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Mann: A Changing Climate Doesn’t Have a Political Agenda

This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO2 has increased since the Industrial Revolution. (Source: NOAA)

The body of evidence for climate change is strong and convincing, and multiple lines of evidence show the changes are caused largely by human activities. The consensus among scientists about the reality of the phenomenon is also convincing.

But from the nature of public discussions on the subject today – at least in the US – that consensus might not be apparent. And somehow the discussion has become a “debate,” which is often divided down political party lines.

“We have to make it clear that the ice sheets are not Republicans or Democrats – they don’t have a political agenda as they disappear,” said Michael Mann, a physicist at Pennsylvania State University, who has been at the recent forefront of climate research. “Certain facts cannot be denied. We have to find a way to steer the conversation to a good faith debate about what we can do about the problem, not this bad faith debate about the reality of it.”

Mann spoke to over 600 writers and journalists on November 7, 2010 at the combined meetings of the National Association of Science Writers and the Council for the Advancement of Science Writing, held at Yale University this week.

Why has the public discourse become so polarizing and why is there a fair amount of legislators and the public who now think that climate change is an elaborate hoax?

Michael Mann, Professor Director, Earth System Science Center, Pennsylvania State University. Credit: PSU

Mann said there has been a large, well funded campaign to manufacture misinformation about climate change, similar to how tobacco companies muddied the waters in the 1960’s on how smoking causes lung cancer and emphysema. It’s no secret that many climate change deniers have ties to the fossil fuel industry.

Mann referred specifically to an infamous memo sent out by GOP political consultant Frank Luntz in 2002 to President George Bush, “which basically said that if the public comes to understand the reality of this problem they will demand policy action to deal with it,” Mann said, “and so you need to manufacture doubt and controversy and uncertainty and cultivate a set of scientists who can act for advocates essentially for fossil fuel industry. And that is what is happened.”

And the science became politicized. “If you can politicize something in today’s political environment,” Mann continued, “you can immediately get half the population on your side. Unfortunately the forces of anti-science — those who deny the science — have been very effective in politicizing the framing.”

Line plot of global mean land-ocean temperature index, 1880 to present, with the base period 1951-1980. The dotted black line is the annual mean and the solid red line is the five-year mean. The green bars show uncertainty estimates. Credit: NASA

But thousands of scientists from almost 200 countries around the world agreed on the most recent Intergovernmental Panel on Climate Change (IPCC) report which said most of the observed increases in global average temperatures is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. Additionally, the US National Academy of Sciences, the National Academies of all the G-8 nations, the American Association for the Advancement of Science and several other scientific bodies have all issued equivalent statements of consensus of the reality of human-caused climate change.

“Certain facts cannot be denied because you don’t like the implications,” Mann said.

Mann is probably best known for known for his “hockey stick” reconstruction of past climate, (Nature, 1998) which shows the world is warmer now than it has been for at least 1000 years. The “hockey stick” has been attacked by climate change deniers, and while new research has better defined the data, it has not been disproven, nor is it the only line of evidence for global warming.

“The hockey stick is not ‘the’ pillar of evidence for the reality of climate change,” Mann said. “There are multiple pillars that include just the basic understanding of chemistry and physics. But it is one of the more visually compelling pieces of evidence for warming.”

The 'hockey stick' chart from the Intergovernmental Panel on Climate Change Third Assessment Report in 2001.

Mann conceded that various other studies and reconstructions of past climate data don’t agree entirely and that there are uncertainties of how much warming will continue because the predictions are based on models, which attempt to predict the future.

“There are legitimate uncertainties, but unfortunately the public discourse is so far removed from where the scientific discourse and controversies actually are, “Mann said. “There is not an uncertainty of the reality of climate change, that sea levels are going to rise, that arctic sea ice will be gone in a few decades or a whole lot of other areas, but we do have an uncertainty in our ability to project regional climate change.”

Mann said scientists don’t completely understand the El Nino and La Nina affects, how cloud feedback will influence the warming and other modeling issues.

However, Mann said, the science has improved over the past few years, and still, there is enough evidence for not just a hockey stick, but an entire hockey league.

“Every reconstruction reveals that the warming is indeed anomalous in a very long term context. Global temperatures are running the highest they have ever run. The twelve month running averages are warmer than they have ever been in documented history. There is no cooling of the globe and no decline to hide,” Mann said referring to the “Climategate” emails that were stolen from East Anglia climate research center and leaked just a few weeks before the Copenhagen climate summit in late 2009.

“Hackers stole thousands of emails –private correspondences between scientists,” said Mann, “and their words were cherry picked, taken out of context and distorted to make it sound like scientists were engaged in some sort of hoax.”

‘Hide the decline’ actually meant the scientists were going to remove unreliable tree-ring data, not cover up any decline in temperatures.

Mann said the real crime was the illegal theft of private correspondence, in addition to the moral crime of intentionally distorting what scientists believe and think.

Mann took his audience to task by saying, “I’d like to say the mainstream media recognized the manufactured controversy for what is was, but they didn’t, entirely.” He also admitted that scientists have not done all they could in the past to make the science clear and their words convincing.

But looking at the current political climate, Mann asked for journalists’ help in the future.

“No doubt we are in for a period of months or even years where climate science is likely to be subject to the sort of politically motivated inquisition that we haven’t seen, frankly, since the 1950’s,” he said. “It is necessary and important for the scientific community to do the best it I can to defend itself from this oncoming attack, and frankly, we are entirely reliant on the willingness of the mainstream media to serve in its role as the critical and independent arbiter and not just report the two sides of the so-called debate, but to actually establish what is fact and what is fiction. The scientists will not be successful against the attack that is coming unless the media is serving its role.”

Mann ended his talk with a picture of his daughter enthralled by a polar bear at a zoo. “I don’t want to have to tell my daughter that polar bears became extinct because we failed to counter a well funded effort to distract the public,” he said.


Note: For any reader who thinks they need to leave a comment to debate the climate change science, before posting, please take a look at the following information:

Mann’s (and other scientists’) data are entirely open and available for anyone to view.

RealClimate.org –– Mann and other climate scientists answer questions and discuss climate change data

NASA’s Global Climate Change Website. Lots of graphs, images and information.



Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.

Comments on this entry are closed.

  • Dark Gnat November 11, 2010, 8:01 PM

    ****Comes back after a quick Google search*****

    Son of a *****! Whay are all the good Ideas taken?

    Oh well, I guess I’ll have to resort to my dehydrated water pyramid scheme…

  • Jan Crab November 12, 2010, 7:07 AM

    Mr. caerbannog666,
    First of all why are you getting so defensive over number 6?
    You make it sound like CO2 is some kind of super polarizing filter that lets in heat (infrared 700-1400 nm) but won’t let is pass back out. No insult intended this is just my limited experience working with light waves….. I have to apologize I had a very long page written because you slammed me but rather than retalliating which is a huge waste of time….. All I want is before a goverment or any special interest group gets a hugh portion of my tax dollars I want to know where my dollars are going and what I’m going to get in return and that they are beiing spent effectively.
    So before we as a world go off reducing automotive contributions of CO2 I’d like to see a written agenda of:
    1- How it is CO2 going to be reduced.
    2- How is progress going to be measured.
    3- At what point are CO2 levels acceptable.

    the larger scientific community needs to prove that
    #1) Identify all CO2 contributers and their respective percentage of contribution. #2) Prove scientifically that Anthroprogenic CO2 is the largest contributer.
    #3) Prove that by reducing automotive emissions alone will improve or reduce climate change. (BTW Good luck with this one.)
    #4) Climate change is caused entirely by CO2.
    Then hold this up to a real scientific debate. (Don’t make a handpicked panel to ensure your outcome)
    Please we cannot move forward as a nation unless we can all get together and work together. All I’m asking for is just a few seemingly simple items of scientific information. Trust me if you can convince me that anthroprogenic CO2 is the main contributer I’ll jump on board but since I have been asking for the this tiny tidbit of information on many different websites and I have yet to recieve a credible answer. So I have done my homework, I have looked through history books and I have read that the best times in history correlates to the warmer times on the planet and conversely the worst times in history are during colder climates. I’m sorry but those are factual historical events. You need to tie more that a snipit of CO2 information into a poltically charged environment to get me to believe in this.
    I do believe the climate is changing. I don’t belive mankind is the main contribuuter to the change. I also do not believe that climate change is all bad. I rather have more of my income to purchase the things I will need to survive that upcoming climate change than to give the federal government more tax dollars to feed the fat cats in washington caviar and steak while the rest of us wither and die hopelessly on welfare and foodstamps.
    And on another note I know am asking the right questions because you are getting upset that means I’m on the right track.
    And finally you have forgotten one of the largest CO2 contributers which frankly frightens me…. What about home heating?
    So when I, a lowly subserviant worker with a family and two children gets upset because you want to feel good about your life by making a change …Please sit back and think of the ramifications of your change. Not just to the environment but the reduced income of the families that will be impacted by increased taxes specifically VAT and CAP and Trade. Both of which reduce my income significantly and provide me very little in return.

  • WeatherRusty November 12, 2010, 8:00 AM

    Thank you for posting this article. Unlike some others here I appreciate that Earth is a planet and that understanding the physics and parameters which underly the warming of Earth increases our understanding of how all planetary bodies respond to changes in radiative forcing. This is astronomy.

  • WeatherRusty November 12, 2010, 8:33 AM


    #1) Anthropogenic CO2 is identified by the isotopic ratio between C12/C13. The growing CO2 concentration carries an increasing C12 abundance proving it’s origin in sequestered, fossilized carbon. Prior to the industrial revolution CO2 likely never exceeded ~280ppm over the past several 100,000 years. It now stands at 390ppm due to fossil fuel burning and deforestation.

    #3) We need to significantly reduce fossil fuel burning from all sources, not just from automobiles. Even if we halted all burning of fossil fuels today, the climate would continue to warm several tenths of a degree Celsius because of the lag in warming the oceans given the current radiative forcing.

    #4) Climate change is not solely caused by CO2. Chances in the Earth’s orbit, intrinsic output by the Sun, coupled oceanic/atmospheric oscillations, geography, the thermohaline circulation and more have caused past climates to change. However, the only factors changing significantly over the past century in such a way that heat energy is added to the system are intrinsic solar and greenhouse gas concentration along with deforestation. The 20th century contribution to warming by each goes something like this…solar 10%….deforestation 20%….long lived greenhouse gases 70%

  • WeatherRusty November 12, 2010, 9:09 AM


    6) Prove that CO2 acts like a one way filter. Heat goes in but it can’t escape.

    All greenhouse gases impede the escape of infrared radiation to space. They slow down the eventual loss to space, thereby increasing the energy contained within the lower atmosphere (troposphere). The heat is not trapped, but rather slowed in it’s escape as the atmosphere is opaque to IR in the lower levels due the the presence of greenhouse gases such as CO2, water vapor, ozone and methane.
    As a result, the surface of Earth is about 33C degrees (59F) warmer than it would otherwise be. Greenhouse gases do not interact with the visible wavelengths from the Sun which are most responsible for warming the surface during daylight hours. Greenhouse gases impede the progress of IR day and night.

  • Lawrence B. Crowell November 12, 2010, 9:10 AM


    Science is not about proof. Proof is the domain of mathematics. Science is about evidence, measurements and data which support theories. Those theories may have some element of internal consistency or mathematical proof, but these theories are never proven to operate in the world.

    The data most adequately supports the theory that our rapid production of CO_2, the increased CO_2 in the atmosphere is correlated with and the cause of increased temperatures in the climate. Nobody will be able to prove this to you if you are adamant in rejecting it. Unfortunately this is a trend in American society, where many millions of people reject an array of science, where now not only is cosmology under the cross hairs, but Einstein’s physics is as well. American’s are electing to become a mulish and ignorant society of people. Ultimately the outcome will be this nation is relegated to irrelevance in the world. For me these trends are a source of deep disappointment in my nation and its people.


  • Dark Gnat November 12, 2010, 11:46 AM

    Watch “The Road Warrior”. Before long, this film will be a documentary.


  • Uncle Fred November 12, 2010, 1:17 PM

    LC, there is little point trying to be rational here. When it comes to my (very close) American friends, I’ve decided it’s best to steer a climate conversation away and onto something else. For Americans this topic has become far too muddied with politics and stoic ideology to be worth arguing over. I avoid this discussion with Americans (particularly Boomers) in the same way I avoid evolutionary discussions, gay/lesbian equality, immigration/multiculturalism and discussions about religion.

    This is deeply troubling as I remember a time when American society was less insular, ideologically bent and more progressive as a whole.

  • Lawrence B. Crowell November 12, 2010, 4:28 PM

    Your summary of American society is pretty spot on. This nation has transformed itself into a Christiological form of Iran. All that we lack is the theocratic regime, but I suspect that is coming before long.


  • ILOVETHESTAR November 12, 2010, 6:50 PM

    *LC-I;ve been a environmentalist for a long time, back to the late 60s’ and try to do my part to keep the US clean. My biggest dream is for the US to constructe the greatest wind powered system in the world, and that would be the Western Great Plains where the winds are more/less as steady/stronger than most seashores.
    The Western great plains are barely inhabited-this area suffers the most violend weather for a temperate area. I am talking about 10’s of thousands of windmills and will many redundancy because an outbreak of tornados will knock out hundreds or a few thousand mills, however, I was always thing about redundant power plants so the system will continue to operate. This windmill system will easily generate many hundreds or not thousands of GIGA-watts of clean power.
    Unfortunately,this will not happen because the US has been playing world ‘police man’ for decades costing trillions of dollars. The entire US infrastructure is old and will require trillions to fix and upgrade-but, the money has been spent on military adventures costing trillions and other crazy spending.
    One of the things that I see that boils my blood is some ‘self proclaim environmentalist’ buying an electric car and use it for show and telll, but, this is a neighbor about a few blocks from me and this so called ‘environmentalist’ have a 1 ton Pickup with dual rear wheels and the biggest load was a weeks worth of groceries, and they have an 8 year old Ford Excursion, dispite the family only having 2 people in the household. Many of these so called ‘environmentalist’ trys to tell the masses ‘do this’ buy smaller vehicles-perhaps a hybrid’ but don’t do what I do. In other words , the US citizens sees/hears this ‘DO THIS, BUT DON”T DO LIKE I DO HAVING GAS GUZZLERS’.
    It will be easy to say quit making large pickups, however, this would affect the local economy and the suppliers and that is a lot of peopel.
    The US is truely wasteful and a petroleum guzzing Country and running out of money to fix its own house due to overseas adventures that took Trillions out of the US economy. But, you can see, there is infighting and serious disruption of local economies trying to change the US to be more energy efficent
    *LC I have to say I disagree about saying I’m into Christiological- I am an athiest.
    The main theme of this post became the most protracted, take no prisoners blogging I;ve seen for this controversial issue.

  • ILOVETHESTAR November 12, 2010, 7:08 PM

    I am sorry I didn’t have my spellcheck on- geeeez I am sloppy in my writing LOL
    I hope you understand what I did say
    Take care all

  • Dark Gnat November 12, 2010, 8:34 PM

    No worries. We’ve been begging for an edit button for a while. :)

    I understand ho you feel about “feel good environmentalists”. There are a lot of folks in my area that have bought hybrids, and give an “I’m helping the environment, but your not” kind of vibe, yet they fail to realize that coal powers most of the nation’s electricity, so even a plug-in hybrid will result in CO2 production, and no one seems to be questioning the batteries, and the toxic chemicals they contain – how will they be disposed?

    There’s also some “do as I say, not as I do” types who drive SUV’s and live in huge houses (or fly around in private jets, like Al Gore).

    There’s only one group of people in America that really are living in a truely environmentally friendly way – the Amish. Everyone makes fun of them, but in the end, they may the only one who make it. Perhaps we can learn a lesson or two from them.

  • ILOVETHESTAR November 12, 2010, 9:47 PM

    *DARK GNAT I told co-workers that Ted Kaczynski (the unibomber)was an environmentalist in its pure form,people thought I was crazy because Ted is as loony to the max but ultra ntelligent, unfortunately he was a killer. When the laughter ended, people thought good and agree he is a pure form invironmentalist but a real nutcase.
    I agree about the Amish being truely environmentally friendly-I never really made fun of them, their lifestyle amazed me and how they kept it quite intact dispite modern conveniences wherever they go.
    Yes, people in general don’t know how toxic used batteries are- what I understand is, they ship boatloads of spent batteries to 3rd world countries so they can tear it apart for valuable parts but these people are getting poisoned and many die a nasty death- batteries are really not the answer. Wind, solar,water power is the way to go-it’s too bad it will take a very long time before the infrastructure is in place to benefit a large part of the US

  • Lawrence B. Crowell November 13, 2010, 4:49 AM

    To be honest what upsets me the most about this is just the mendacity of those who are in the denier camp. The main problem is that it is just yet another example of how some area of science is being stomped down in the social-economic sphere because it raises some issues with our political and economic system. That is the main reason there is this passion. Here at UT a climate change posting can get over 60 responses, sometimes up to 100, because this subject raises these political passions. For me topics on cosmology or black holes are more interesting, and topics I know a whole lot more about, but those do not usually get the tidal wave of responses you get with a climate change topic. This clearly illustrates how this topic strikes heavily at a mostly an emotional or gut level for most people, and the nature of most of these responses betrays that as well.

    The politics of environmentalism gets strange in some ways, just a politics in general does. It has in recent times been equated with Nazism or totalitarianism by the yellowish media journalism, or what passes for journalism. Of course lots of things are being satanized and labeled with political four letter words, such as socialism. Anything the right wing media and political machine does not like is labeled with these terms, appropriately word smithed according to F. Luntz, and you can get your average American knucklehead to react negatively to it.

    The point of environmental concerns is not to save the Earth. Earth will be doing fine a million and 10s or 100s of millions of years from now. The point is ultimately to save our own butts. We risk crashing the life support system we depend upon. We are engineering a mass extinction, maybe one as large as the KT or Permian extinctions, but certainly a moderate extinction period as large as the Miocene extinction. We run the risk that in this process we will be thrown off the Darwinian game table of evolution along with the millions of species we are pushing off now. The extinction rate is about 50 to 100 times the standard rate right now, and 20,000 species are being exterminated each year. If we do that long enough we will be hoisted by our own petard. If this is where we want to go, well fine —- we will really just prove that we are little more than a transient and dysfunctional fluke.

    To be more focused on that, we may have already broken the planetary energy/entropy bank. The global warming process is probably going to run away on us as it is. We may in a few decades begin to do more geo-engineering to reverse these trends. But to prevent global warming from running away we will probably need to do this planetary engineering for several thousand years. We humans almost never engage in anything beyond a century, and most civilizations or empires last not much longer than 500 years. So even if we start geo-engineering in the 21st century it is likely it will be abandoned later on. Either a war will end it, or conservative types will rail on about lowering taxes and ending wasteful spending, or some religious movement will sweep the world or …, well you get the picture. Our goose may already be cooked.


  • Dark Gnat November 13, 2010, 7:02 AM

    It’s amazing how much time, money, resources, and lives have gone into wars that really haven’t made much of a difference in the grand scheme of things. Imagine if we had used those resources to develop a new energy infrastructures. What better way to stick it to OPEC than to say “we don’t need you anymore”.

    The problem is that battery technology isn’t where it needs to be in terms of reliability and safety. Fuel cells would be a much better solution, but the waste product is water vapor, which is actually a more potent greenhouse gas, so it will need to be contained. Also, production of hydrogen will be a challenge – especially of it will b done cleanly.

    As a stop-gap, I think biodiesel and propane would be the way to go. Both burn cleaner, and propane can be stored for long periods of time without going rancid. It’s not perfect, but by relying on domestic sources, we wouldn’t have to import oil from hostile regions, Plus oil tanker use fuel as well. This is something that could have been done rather quickly, had the politicians not been bought out. I’m not talking about just Republicans, btw.

    Right now the best thing we can do is try to limit our gasoline consumption, recycle, and plant trees. Too bad the American people don’t have lobbyist.

    Next time some right-wing politician or AGW denier quotes the Bible, simply respond with “The love of money is the root of all evil.” In other words – Greed.

  • Paul Eaton-Jones November 16, 2010, 2:02 AM

    @ LC.As this goes on I might concur it does not belong here. The main reason is too many of the responses are very embarrassing.

    This is a rather patronising reply which is always directed at anyone who dares question the received orthodoxy. The pro AGW conveniently lump together the deniers with those who are prepared to question the cause [not the evidence]. Anyone who is prepared to ask questions is labelled a planet-killer; a child-killer [you should see some of the rabid comments by the fascist left here in Britain] and be brought before the War Crimes commission at the Hague for Crimes Against Humanity. Reasonable debate will NOT flourish when we have responses like that and the above ones. The pro-AGW people who stand there with their fingers in their ears shouting, “Lalalala, I can’t hear you” are just as foolish and pointless as the ‘oil company’ deniers. They do NOT own the moral high ground and they do not have exclusive rights to wanting the best for humanity. Their self-righteous indignation is getting tiresome.

  • wrangler wayne November 20, 2010, 5:29 PM

    Truthfully, I too am having problems with accepting the Global Warming hypothesis based on GHGs, especially CO2. Evidence does exist from the past (millions of years ago) that CO2 levels were 10 to 15 times more than today’s levels without catastrophic warming. We now know that CO2 levels rose after the past climates warmed and therefore are not the driving cause.

    If man has increased CO2 in the last 100 yrs or so, from 285 to about 385 ppm (100ppm), and is responsible for roughly 4% of all the CO2, bearing in mind that
    only half of it remains in the atmosphere, then shouldn’t it follow, that only 2% of all the accumulated atmospheric CO2 is anthropogenic. So, 2% of 100 ppm means we are responsible for just 2ppm of CO2 in today’s atmosphere.

    I have looked at the mean annual temperatures from NASA and East Anglia (where those from the cities were excluded). I could not find a single case for the last 30 years or so where the plotted line actually angled upwards showing global warming.

    There is a strong inclination for me to conclude that the global greenhouse
    effect (GHE) cannot get noticeably warmer without a major increase in our solar
    sunshine. The GHE as it stands historically, is near or at maximum warmth. The
    GHG molecules are not saturated, but there is not enough energy left in the required wavelengths to cause any additional warming even if we doubled it all.

    Now we are observing a repeat of the Dalton minimum, where the sunspots are greatly diminished. At the same time, the solar gauss is falling and will be below
    1500 by about 2016. Some believe that the sunspots will then wink out and we will flip from a Dalton to a Maunder like minimum. In 5 years we will know more of the truth about all this.

    Looking at the Milankovitch Cycles, we are on the forward falling slope of the previous interglacial warming period. If the earth is still warming, then this theory
    may not be applicable. However, the slope indicates that planet earth is sliding down in temperatures toward another ice age. Again, in 5 years or so, a great piece of the climate puzzle will slip into place.

    I think now is a time for waiting and weighing what all the scientists are trying to tell us. Lets make the rivers and air clean for all. Lets restore the bounty of the oceans and forests. But lets prepare for the changes that are coming, whether it be more warming or cooling, for the benefit of all.