Paul MacRae, June 15, 2008

How is it possible for a theory, which is false in its component parts, to be true as a whole?

— Jean Francois Revel, Neither Marx nor Jesus, p. 15

After reading some of the False Alarm website, which criticizes the scientific “consensus” that humans are the principal cause of global warming, a friend sent me an email the other day that read, in part:

How can many, many respected, competitive, independent science folks be so wrong about this (if your premise is correct)?  I don’t think it could be a conspiracy, or incompetence…  Has there ever been another case when so many “leading” scientific minds got it so wrong?

This is a really good question. I’m not a climate scientist (but, then, neither is Al Gore); I’m an ex-journalist, now an academic. I teach professional writing. How dare I claim to know more than, say, the 2,000 or so scientists who contribute to the reports of the UN’s Intergovernmental Panel on Climate Change (IPCC)? These are the experts, after all, and they say that humans are the principal cause of global warming at the moment. How could the experts possibly be wrong?

Of course, many, many people (not just scientists) have been wrong before on many, many topics. Until the 1960s, few scientists believed in continental drift. Millions of intelligent people continue to believe in communism even after the collapse of the Soviet Union  in 1989. After Rachel Carson’s Silent Spring came out in 1962, many, many people believed DDT was bad when in fact, if used properly, DDT could have saved millions of lives in places like Africa. Science is a process of systematically weeding out the wrong ideas and replacing them with better wrong ideas, as it were.

But getting on to global warming:

Getting it wrong at the IPCC

How can so many be so wrong? Well, for a start, here’s a comment from the Summary of the IPCC’s 2007 report:

Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.

The only problem with this statement is that it isn’t true: it’s now widely accepted in scientific circles that the climate system hasn’t warmed since 1998. Yet, somehow, the writers of the 2007 IPCC report managed to find increases in warming when the planet wasn’t warming, which was a triumph of ideology over fact.

Curiously enough, this lack of warming still hasn’t been officially announced to the public. Why not? You’d think the news would make big, bold, front-page headlines: GLOBAL WARMING OVER (at least for now). Unfortunately, too many scientific careers (and billions in scientific grants) are riding on the hypothesis that humans are the main cause of warming to give the hypothesis up that easily.

How can so many be so wrong? Ten years of no warming is a bit more than the normal year-to-year fluctuations — it’s more like a trend — but none of the IPCC’s sophisticated computer models predicted it. Yet, since carbon emissions are continuing to increase, the trend should be continuous warming if humans are the principal cause of climate change, as the IPCC believes (although it puts its bias in probabilistic language — “it is highly likely that…”).

The IPCC’s bogus ‘hockey stick’

How can so many be so wrong? In its first report, in 1990, the IPCC used a graph by H.H. Lamb, the dean of climatologists, to illustrate climate change over the past thousand years (see Figure 1):

Temperatures over the last 1,000 years: H.H. Lamb
Figure 1. Lamb graph of temperature over the past 1,000 years

Note the pronounced rise about 1000 AD (the Medieval Warm Period) and the fall about 1400 (the Little Ice Age). Note that the Medieval Warm Period is a bit warmer than today.

However, in its 2001 report, the IPCC chose to go with the graph shown in Figure 2.

Because the graph looks like a hockey stick, that’s what it’s been called. Note how the Medieval Warm Period (when the Vikings settled Greenland) is gone. So is the Little Ice Age. Note the apparently unprecedented rise in temperature in the 20th century (the blade). The IPCC liked the hockey stick because it fit the message the IPCC wants to convey: it’s really, really warm — the warmest in a thousand years! — so we should be very worried.

The hockey stick was based on research by Dr. Michael Mann and associates. Mann also happens to be one of the IPCC’s lead authors — so much for objectivity. But, although the IPCC featured the hockey stick prominently in its reports, nobody had bothered to check its accuracy, even though

IPCC hockey stick graph
Figure 2. IPCC hockey stick graph of the past 1,000 years

it wiped out the two most prominent climate features of the last millennium.

Finally, a Canadian mining executive named Steve McIntyre reviewed the numbers and discovered they were bogus: the mathematical model Mann et al. used produced the hockey stick regardless of what data was put in and the graph was based on flimsy sampling methods.1

Of course, McIntyre was vilified for his pains, but the IPCC withdrew the graph for its 2007 report. The IPCC’s claim now is that the current temperature is the warmest in “400 years,” which isn’t that startling since 400 years ago the planet was unusually cold (the Little Ice Age).

The IPCC’s mission: Blame humans for warming

How can so many be so wrong? Here’s the IPCC’s mission statement:

The role of the IPCC is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation 2 (emphasis added).

There’s nothing wrong with having a mission; it’s unavoidable. The IPCC is a kind of global-warming think tank and most think tanks have a mission. The mission of the Fraser Institute, for example, is to promote free markets. The mission of the Canadian Centre for Policy Alternatives is to promote socialism, although its mission statement doesn’t say this directly. Both seek to be as “objective” as possible, but they start from different premises.3

Similarly, the mission of the IPCC is to investigate and promote the idea that human activities are the main cause of global warming. Its mandate isn’t to explore the idea that perhaps humans aren’t at fault.

However, a key difference between the IPCC and the Fraser Institute, or the IPCC and the Centre for Policy Alternatives, is that most readers of a Fraser Institute or CPA document know that the organization has a bias and take that into account in assessing the information they are receiving. The IPCC, on the other hand, promotes itself to the public as a fully scientific, unbiased source of information on climate change, when as anyone who reads its mission statement carefully (few, apparently, have bothered) would know, it has a very strong bias.

‘Review by governments’ isn’t science

How can so many be so wrong? The next sentence of the IPCC’s mission statement reads: “Review by experts and governments is an essential part of the IPCC process” (italics added). Yet, surely if the IPCC was looking at climate change from a balanced, purely scientific perspective, its findings would not be subject to “review by governments,” which are political bodies with political, not scientific, agendas. Does anyone today believe that Galileo should have had to present his findings to the Church before publishing them? True science is not subject to review by governments.

How can so many be so wrong? No truly objective scientific body would be striving for “consensus” in its reports, although we expect consensus from think-tank publications — the Fraser Institute isn’t going to put out a document calling for the nationalization of the Canadian oil industry, for example.

Yet reaching a consensus was the IPCC’s task when it was started in 1988 by the World Meteorological Organization and the United Nations Environment Program. What consensus? The one approved by the politicians who bankrolled the process, which is why, again, and incredibly, the IPCC’s conclusions undergo “review by governments.”4  That is, the IPCC has to meet a political (ideological) as well as a scientific agenda.

This striving for consensus meant that the IPCC was not interested, right from the start, in giving legitimacy to views that didn’t fit its mandate. For example, the 1990 IPCC report said of dissenters: “Whilst every attempt was made by the Lead Authors to incorporate their comments, in some cases these formed a minority opinion which could not be reconciled with the larger consensus5 (italics added). So why not publish the minority reports along with the majority report so the public can see the full range of opinion?

And, since the IPCC’s mission isn’t to investigate possible natural causes of climate change but to determine the role of “human-induced” climate change, it’s not surprising that the IPCC finds what it seeks. How do we know there is bias rather than objective science at work? Because when scientists who aren’t part of the “consensus” suggest other, natural mechanisms for climate change, they do not receive the respectful, if critical, hearing you’d expect from disinterested scientists. Instead, they are denounced as heretics.

Official Climate Science calls critics ‘immoral,’ ‘irresponsible,’ ‘dangerous’

For example, when physicist Henrick Svensmark suggested that cosmic rays might be one explanation for climate change, former IPCC chairman Bert Bolin denounced his theory as “extremely naïve and irresponsible,” and another scientist at a conference called it “dangerous.”6  Similarly, research questioning the validity of ice-core CO2 readings was declared “immoral.”7 These responses are reminiscent more of religion than science.

What is the proper scientific attitude toward new ideas? Here’s what philosopher of science Karl Popper had to say:

If you are interested in the problem which I tried to solve by my tentative assertion, you may help me by criticizing it as severely as you can; and if you can design some experimental test which you think might refute my assertion, I shall gladly, and to the best of my powers, help you to refute it.8

This is the opposite of the IPCC’s approach, which is to shout down or ignore critics, and even make it difficult for them to continue their research or get published. When the Official Science peer-reviewed journals refuse to publish articles by skeptics, as they do, Official Science can then say the skeptical science doesn’t have peer-reviewed publications: it’s a Catch-22.9 Official Climate Science has made up its mind as to the (human) culprit in global warming and isn’t interested in any other suspects.

All of the above may be wrong, of course: the IPCC may be doing a totally accurate, bang-up job of assessing the science on climate change. Unfortunately, the process — “review by governments” and a bias toward human causes of climate change  — means that the IPCC is not the objective scientific body it presents itself as to the public. It is driven by agendas other than science.

I began serious research into climate change in May, 2007, following an attack by Dr. Andrew Weaver, a leading computer-modeling climatologist from the University of Victoria’s, on a column I’d written in the Times Colonist newspaper.

Curiously, while agreeing with me on many of the scientific points I’d made in the column (temperature precedes CO2 increases, for example), Weaver then declared the column to be lacking in “scientific literacy,” presumably because it challenged the “consensus” view that humans are the primary cause of climate change at the moment.

We know this is Weaver’s view because he says so: “Anthropogenic forcing alone is insufficient to explain the warming from 1910 to 1945 but necessary to reproduce the warming since 1976.”10 Somehow, the planet warmed from 1910 to 1945 without our help, but apparently it couldn’t have warmed after 1976 without our help.

I read a lot of science, so the “scientific illiterate” charge didn’t make much sense to me, but perhaps I was lacking in knowledge. So started to seriously investigate the issue of climate change.

Truth in the balance

How can so many be so wrong? I began my research with Al Gore’s Earth in the Balance, and discovered something very interesting: a huge scientific hole in Gore’s argument.

Gore ties global temperature to carbon dioxide levels. The implication is that as CO2 levels increase, temperature increases. In both the book and his movie and book An Inconvenient Truth, Gore has a chart showing the ups and downs of temperature and CO2 for the past 450,000 years — it’s a roller coaster ride (see Figure 3 below), with the clear implication (never quite stated directly) that CO2 drives temperature.

Glacials and interglacials over 450,000 years
Figure 3. Carbon dioxide and temperature over the past 450,000 years

But, if changes in carbon dioxide levels caused changes in temperature, as Gore wants us to believe, then what caused the changes in carbon dioxide levels? Gore doesn’t say in Earth in the Balance beyond a footnote reference to “variations in solar intensity.”11 He says nothing at all about “variations in solar intensity” in An Inconvenient Truth, book or movie.

How can so many be so wrong? Here are the scientific facts as attested to by almost all climate scientists, including Weaver. Changes in CO2 levels follow global temperature changes by several hundred years. CO2 doesn’t drive the climate, at least not in the recent geological past. And the roller-coaster ride of glacials (cold times) and interglacials (warm times) are almost certainly caused by “changes in solar intensity” due to something called the Milankovitch cycles.

The earth’s position in relation to the sun is not constant and over the past two million years, every 100,000 years or so, the earth goes into a glacial phase of about 80,000 years, following by a warm interglacial phase of 10,000-20,000 years. We’re in an interglacial right now — in fact, we’re more than half-way through it.

For a greener planet we need more CO2, not less

Not only that, but while the planet’s temperature has been fluctuating up and down (so much for the “balance of nature”), the planet’s carbon dioxide levels have been steadily falling for the past 170 million years. Carbon dioxide levels are the lowest they’ve been in 250 million years (see Figure 412), and if the levels get too much lower — say 150 parts per million of the atmosphere rather than the current 380 ppm — almost everything on earth will die because CO2 is essential to life.

CO2 and temperature over 600 million years
Figure 4. Temperature and CO2 levels over 600 million years

How can so many be so wrong? A fact that Official Climate Science prefers to ignore is that higher levels of CO2 are good for most forms of plant life. That’s why hothouse growers pump CO2 into their greenhouses–the plants grow better. Growers aim for a CO2 level of about 1,200 ppm, or three times the current concentration of CO2 in the atmosphere. A world with more CO2 will be a greener world, not a devastated world, but for some reason this scientific fact doesn’t figure in the Al Gore or “consensus” climate script.

How can so many be so wrong? Our biggest climate problem on the horizon isn’t warming and higher CO2 levels, it’s lower CO2 levels, global cooling, and a new ice age that will be far, far more catastrophic than a few degrees of warming. For some reason, the public isn’t told much about this, and yet these are scientific facts. The problem is, they aren’t convenient facts for the global-warming “consensus.”

Al Gore’s Inconvenient Truth book and movie are where most people have gotten their information about global warming and yet in both he ignores the Milankovitch cycles. Why? Because the cycles don’t support his argument that CO2 determines temperature. In other words, he’s being scientifically dishonest. A British judge even ruled that nine of Gore’s key contentions in An Inconvenient Truth were scientifically unjustified, and that Gore’s film couldn’t be shown in British schools without a disclaimer that this was political propaganda, not science.

None of this is a problem. It’s a free country and Gore can write what he likes — lots of nut cases write books on climate (I may be one of them). The problem is that even though most of his book and movie are completely wrong, Gore is not criticized by the Official Climate Science community.

James E. Hansen, head of NASA’s Goddard Institute for Space Studies, has even said he supports Gore because “he has the bottom line right.”  Gore’s facts are wrong, but he has the bottom line right? I wonder what Hansen would say if one of his students turned in a paper that had the “bottom line right” but the wrong facts.

How can so many be so wrong? Why didn’t the climate scientists at the Bali conference in December 2007 stand up as a body and correct UN Secretary General Ban Ki-Moon when he declared: “One path leads to a comprehensive climate change agreement, the other to oblivion. The choice is clear.” Surely a body of scientists must be aware that the planet has been much warmer in the past, with much higher levels of carbon dioxide (see Figure 4 above) and didn’t face “oblivion.” Why didn’t they educate Ban (and through him the public) with a few geological facts?

How can so many be so wrong? Not only that, but rather than stand up as a body and warn the public about Gore’s errors, the climate community accepted a Nobel Peace Prize with him. This is as blatant an act of scientific dishonesty as any in the history of science.

Violating the scientific code of ethics

In the news in 2007 was a proposal to create a scientific “code of ethics” that would include, as one of its seven tenets, the following: “Do not knowingly mislead, or allow others to be misled, about scientific matters. Present and review scientific evidence, theory or interpretation honestly and accurately.”

After reading Earth in the Balance, and then learning that Gore’s errors were not only not being challenged by climate scientists but that Gore was largely supported by the climate science community, I knew there was something seriously wrong with the ethics of climate science. Although there is no official scientific code of ethics, surely it is incumbent on any scientist not to “knowingly mislead, or allow others to be mislead, about scientific matters.”

Yet, here are the words of leading climate scientist Stephen Schneider of Stanford University:

On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but — which means that we must include all the doubts, the caveats, the ifs, ands, and buts. On the other hand, we are not just scientists but human beings as well. And like most people we’d like to see the world a better place, which in this context translates into our working to reduce the risk of potentially disastrous climatic change.

To do that we need to get some broad based support, to capture the public’s imagination. That, of course, entails getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have. This “double ethical bind” we frequently find ourselves in cannot be solved by any formula. Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both.13 [emphasis added].

Here’s what James E. Hansen, a leading figure in the global-warming pessimist camp, has to say about the need for scientific honesty:

Emphasis on extreme scenarios may have been appropriate at one time, when the public and decision-makers were relatively unaware of the global warming issue, and energy sources such as “synfuels,” shale oil and tar sands were receiving strong consideration. Now, however, the need is for demonstrably objective climate forcing scenarios consistent with what is realistic under current conditions.14 [emphasis added].

Finally, the Nobel Peace Prize-winning Al Gore:

In the United States of America, unfortunately we still live in a bubble of unreality [about global warming]. And the Category 5 denial is an enormous obstacle to any discussion of solutions. Nobody is interested in solutions if they don’t think there’s a problem. Given that starting point, I believe it is appropriate to have an over-representation of factual presentations on how dangerous it is, as a predicate for opening up the audience to listen to what the solutions are, and how hopeful it is that we are going to solve this crisis. Over time that mix will change. As the country comes to more accept the reality of the crisis, there’s going to be much more receptivity to a full-blown discussion of the solutions.15 [emphasis added].

Why ‘scary scenarios’? Why not just tell the truth?

How can so many be so wrong? Why are “extreme scenarios,” “scary scenarios” and “over-representation of factual presentations” necessary? Why not just give the public the straight facts? Probably because Official Climate Science doesn’t have the facts to back up its case.

The scientists have tons of data, of course, and an hypothesis — that rising temperatures are due to rising human carbon dioxide emissions and that the result is going to be disastrous. But an hypothesis is all they have and, as it turns out, even that hypothesis is wrong — temperatures aren’t rising at the moment.

Even if temperatures were rising, there is no conclusive data linking CO2 and temperature (indeed, in the past, temperature drove CO2, not vice-versa) because the climate system is much too complicated to be driven by one factor, as the climate scientists well know. It makes no more sense to say “humans are the principal cause of global warming” than it does to say “clouds (or cosmic rays or volcanoes or ocean currents) are the principal cause of global warming.”

Yet, although they are aware that correlation does not prove causation, and perhaps sincerely believing the world is in peril, some scientists deliberately or unconsciously attempt to mislead the public into accepting an hypothesis as scientific fact. What do they offer as proof? Not hard scientific evidence but the “consensus” — a large number of scientists who have agreed to accept the hypothesis as scientific fact, therefore it must be a fact.

Many scientists are afraid to speak out

How can so many be so wrong? On the “consensus,” Nigel Lawson, a former Spectator editor and Britain’s Chancellor of the Exchequer from 1983-89, writes:

It is sometimes claimed … that the scientific account published in the reports of the [IPCC] … represents the unanimous view of some 2,500 scientists. In fact, the physical science section of its most recent report (IPCC, Climate Change 2007, February 2007) was written by 51 named authors (and subsequently edited by representatives of member governments and the UN). The other scientists engaged in the process were involved as “reviewers” and the like, and many of these have made clear their disagreement with important aspects of the IPCC account.

Then there is the even larger number of reputable climate (and allied) scientists not involved in the IPCC process, literally hundreds of whom have, at one time or another, made public their disagreement with (often fundamental) aspects of the conventional wisdom. Finally, there are large numbers of dissenting climate scientists who have chosen not to stand up and be counted, for fear that to do so would damage either their career prospects or their chances of securing research grants. All that can be said with confidence is that the dissenting minority of reputable climate (and allied) scientists is a sizeable one.16

I could go on and on, but to detail everything I’ve learned about the sorry scientific and ethical state of climate science would require a book, which is what I am writing and which I hope will appear in 2009. Here, though, are a few more tidbits:

  • Carbon dioxide’s effect on temperature is logarithmic. That is, the more CO2 you put in, the less effect it has on temperature. At this point, a doubling of CO2 will produce less than one degree Celsius of temperature change. Therefore, there is no need to fear a “runaway” greenhouse effect. The public, in general, is not informed about or actively misled on this.
  • It is unusual, in earth’s history, to have ice caps at all. The planet won’t go into “oblivion” if we lose the ice caps, which is highly unlikely in any event, as climate science well knows. We may have to move or protect some cities from rising sea levels in the worst-case scenario, but this is over hundreds or thousands of years.
  • There is no 100 per cent “consensus” on the causes of climate change, as Al Gore claims, or even a huge majority consensus. Most geologists, for example, don’t accept that humans are the main cause of climate change because they know, from their paleo-history, that the earth has been warmer than today and with higher CO2 levels than today with no disaster, and that today’s climate is well within past natural variation. Proof? Take a look at the roller-coaster temperature chart above, which Gore uses in his presentation. Notice that the three previous high-temperature points (the three previous interglacials) are all higher than today’s peak temperature. In other words, interglacials in the past were warmer than today’s interglacial, without any human influence at all. It’s plain as day in Gore’s presentation but, of course, he doesn’t mention the previous interglacials because that would destroy his argument. It’s a case of hiding the truth in plain sight and hoping nobody will notice.
  • We have far better things to spend billions of dollars on, such as reducing world poverty, than trying to “stabilize the climate,” which is an impossible task. Climate science knows this, but insists we should try anyway.

Let me conclude by saying this:

I can’t claim to be an expert on climate science. But, as a former journalist, I do claim an ability to know when someone is not dealing honestly with the public. And everything I have read since I began my research convinces me more and more, as my book title argues, that most of what we, the public, have been told about global warming is misleading, exaggerated, or plain wrong, including the claim that the planet is warming.

You don’t need to be a climate expert make this discovery, as I have. All you need is time, some research, and an idea of where to look. Of one fact I am now certain: the public won’t get a balanced, objective viewpoint from the Official Climate Science “consensus.”

How can so many be wrong? The real question, once we’ve seen the way “consensus” climate scientists spin the facts, is: how can we be sure anything they tell us is right?

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  1. Ross McKitrick, “The Mann et al. northern hemisphere ‘hockey stick’ climate index: A tale of due diligence.” In Patrick Michaels, Shattered Consensus: The True State of Global Warming. Lanham, MD: Rowan & Littlefield, 2005, pp. 20-40.
  2. IPCC, “16 Years of Scientific Assessment in Support of the Climate Convention,” December, 2004, p. ii.
  3. The CCPA’s mission statement reads: “The Canadian Centre for Policy Alternatives is an independent, non-partisan research institute concerned with issues of social and economic justice. Founded in 1980, the CCPA is one of Canada’s leading progressive voices in public policy debates.” In other words, it’s socialist in its approach. The Fraser Institute’s job description is a little more forthright: “Our mission is to measure, study, and communicate the impact of competitive markets and government intervention on the welfare of individuals.”
  4. IPCC, “16 Years of Scientific Assessment in Support of the Climate Convention,” available at See Richard Courtney’s “Global Warming: How it all Began” at, which argues that former British Prime Minister Margaret Thatcher, as a new leader, used concern about global warming to bolster her international reputation. The Global Warming Swindle film suggests Thatcher was looking for a way to increase Britain’s use of nuclear power, against fierce popular opposition, and hoped fears of fossil-fuel emissions would pave the way to acceptance of nuclear plants. Michael Crichton, in his novel State of Fear, p. 500, suggests that with the fall of Soviet Communism, Western governments needed a new “enemy” to keep its citizens “in a state of perpetual fear” and global warming was it.
  5. Climate Change 90. Quoted in Vincent Gray, The Greenhouse Delusion: A Critique of Climate Change 2001, p. 7. See also Gray, “Climate Change 95: An Appraisal.” Available at
  6. Henrik Svensmark and Nigel Calder, The Chilling Stars: A New Theory of Climate Change. Cambridge: Icon Books, 2007, pp. 73-74.
  7. Lawrence Solomon, “The ice-core man.” National Post, May 4, 2007. Available on the National Post website as part of the “Deniers” series.
  8. Karl Popper, Conjectures and Refutations: The Growth of Scientific Knowledge. New York: Routledge & Kegan Paul, 2007 (1963), p. 35.
  9. University of Victoria climatologist Andrew Weaver uses this tactic in his article “The evidence is overwhelming — global warming is happening and we’re the cause of it,” in the University of Victoria’s Ring, Feb. 4, 2000, when he writes: “The IPCC does not ignore dissenting opinions — it ignores unpublished research.”  However, major scientific journals, in common with the IPCC, have made up their minds and make it very difficult for skeptics to publish their research. See Robert Matthews, “Leading scientific journals ‘are censoring debate on global warming’,” The Telegraph, May 1, 2005, available at Matthews’ story begins: “Two of the world’s leading scientific journals have come under fire from researchers for refusing to publish papers which challenge fashionable wisdom over global warming.” Those two leading journals are Science and Nature. In 2001, Nature ran an editorial calling those who don’t believe warming is primarily caused by humans “unscrupulous,” “specious,” and engaged in “bogus” research. Another journal, Scientific American, devoted four articles to a hatchet-job on Bjorn Lomborg’s The Skeptical Environmentalist. See “Misleading math about the earth: Science defends itself against The Skeptical Environmentalist.Scientific American, January, 2002. On his own website, Lomborg demolished his four critics, who clearly hadn’t read The Skeptical Environmentalist with any care. No wonder there are few peer-reviewed articles from the skeptical side of global warming: there’s little incentive for skeptics to send articles to any of these publications.
  10. Francis W. Zwiers and Andrew J. Weaver, “The Causes of 20th Century Warming.” Science 15 December 2000: Vol. 290. no. 5499, pp. 2081-2083.
  11. Al Gore, Earth in the Balance: Ecology and the Human Spirit. Toronto: Penguin Books, 1993, p. 96.
  12. Available at http://www.geocraft. com/WVFossils/greenhouse_data.html.
  13. Schneider is quoted in Jonathan Schell, “Our Fragile Earth.” Discover, October, 1989, pp. 45-48. See also Stephen Schneider, “Don’t Bet All Environmental Changes Will Be Beneficial,” APS (American Physical Society) News, August/September 1996, p. 5. Available at
  14. James E. Hansen, “Can we defuse the global warming time bomb?” Natural Science, Aug. 1, 2003. Available at
  15. David Roberts, “Al Revere: An interview with accidental movie star Al Gore.” Grist, May 9, 2006. Available at
  16. Nigel Lawson, An Appeal to Reason: A Cool Look at Global Warming. New York: Duckworth Overlook, 2008, pp. 107-108.