What Motivates a Climate Skeptic?

Wed, 2011-04-06 07:05Chris Mooney
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What Motivates a Climate Skeptic?

I always like digging around in the academic literature for insights about today’s politicized science battles. Now that social scientists have begun to apply themselves to public fights over the hard sciences, I find that they have a great deal to offer. The latest exhibit: The work of Andrew J. Hoffman, Professor of Sustainable Enterprise at the University of Michigan. 

Hoffman is an “organizational theorist.” As such, he believes that “failing to attend to the deeper social and cultural forces within the climate conflict, and in particular the counter-movements that resist the dominant logic,” is a big mistake.

So he went and studied the “culture and discourse” of climate skeptics—which involved attending their conferences and events–and describes some of the preliminary results in a recent paper in Strategic Organization. As a result, Hoffman argues that three themes are dominant in the movement. And here’s where, to me, it gets really interesting.

1. Stealth Attack on Personal Freedom. Skeptics, write Hoffman, think concern over global warming just a ruse to curtail personal liberties—by increasing the power of government to interfere in the market. This of course carries over to a deep distrust of the U.N. At a climate skeptic conference, writes Hoffman, one presenter “went so far as to suggest that a binding international agreement on climate change would end with individuals being required to carry ‘carbon ration cards’ on their person.”

2. Free Marketeers. Relatedly, the skeptics have a “strong faith” in the free market. Renewable energy is distrusted because it needs to be subsidized. Huh—what do they think of fossil fuel subsidies, then? Hoffman does not discuss what seems to me one plausible outcome of this free market commitment: The belief that markets could not really create a problem like climate change, or if they do, markets also will solve it.

3. Distrust of Peer Review. To me, this was the most intriguing finding. Skeptics, write Hoffman, “argue that public funding of science in the post-Second World War era through organizations like the National Science Foundation (NSF) corrupted the scientific process.” Um, such funding also made us the world’s science superpower—but I digress. The point would seem to be that skeptics distrust all government, publicly funded science because they believe the peer review system has been corrupted and incestuous—after all, it’s not a free market system–and the “ClimateGate” brouhaha just served as a confirmation to them of this deeper distrust.

So if you’re one of those people who asks yourself, “how can they believe this stuff?” Well, that’s how.

What’s surprising to me is that none of this is, at base, scientific. It’s all about distrusting some kind of power associated with the government, while very much trusting other kinds of power that are unregulated.

In other words, it’s about how society—not the atmosphere—is organized.   



So climate change deniers are self-centered paranoid libertarians who are fundamentally indifferent to the actual environmental consequences. Or exploiters of the same.

Doesn't surprise me in the least.

When you wrote "how can they believe this stuff?", you meant the stuff they believe about climate change. But I wonder how they can believe the stuff Hoffman cites about why they believe the other stuff!

I think emotional motives drive deniers as much as the logical ones given above. I observed one prominent denier years before he became a denier. I suspect the following:

1. A strong desire for public attention. He had more news on less achievements than any other scientist.

2. A longing for missing respect. He is now said to be "esteemed" by the right wing.

3. A desire to prove other scientists wrong.

No, Hoffman's observations aren't necessarily "scientific," as in statistically significant empirical evidence. They are just his observations, from what I gather (having not read his paper). And all I can offer is that his three points sound very much like a family member of mine who is a denier. He's very smart, often skeptical, but also often not skeptical enough, and I think it is mostly emotional for him, though not the same as the 3 points Ginger laid out. Of course, he would deny that he is led by his emotions ever, as he gets angrier and more insulting...

To be the big fish they long to be, these people need to find an unusually small pond. :-)

What is odd is that what many libertarians take to be the free market's greatest strength -- namely, that through decentralization and coordination through the pricing system it effects a division of cognitive labor -- largely parallels what occurs within science. I remember one libertarian arguing a while back at Real Climate that you couldn't trust science that was government-funded if it might have political implications.

Ray Ladbury had summarized the fellow's view along these lines:

"Let me get this straight. We have temperature measurements that show each subsequent decade of the last 3 is warmer than the last, but you don't trust them because the data are processed by the government. We have satellite measurements showing we've lost 2 trillion tons of ice in the past 5 years, but you don't trust them because they're government satellites. We've got glaciers retreating the world over, but you don't trust those measurements because government scientists made them. We have a hundred and fifty years of climate science all of which supports anthropogenic causation of the current warming, but you don't trust all that work because some of the scientists worked for the government."

I responded by comparing it to the views of Young Earth Creationists who argue that the Earth is less than 10,000 years old and are willing to toss out all scientific knowledge to the contrary:

"Sounds about right — right down to your quantum mechanics, the absorption and emission of photons (Einstein was a patent clerk) by matter, the spectra, any inconvenient fact. All the studies, papers, scientists and sciences one vast conspiracy to hide the truth of his world view. Reminds me of some of the more extreme views I found among young earth creationists."

Later several people discussed how what scientific projects get funding is itself highly decentralized.

I continued along these lines:

"... another (albeit related) key problem is the decentralized nature of the process of scientific discovery. Those who determine what funding gets done won't know beforehand what will be discovered — and they wouldn’t be able to keep track of all of the interconnections which will be discovered by the vast number of independent and highly intelligent minds that are involved in this process. To do so would greatly exceed the intelligence of any central authority, whether it be an individual or committee."

Furthermore, I pointed out how this was closely related to what I take to be a central principle explaining the power of science:

"The justification for a conclusion supported by several independent lines of investigation is generally far greater than that which it receives from any given line of investigation considered in isolation.

The libertarian came back and quoted my words:

"...quantum mechanics, the absorption and emission of photons (Einstein was a patent clerk)...," then responded:

"(The above was by way of a suggestion that political funding would then equally colour these issues.)

"No, since – unlike with AGW – there is no obvious political spin to be put on them."

To this I responded:

"The trouble is that what I am describing is the physical basis for the greenhouse effect.

"The greenhouse effect is the result of molecules being stimulated into vibrational, rotational and rovibrational states of excitation. This may be the result of the absorption of photons or molecular collisions in which they gain energy. De-excitation occurs either through either molecular collisions in which they lose energy or through the emission of photons.

"The absorption of photons results in the warming of the atmosphere and their emission results in the cooling of the atmosphere. Absorption of thermal radiation cools the thermal spectra of the earth as seen from space, radiation emitted by de-excitation is what results in the further warming of the surface, and the surface continues to warm until the rate at which energy is radiated from the earth’s climate system (given the increased opacity of the atmosphere to longwave radiation) is equal to the rate at which energy enters it."

Then I continued by explaining the essentially indivisible nature of science:

"You see, the trouble is you can't separate science in that fashion.

"The basis in physics for explaining the greenhouse effect is essentially the same as that for describing photovoltaic devices, or that which Einstein used to suggest the possibility of lasers. The same principles form the basis for our ability to perform calculations in chemistry and biochemistry at the quantum level. It is how we are able to understand and predict the behavior of tunnel diodes.

"It is the same as what goes into infrared detection used in the military by fighter jets..."

I then concluded,

"Now since you have helped me illustrate this principle, clearly you are deeply involved in the conspiracy, and as such there are only two questions that still remain to be answered.

"First, as one of the conspirators, are you using your real name or a pseudonym?

"Second, if it is the latter, what name should I write the check out to?"

There are deep parallels between Hayek's argument for a decentralized economy and the argument for the power of the division of cognitive labor in the scientific enterprise. And I am more than a little surprised libertarians typically have so much difficulty seeing this -- and what it implies regarding climate science.

You guys are very right. People are *emotionally connected* to the premises above, and then “reason” on that basis.

1/. Al Gore
2/. Lack of empirical evidence
3/. Personal observation
4/. Common sense
5/. Political interference
6/. Tax occasion
7/. Offers of outlandish incentives
8/. CO2 called a “POLUTANT”(just can’t get my head around that one)
9/. Wow. I've not even started!!!!

Stop! You had me at Al Gore...

Yeah, It was the Nobel Prize that was the game changer for me.

Why, of course it was!

The skepticism comes from the apocalyptic scenarios continually laid out by AGW proponents, none of which have come true to date (though they should have).

There is also a doubt about the ability of scientists to accurately predict climate a hundred years from now. Scientists have never claimed this ability before and rightly, people are going to ask questions. Since they are not answered, we become even more skeptical.

Intellectual fig leaf, meet straw man.

paul s wrote, "The skepticism comes from the apocalyptic scenarios continually laid out by AGW proponents, none of which have come true to date (though they should have)."

What apocalyptic scenarios are you talking about that should have come true to date? Do you have a reference for that?

I don't know about apocalyptic, but people are noticing an increase in the global average annual temperature that is roughly 0.15 deg;C per decade so far. And it is expected to accelerate over the course of the century.

The reason for the rise in temperature? I go into the physics (albeit at a largely informal level) behind the greenhouse effect at my home page.

There is a video showing the absorption of thermal radiation by carbon dioxide. You will see the image of a candle as seen by an infrared camera through a tube being filled with carbon dioxide. The burning of the candle remains strong, but the image as seen by the infrared camera slowly goes out.

There is a graph showing the spectra of incoming solar radiation and outgoing thermal radiation. Both match up with the blackbody spectra -- except with bites taken out by the greenhouse gases given their absorption spectra. You can see those below. And through satellite measurements we have actually been able to measure how outgoing has changed since the 1980s and it is as predicted given the increased levels of green.

You can see the structure of the carbon dioxide molecule, how it changes due to the different modes of vibration in accordance with the principles of quantum mechanics, what parts of its absorption spectra line up with those modes. The absorption spectra associated with those modes. The asymmetric stretching mode centered at 4.3 μm is at too short and energetic a wavelength to affect the outgoing thermal radiation but the bending mode centered at 15.00 μm is just right.

I also give graphs of the absorption spectra around 15.00 μm as you increase the concentration of carbon dioxide. You can see how larger parts of the spectrum get absorbed as you increase concentrations to more than 100x pre-industrial.

I show satellite images of the earth in July 2003 as taken by the AIRS (the Atmospheric InfraRed Sounder) aboard the Aqua satellite. You can see for example the plumes of carbon dioxide rising from the heavily populated and industrialized east and west coasts of the United States. The reason why the satellite is able to see the carbon dioxide is because it absorbs thermal radiation in specific parts of the spectra. In essence you are seeing the greenhouse effect in action. I also have an image of the thermal radiation coming up through the atmosphere at other wavelengths specific to water vapor.

If you decrease the rate at which energy escapes the atmosphere but keep the rate at which energy enters the atmosphere the same the amount of thermal energy in the system has got to increase -- which means that things have got to heat up. They have been -- at roughly 0.15 °C per decade. Roughly what is predicted -- although it is expected to increase over the rest of this century.

Increase the temperature and you increase the humidity of saturation. Increasing the surface temperature over the ocean by 1°C should increase the humidity of saturation and thus the absolute humidity by 8 percent. We are seeing that. Increasing the temperature by by 10°C will roughly double the humidity of saturation and consequently absolute humidity over the water's surface. We know this from experiments under a wide variety of conditions. And water vapor is a greenhouse gas.

Increase the temperature and you increase the rate of evaporation. Increase the rate of evaporation and you increase the strength of the hydrological cycle -- and thus the rate at which precipitation must take place -- somewhere. However, with the Hadley cells expanding the dry subtropics are expanding. The climate we associate with Mexico is moving North.

Land has a lower thermal inertia than ocean. Therefore land will warm more quickly than ocean. A higher temperature implies that the relative humidity of the moist ocean air will dry out as it moves into the continental interiors -- which will therefore dry out.

We have seen floods of the century becoming more common. We have seen increases in the length and severity of droughts. We have seen increases in the length and severity of heat waves. And we have seen how increasing the temperature causes ice to melt. All roughly what you would expect in a warming world.

According to statements from Al Gore and David Suzuki in the past, it is already too late to act.

As for "floods of the century", where are you referring to? Some weather records are being broken all the time and there is little evidence floods or droughts are worse worldwide then they were.

Yes, temperature is increasing. It has been increasing since the end of the Little Ice Age. How much of the current increase is related simply to that?

There are many more questions the public has, but because they are never answered, the public has stopped radical action on AGW until our questions are answered.

Paul S claims:

"Yes, temperature is increasing. It has been increasing since the end of the Little Ice Age. How much of the current increase is related simply to that?"

The simple answer is that the present rise in global temperature has got nothing to do with the LIA. Do you honestly think that temperature follows some "pattern" where if it was "cool" before then it has to be "warm" now? That is simply a complete misunderstanding of climate science.

Temperatures change because something, called a "forcing" by scientists, changes. The various forcings for the past thousand or so years are well known, in fact you can go back a lot further and find that temperature changes because of changes in the forcings.

I know that AGW deniers (do you deny that you are one) get this completely wrong and state that scientists do not study all forcings and only study the effects of increasing CO2 concentrations. Well, that shows how little of climate science you actually understand.

Most questions regarding climate science are answered but only if you look in the right places. Denier web sites will not correctly answer questions about climate science. Read the IPCC reports and the scientific literature for honest and accurate information.

Yes Ian, we are well aware of your strident viewpoints on the issue.

Yet, temperatures have often risen from forcings other then CO2. And the world's climate often varies as it is not normally in stasis as you imply.

Drop the 'tude as the public has shown it will not be intimidated by vocal and dimissive AGW advocates.

Paul S whined:

"Drop the 'tude as the public has shown it will not be intimidated by vocal and dimissive (sic) AGW advocates."

What on earth is that supposed to mean?

You have shown over and over again your hatred for science and scientists. You continually show an overwhelming lack of knowledge in the climate science field yet you have so much to say. Too bad that what you say is always wrong and insulting. Please learn some science before showing your ignorance of the points raised.

The public is a lot more informed about climate science than you give them credit for. It is our politicians who should be condemned for their attitude towards climate science. You always seem to think that politicians are the most intelligent and most informed people on earth. You are completely wrong.

Your comment:

"Yet, temperatures have often risen from forcings other then CO2. And the world's climate often varies as it is not normally in stasis as you imply"

is a prime example of your complete lack of understanding or is it an example of your other tactic of putting words in people's mouths? How on earth can you claim that I have said that climate is in stasis? Why not start being honest and try to understand climate science?

Oh Ian, so nice to see you are still the same obnoxious know-it-all you always were. Careful though, or you will get yourself banned from this site again.

Paul S you are wrong again. I was never banned from this site. I got fed up with the way the moderators allowed you and your ilk to slander and smear honest scientists. You know nothing about science yet you come to this site and pretend that you know that all climate science is wrong and that climate scientists are dishonest fraudsters. No wonder I get up set with your lies and dishonesty. I will not sit back and allow the smears that you and your friends (they are definitely not "friends of science"} spread about climate science. You hate science because it will disrupt your selfish lifestyle. What sort of a person does that make you? You are just a dishonest scumball and I will continue to stand up to you and your lies.

I see you are still playing your usual games by refusing to answer simple questions. Are you afraid that honest answers will show what type of a person you really are? Pathetic.

I was sure you had been banned from this site Ian. Pity then.

I see your mind-reading abilities are still intact though, able to discern my selfish lifestyle simply by reading my posts. ESP, now that is definitely science!

Who is this guy Paul S ???? Gosh, some IQ !!! I am thrilled.

paul s, you had written, "The skepticism comes from the apocalyptic scenarios continually laid out by AGW proponents, none of which have come true to date (though they should have)."

I asked, "What apocalyptic scenarios are you talking about that should have come true to date? Do you have a reference for that?"

Now you state, "According to statements from Al Gore and David Suzuki in the past, it is already too late to act."

If someone had said it was too late, that nothing we could possibly do at this point will make any difference it wouldn't mean that we should have already seen an "apocalyptic scenario." It could simply mean that there is inertia built into the system.

For example, that there is an imbalance in the radiation entering the system and the energy leaving the system due to the increased opacity of the atmosphere to thermal radiation. This much is true, and the only way that this imbalance will be eliminated will be for the Earth to heat up sufficiently that the rate at which thermal radiation is emitted will compensate for the increased opacity of the atmosphere to thermal radiation. Alternatively, it could mean that being near peak oil there will be inertia in the system due to investments made in the infrastructure for coal-based energy, tar sands, shale, or what have you.

But such inertia would hardly could as an apocalytic scenario that should have already unfolded. Furthermore it is never the case that it is too late to act. It is just that the longer we take to act the worse the eventual consequences. But they could always be worse. Perhaps by the end of the century half a billion people will face severe food and fresh water shortages because of past emissions. That is better than there being one billion or two billion -- if we were to continue with business as usual for the next fifty years.

Now I suppose it is possible that one or the other of these two guys said something without thinking. Something that would otherwise be entirely out of character for them. Assuming they had -- where is the quote and what is your source? That is normally what people give when they are asked for a reference.

paul s wrote, "Yes, temperature is increasing. It has been increasing since the end of the Little Ice Age. How much of the current increase is related simply to that?"

Likely no more than what we saw by the turn of the century -- in 1900. After all, it is generally considered to have ended by 1850. In fact, the five-year average global temperatures dipped from 1870, rose again around 1880 then dipped then rose again to about the same level by about 1900, varying by approximately 0.2°C. But by about 1925 we were already passing that, more or less never to return.

You can get a good idea of this from the graph here:


It combines 10 different temperature records -- and you will notice that it shows the rate of temperature increase having accelerated over time rather than having decreased. Furthermore, by the mid-1900s we were, to the best of our knowledge, passing the warmest temperatures of the Medieval Warm Period that preceded the Little Ice Age by several centuries. According to satellite records, but for the ups and downs of the solar cycle, the solar output has been steady from about 1960 to slightly decreasing in the late 1990s. But the modern period of global warming took off at about 1975 and hasn't really let up since.

For the Medieval Warm Period you might try the following graph which shows six different reconstructions, three of which reach back to 900 AD. The peak of the Medieval Warm Period appears to have been about 1000 AD.

Surface Temperature Reconstructions for the Last 2,000 Years (2006)
Board on Atmospheric Sciences and Climate (BASC)

We are breaking temperature records. Going back at least 1000 years and more likely 8000 years or more - going back to the Holocene Climate Optimum that marked essentially the end of the recovery from the last great ice age and the beginning of the gradual descent into what would be the next tens of thousands of years from now. But best estimate we have likely already passed that optimum as well -- and would have to reach back even futher to find a warmer period.

Regarding the Holocene Climate Optimum there is a good graph for this by Robert Rhodes here:


It provides a variety of reconstructions and gives the appropriate sources.

paul s wrote, "As for 'floods of the century', where are you referring to? Some weather records are being broken all the time and there is little evidence floods or droughts are worse worldwide then they were."

Well, at least as far as temperature goes, while there are new record daily lows in the US, they are outnumbered by new record daily highs -- and have been since the 1980s. Furthermore they were outnumbered more than 2 to 1 in the 2000s. This is based off of about 1800 weather stations.

Please see:

Record high temperatures far outpace record lows across U.S.
November 12, 2009

As for record heat waves, there is the heat wave of 2003 in Western Europe that was presumably responsible for more than 46,000 deaths.

Please see:

Robine, Jean-Marie; Siu Lan K. Cheung, Sophie Le Roy, Herman Van Oyen, Clare Griffiths, Jean-Pierre Michel, François Richard Herrmann (2008) Death toll exceeded 46,000 in Europe during the summer of 2003, Comptes Rendus Biologies 331 (2): 171–178.

You had the heat wave in Russia that was even more severe and over a wider area in 2010.

You can find more about that heat wave here:

How hot is it? Masters reports nine countries have smashed all-time temperature records, "making 2010 the year with the most national extreme heat records."

I appreciate the information Timothy. I realize a tremendous amount of work has gone into climate scienc and a tremendous of work is ongoing.

I will disagree regarding the heat wave in Europe. Heat waves do occur, and most of the deaths in Europe in 2003 were due to people neglected in their apartments.

Wow. Wait until the cut in heating oil hits the Northeast and Midwest next winter - then you'll really see people dying of "neglect in their apartments." To be sure, the temperature will have nothing to do with it...

paul s wrote, "I appreciate the information Timothy. I realize a tremendous amount of work has gone into climate scienc and a tremendous of work is ongoing."

Judging from what I have read this much is true.

paul s continues, "I will disagree regarding the heat wave in Europe. Heat waves do occur, and most of the deaths in Europe in 2003 were due to people neglected in their apartments."

Being neglected was certainly a factor. But simply saying that they were being neglected doesn't explain much. Why now? Why not before? Either the degree of neglect suddenly became much worse than before -- or something else changed that suddenly turned such "neglect" deadly on an unprecedented scale.

Rather than arm-chair theorizing, some climatologists did actual number-crunching analysis of the summertime temperatures of Europe -- from 1500 to 2000, then again from 2001-2010.

Regarding their methodology, they state:

"To highlight the contribution of summers in the 2001-2010 decade, the analysis was initially restricted to the 1500-2000 period (Fig. 3A) and then updated to 2010 (Fig. 3B). Until the end of the 20th century (20C), maximum seasonal temperatures across Europe mostly ranged 2-3 SDs of their 1970-1999 climatology, with record-holder summers clustering in a few decades of the last five centuries."

The results?

"During the 2001-2010 decade, 500-yr long records were broken over ~65% of Europe, including eastern Europe (2010), southwestern-central Europe (2003), the Balkans (2007) and Turkey (2001). These summers have considerably contributed to the upper tail of the European distribution of summer maxima (Fig. 3, inset plot). Thus, the percentage of European regions with seasonal maxima above 3 SDs (>99th percentile of the 1970-1999 distribution) has doubled within one decade. The 2003 and 2010 summers were the warmest on record over ~25% of Europe, standing as the major contributors to the current European map of the hottest summers."

David Barriopedro et al. (8 April 2011) The Hot Summer of 2010: Redrawing the Temperature Record Map of Europe, Science, vol. 332 no. 6026 pp. 220-224

For a preview of the essay along with highly informative graphs, please see:

Science: After Record-Setting Summer, More ‘Mega-Heatwaves’ on the European Horizon

I've long wondered whatever would/will happen if our large urban and suburban populations were suddenly deprived of our modern heating and air conditioning. We simply are not used to coping with 100+ degree temperatures in the summer and freezing ones in the winter. When I was a girl, many families still had "summer kitchens" and "sleeping porches" on the East coast for dealing with that - and a fireplace or wood or coal stove for supplemental heating in the winter. Not so, any more. Absent electricity and fuel for furnaces, many people would be of necessity "neglected" unless they had someplace to go and a way to get there.

But you were talking about floods and droughts...

You had the record drought in the Southeastern United States in 2007:

"For the first time in more than 100 years, much of the Southeast has reached the most severe category of drought, climatologists said Monday, creating an emergency so serious that some cities are just months away from running out of water."

Drought-Stricken South Facing Tough Choices, Brenda Goodman (NYT) October 16, 2007

Georgia was especially bad hit. But by 2009 we were seeing record flooding.

Please see:

Hell and High Water hits Georgia
September 23, 2009

Same pattern in Australia.

The longest, most severe drought on record for Australia:

"The Murray-Darling basin in south-eastern Australia yields 40 per cent of the country's agricultural produce. But the two rivers that feed the region are so pitifully low that there will soon be only enough water for drinking supplies. Australia is in the grip of its worst drought on record, the victim of changing weather patterns attributed to global warming and a government that is only just starting to wake up to the severity of the position."

Australia's epic drought: The situation is grim
By Kathy Marks, Friday, 20 April 2007

... was followed within a few years by flooding described by one official as being of biblical proportions -- which covered an area equal to France and Germany combined.

For more on this please see:

"Rising waters have knocked out roads and several highways in northeastern Australia, trapping motorists, marooning entire towns and driving thousands from their homes as flooding stretched into its second week on Saturday. More than 200,000 people have been affected so far by the floods, local news media reported."

Australia Floods Show No Signs of Retreating by J. David Goodman (NYT) Dec 31 2010

That was in late December 2010. By mid-February things had taken another turn for the worst:

It didn't take a cyclone for Darwin to break rain records, more than 320 millimetres has fallen since 9am yesterday, the highest 24-hour total on record. This rain is on top of the 131mm which fell in the previous 24 hours. The two-day total of more than 450mm is also a new record. Nearby, Marrara has had 600mm. The persistent, torrential downpours are due to the slow-moving nature of a monsoon low which is hovering about 40km west of Darwin. [paragraph breaks omitted for the sake of brevity]

Record rain floods Darwin as cyclone looms
Brett Dutschke, Wednesday February 16, 2011 - 06:21 EDT

Then there is the recent flooding in Tennessee:

"More than 13 inches of rain fell over two days, more than doubling the previous record of 6.68 inches and leaving as many as 18 dead in Tennessee, including nine in Nashville."

Flooding in Tennessee, May 5, 2010

Stunning NOAA map of Tennessee’s 1000-year deluge
15 sites had rainfall exceeding maximum associated with Hurricane Katrina landfall
May 26, 2010
In Iowa we had the flood of the century in 1993 followed by another flood of the century fifteen years later in 2008.

In 2010-11 we had record flooding in Brazil, Pakistan (with over a fifth of the country covered in water), Australia. We had the second of two 100-year droughts in the Amazon separated by only 5 years...

"'The bigger-picture view, however, is that the Amazon has experienced two '100-year' droughts in the past five years, and there is good evidence that the forests are not adapted to drought ... and the bigger trees die first,' he said. 'There is little doubt that continued droughts of this magnitude and frequency will change the structure of these forests and their ability to sequester carbon from the atmosphere.'"

Another Amazon Drought Spurs Greenhouse Gas Emissions
A severe drought last year in the Amazon rainforest outpaced a 2005 dry spell thought to be a once-in-a-century event, a new study finds
By Lauren Morello and ClimateWire | February 4, 2011

... followed by torrential rains:

Masters on Brazilian floods: Brazil’s deadliest natural disaster in history
The role of near-record sea surface temperatures
January 16, 2011

In my view the droughts are worse than the flooding -- and drought is now causing plant productivity to decline globally.

Please see:

"Earth has done an ecological about-face: Global plant productivity that once flourished under warming temperatures and a lengthened growing season is now on the decline, struck by the stress of drought."

Drought Drives Decade-Long Decline in Plant Growth, Aug 19, 2010

These aren't simply records that are being broken all the time. And the effects are global and decadal.

But extreme weather events are always occurring in some part of the world Timothy. The world is a big place but a drought in Australia doesn't prove an increase in extreme weather.

paul s wrote, "But extreme weather events are always occurring in some part of the world Timothy. The world is a big place but a drought in Australia doesn't prove an increase in extreme weather."

"Prove" isn't a word that gets used in matters of empirical science much unless you are cigarette manufacturer, producer of dioxin, or put lead additives in paint. Empirical science generally deals in evidence which although rarely if ever conclusive is cumulative. Such is the significance of the statement I quoted in my first comment of this thread:

"The justification for a conclusion supported by several independent lines of investigation is generally far greater than that which it receives from any given line of investigation considered in isolation."

That is why I didn't focus exclusively or even predominantly on Australia.

As I pointed out earlier, best estimates we passed the warmest point of the Medieval Warm Period mid-20th Century. You would have to go back well before the Holocene Climatic Optimum 8000 years ago to find a time when the Earth was warmer than it is now. And since the Holocene Climatic Optimum, the long term *natural* trend has been one of cooling which left to its own gradually slip into another ice age tens of thousands of years from now.

But with our carbon emissions we have not only reversed that trend, but will likely continue to warm the planet until well past the point at which there is no Arctic sea ice within the next few decades. People are even arguing over who will have rights to the oil that lays beneath. But we have had sea ice in the Arctic for more than 10 million years.

Please see:

Leonid Polyak et al. (2010) History of Sea Ice in the Arctic, Quaternary Science Reviews, 29, 1757–1778

In a warming world we expect the rate of evaporation to increase. We likewise expect the rate of precipitation to increase. But precipitation and evaporation generally won't occur in the same place. Typically there is considerable distance between where water evaporates and where it ultimately precipitates. And those regions that are already dry will tend to get drier whereas those regions that are wet will tend to get wetter.

But there are exceptions. For example, we expect greater moist air convection from the tropics with increased temperature. This is one of the factors that will cause the Hadley cells to expand.

Now with Hadley cells warm moist air rises from near the equator. As it rises it cools. The relative humidity rises with falling temperature causing the air to give up its moisture through precipitation. Then cooler drier air subsides, resulting in the dry subtropics.

The expansion of the Hadley cells pushes the dry subtropics poleward. This has been observed.

For links to a dozen papers on this, please see:

Papers on Hadley Cell expansion
Posted by Ari Jokimäki on July 27, 2010

As the subtropics are pushed poleward those areas that were just outside of where they were dry out. Like the southern United States.

From the abstract to one of those papers:

"Observations show that the Hadley cell has widened by about 2°–5° since 1979. This widening and the concomitant poleward displacement of the subtropical dry zones may be accompanied by large-scale drying near 30°N and 30°S. Such drying poses a risk to inhabitants of these regions who are accustomed to established rainfall patterns. Simple and comprehensive general circulation models (GCMs) indicate that the Hadley cell may widen in response to global warming, warming of the west Pacific, or polar stratospheric cooling. The combination of these factors may be responsible for the recent observations. But there is no study so far that has compared the observed widening to GCM simulations of twentieth-century climate integrated with historical changes in forcings. Here the Hadley cell widening is assessed in current GCMs from historical simulations of the twentieth century as well as future climate projections and preindustrial control runs. The authors find that observed widening cannot be explained by natural variability. This observed widening is also significantly larger than in simulations of the twentieth and twenty-first centuries. These results illustrate the need for further investigation into the discrepancy between the observed and simulated widening of the Hadley cell."

Johanson, Celeste M., Qiang Fu, 2009: Hadley Cell Widening: Model Simulations versus Observations. Journal of Climate, 22, 2713-2725.

Likewise, there will be the drying out of the continental interiors, particularly during summer. As I have said, ocean has greater thermal inertia than land. It takes longer to heat it up or cool it down. And in a warming world this implies land will warm more quickly than ocean. Thus the relative humidity of moist maritime air will drop more quickly than before as it moves inland and with it the chances for precipitation. In contrast, precipitation may increase during the wintertime. But with an earlier melt this will imply flooding. And at higher temperatures earlier in the year the moisture will tend to evaporate more quickly, leaving less moisture for later in the year. Reduced moisture during the summer will imply a reduction in moist air convection at the land's surface. This will imply higher summertime temperatures and in time a net decrease in plant productivity.

As measured by the Palmer Drought Severity Index (PDSI), we have observed the drying out of land on a global scale.

Please see:

"However, the PDSI suggests there has likely been a large drying trend since the mid-1950s over many land areas, with widespread drying over much of Africa, southern Eurasia, Canada and Alaska. In the SH, there was a drying trend from 1974 to 1998, although trends over the entire 1948 to 2002 period are small. Seasonal decreases in land precipitation since the 1950s are the main cause for some of the drying trends, although large surface warming during the last two to three decades has also likely contributed to the drying. Based on the PDSI data, very dry areas (defined as land areas with a PDSI of less than –3.0) have more than doubled in extent since the 1970s, with a large jump in the early 1980s due to an ENSO-induced precipitation decrease over land and subsequent increases primarily due to surface warming."

Climate Change 2007: Working Group I: The Physical Science Basis, 3.3.6 Summary

... and also see:


And as I have pointed out we have already observed a net global decrease in plant productivity.

Please see:

"Earth has done an ecological about-face: Global plant productivity that once flourished under warming temperatures and a lengthened growing season is now on the decline, struck by the stress of drought."

Drought Drives Decade-Long Decline in Plant Growth, Aug 19, 2010

This global shift in plant productivity is an expected result of global warming, but we didn't expect it so early.

PS to get to my home page (with everything I listed as being there regarding the greenhouse effect) click hyperlink in my name.

I am an environmental scientist. I must admit that I am private sector as I found academia slow and frankly weird. I have in my work around the world, seen clear examples variation in data which in my opinion have connection with climate change (water level, temperature, current variations etc).

I dearly want to accept publically that I subscribe to the concept and probably much more of the climate change POV.

However, the whole "are you a believer", and green movement turns me right off saying anything. Then to have some cr@py flier in the post written by a tv celeb or *shudder* a lecture from a 20 year old environmentalist campaigner telling me that I HAVE to BELIEVE, makes me run to the deniers because atlest I don't need any faith to reject a theory.

Just to be clear, I am not a denier, I change my lifestyle to recycle and use less energy etc and will gladly discuss at length with anyone. But as soon as faced with a "believer" I run a mile from agreeing.

Thanks for your post by the way, I agree with the three causes, but wanted to add my viewpoint which I think is overlooked. The reluctant denier/believer

With what is at stake for the planet and for billions of living beings, does it really make sense to be most moved by your response to people's persona? Perhaps naked contemplation of what we are doing to this incredible planet accounts for some of the zealotry you find so offensive? Couldn't you use your knowledge and awareness to help educate people?


Fine, be skeptical of the green movement and the whole "you have to be a believer" attitude. I actually think thats wise even though I nominally identify myself as green.

More than anything, we need good conservatives who will speak up about climate change, and advocate for solid conservative principles in solutions. Otherwise the polarization of the issue as a right-left battle will end up lose-lose for everyone.

Lob onto this, James F*cking Joyce and friends, you dainty fellows, you.



You display a stunning ability to look at a rising slope and deny its presence. Do you really have the "Ph. D." you claim in your eye-watering amateur graphics?

First graphic: The alleged "arbitrary" reference line is the 1901 - 2000 average of global surface temperature. Why you think plotting instead a positive slope trend line is helpful to your anti-AGW argument is an amusing puzzler.

Second graphic: A classic stab at presenting LOCAL temperature records as directly relevant to GLOBAL temperature records. All while squishing the station temperature charts as much as possible to visually minimize the upward trend in every single plot. Do you have any knowledge of the events impacting climate of Central England, or is it just a location that happened to catch your cherry-pickers eye?

You are enthusiastically committing the sins you falsely accuse scientists of. I suggest you re-read the article you are commenting on and examine your own motivation.

I like this page. Glad its here. As I read through the comments, I just want to suggest that we all think about how we phrase our responses. And if we may, through our language and phrasing, come across just like those we are so outraged by. What if we just came up with a different way to talk about the changes? Maybe a new language that moves the conversation away from "climate change"- he said she said, to concrete events that simply raise the possibility of other things.
Its like working on diversity issues, diversity of thought.

gosh, no condescension in this article, is there?

perhaps people don't believe in AGW because leading AGW scientists have been caught cooking their data...and then lying about cooking their data...and then taking as gospel data from trade publications but pretending it's from peer-reviewed scientific journals...and then, after having been caught out on it all, pretending that it doesn't matter anyway because it's just true, dammit, and stop questioning it!

perhaps people think this is all leading to "stealth attacks on personal freedom" because, oh, I dunno, the government is now telling us what kind of lightbulbs we're allowed to use?

just a thought. but, of course, I'm probably just too stupid to get it.

“How can they believe this stuff?” is also a question many of us are asking about people like you, who just need to hear it from a Democrat and that's good enough proof of anything.

Sorry but your rather predictable list of denialist assertions, endlessly disproven, suggest that your self-analysis is correct.

Or perhaps you are just saying whatever it takes to protect 'your freedoms' from the vast and tightly organized world government climate conspiracy.

So you think it all comes down to politics? What do you need to see before you worry about what we are doing to our planet? I have lived long enough to see a lot of very definite changes, things visible to my eyes. The science merely backs up the obvious. I think human beings don't live long enough. Each takes the world as we find it when we are born as "normal," and the change we see before we die is not enough to worry us...

so- forgive me here- always a curious person- these responses have started to take a familiar shape. What would it take each of you above to stay away from the critiques of each other and have a conversation, discussion, without falling back on some ideology. What has to happen here for you and me and others to engage in civil discourse? about climate and also other things, topics? I look forward to your responses.

This tussel that you and some other bloggers are in is what folks like me see as a "entrenchment." I see how my language defines you.

Lets stop this.

Lets move away from that. Say something new. Something original. Something that represents what you really want to tell people. Not repeat, not develop a mantra about. Something we can say, "Hey, this guy believes and I respect his right to believe what he believes with an understanding that all of our beliefs are simply something we keep telling ourselves.

And they can allow new and interesting information in. That may challenge me, push me into unfamiliar territory that is uncomfortable, but I recognize we are all entitled to believe as we do.

As one person, one human to another, one species trying to talk to others in our species, what really matters here?

What you are arguing about is not the real issue. Let's flush this out. Please.

Thomas Jefferson advocated public education so the uneducated (at that time) could educate themselves about important issues and vote. Lets step back and recognize we all think differently, have different goals and have something to offr.

Hmmm. Promises more than it delivers. To me that looks like Professor Hoffman has managed to distill down the arguments, that's not the same as discovering motivation. I'm working on the theory that climate skepticism/denialism is motivated by the fact that lifestyles will have to change if we give up fossil fuels. It strikes me as bizarre that anyone in this so called debate can declare no pecuniary interest in it, yet people in our time (early 21st century) are the beneficiaries of the way our economy is run whilst unborn future generations are not being properly represented in our decision making process.

I agree. The underlying issue is human change and the conflict is simply a manifestation of it. I've thought about what I'm willing to let go of and wonder how these conversations might go if that was the topic instead of the circular avoidance of one's own part of the problem.

To "Dr. of humans and the environment", "Sally Scorpion" and "Anonomous4":

Your comments are rather naive and perhaps even a "Concern Troll" attempt to falsely elevate the denialist arguments to equal standing with scientifically supported positions.

On the scientific side of this debate there is a fundamental interest in increasing our knowledge of the Earth's climate, correcting errors, improving predictions and acting on that knowledge. If sound evidence somehow emerged that the concern over Anthropogenic Global Warming was either baseless or over-stated (I know, I know, it exists but is being repressed by the conspiracy), I'm sure that even political lightning-rod Al Gore would be delighted.

On the denialist side of this debate we have factual misrepresentation, resolute ignorance (or the feigning of it), fabricated controversies intended to distract the public, and a fixation on personalities and politics. The unending succession of defeated arguments are merely replaced by new variations and started anew. See the earlier comment here by "Titus" for a classic collection.

The tone of the public debate is entirely driven by denialist intransigence. Too bad, because if they put as much effort into shaping how we deal with Climate Change as they do into denying it they might help find a solution that is politically palatable to them.

Interesting point. I don't agree with your assessment.

Is what you are doing working?

Yes, it's working quite well. Self-important denialist blowhards find the spotlight quite uncomfortable.

How is dropping opaque criticisms into a debate working for you? Bet it gives you a little tingle.

No, not at all. And there are no opaque criticisms, although I see you interpret my questions as such.

So I, a person who believes climate change is a reality, find your credibility as an "expert" undermined with me. Not the material mind you- your presentation of it.

I defer back to the opinions of the importance of human emotion above.