something) but it is not just some full bore denialist going "Algore is fat LOL".
And it's not just "some pubs" too - his peer reviewed stuff is directly relevant to the topic here. He's got an estimate of climate sensitivity past peer review. Doesn't make it right, but it deserves a bit more than a hand wave.
The reason I used the word lazy is because it's too easy to say every dissenting voice is a 'denialist' and avoids dealing with the better arguments.
Just a small point, but logically how can you kill anyone 1.5 times?
Perhaps others have categorized denialists as non published but not me. Hell, the forward of this report is written by a climate scientist who is published and is still a denialist.
I'm sitting here looking at my four year old son and thinking, "who is this guy who is asking me to be fucking polite to climate science denialists?"
So, there you go. I'm not lazy and I have no need to be "fair" to these people. This is not a "fair" thing.
Orson, I know, it almost seems like it wouldn't be fair.
There is a built in lag from rising CO2 levels to an increases in temperature caused by heat going into the oceans. Climate change is slow moving and the delay is estimated at around forty years. This means that we are having weather from the CO2 of 1970. Clearly there is a long way to go and if we stopped burning coal tomorrow it will be 2050 before we get the weather from the CO2 of today.
This report saying that he has thought of something to do with sensitivity that the IPCC has not thought of is rubbish and only published so that Fox News and a few others can quote it.
I have never heard of a "science communicator"?
how can you kill anyone 1.5 times
It's a way of saying that while they're being killed it will hurt like hell and they'll wish for death.
Dave Werth: I suppose you could call that report “The Lewis and Crok Exposition”.
Or you could just call it a crock. Which is unkind, but accurate as far as I can tell.
There are two aspects to this paper, it seems to me. The first is the question of scientific validity. With respect to that, it would be good if it had been published in a peer-reviewed journal. There it would be subject to rigorous assessment by mainstream scientists. Contrary to belief in certain quarters, scientists respect valid data. If Lewis and Crok had come up with some, they would get credit (although perhaps not immediately.)
The second aspect is the question of ideological bias. This is something which the Global Warming Policy Foundation, publisher of this paper, has consistently demonstrated. It opposes proposed actions to mitigate the effects of climate change, and seeks to forestall them by any means, including obfuscation of climate science.
All that said, nothing precludes a paper published by the GWPF exposing some new evidence that actually does show climate sensitivity is less than previously supposed. And as I said, if Lewis and Crok have done that, they will be recognized.
But I don't think they have. I come to that conclusion merely by reading the subtitle of their paper: "How the IPCC hid the good news on global warming." No scientists with the real, revolutionary data in hand would need to suggest a conspiracy to hide that data; they would simply present it and let things get sorted out. (After which, I frequently point out, they would be sorta rich and famous.)
That subtitle is, in short, a very good indication that their paper is blowing smoke. Perusing its 44 pages and explaining its faults is valuable, and I thank Greg for doing so. But part of the denialist strategy is to waste opponents' time, and any rule of thumb that cuts that short is IMO a good thing.
Lewis and Crok are clearly not "deniers" in that they don't deny AGW, but claim the climate is less sensitive to CO2 forcing than many believe.
You want to critique their article then great, but you sap your own credibility with the name calling.
They're not science deniers, but they are advocating for a lower climate sensitivity. The climate sensitivity scales to the amount of fear that any right-thinking citizen should feel, kind of like the terror alert color code. Saying that it's low means that they are saying that right-thinkers should not be so worried. This is why they deny reality. We should all be very afraid and only a denier would deny that.
They also used a classic set of denialist tactics, focusing on the hiatus as the source of understanding of climate, and cherry picking results, focusing on less reliable ones and ignoring more reliable ones.
Ask yourself, why would any real scientist not welcome a new or dissenting theory? Real scientists want to find the truth and are eager to test each hypothesis if there's any chance it might be proven. We haven't seen this kind of puritanical fervor promoting "climate change" since the Catholic church suppressed Galileo and Copernicus. When you see terms like "denialist" or kook, or "funded by the right," ask yourself where this is coming from. Is it science? Or is it a political agenda?
Dear "Sam Smith" from Texas.
There is plenty of dissent and alternative theorizing in real science. But then there is also the fake science, the non-science that does have a political or economic (or just plain kooky) agenda. The latter is what denialists do.
I know you think that one or a few people who get it totally wrong and are largely ignorant of the science must be brilliant and insightful like Galileo, but that is not actually how it works. That is not how Galileo did it, and it is not how you get to do it.
How is CO2 the cause of temp changes when historically CO2 levels has have always lagged behind the temp changes?
Good question. I'm not going to assume you are not one of those pesky science deniers pretending to ask an innocent looking question until proven otherwise, but I'll address this.
It is true that if a forcing other than CO2 raises or lowers temperatures, CO2 amounts follow, because of the way the Carbon cycle works. That is a separate effect than adding CO2 to the atmosphere, which then raises the heat. So you are talking about both different systems and different scales of change.
You can read about it here: http://www.skepticalscience.com/co2-lags-temperature.htm