State of the Planet

News from the Columbia Climate School

Answering Claims of the Climate Skeptics: An Introduction

This is the introduction to a series of blog pieces inspired by a report responding to the claims of climate skeptics recently completed by the Columbia Climate Center in collaboration with Deutsche Bank Climate Change Advisors.

Alfred Palmer, "Smoke Stacks." Library of Congress, 1942.

The world’s most prominent scientific academies and international institutions have identified climate change as a concrete reality and a serious threat to humanity. The United Nations Environment Programme considers climate change to be “the major, overriding environmental issue of our time, and the single greatest challenge facing environmental regulators;” the U.K. Royal Society of Sciences has found that there is “strong evidence that the warming of the Earth over the last half-century has been caused largely by human activities;” and the U.S. National Academy of Sciences has found that “a strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks.” In addition to the work of these individual organizations, the Intergovernmental Panel on Climate Change (IPCC) has compiled four comprehensive assessment reports over the past two decades, all of which find with increasing confidence that Earth’s climate is changing and that human activities are responsible.

Yet despite this plethora of evidence that anthropogenic climate change is occurring, there remains a vocal minority of critics, both within the climate community and in the general public, who challenge this accepted position. These self-proclaimed ‘climate skeptics’ question multiple facets of climate change, from the reality of human-induced climate change to the necessity of mitigation efforts. The skeptic perspective can be heard in multiple arenas, including in traditional media outlets. Although there is a consensus regarding the reality and seriousness of human-induced climate change, the media’s practice of ‘balanced coverage’ (in which equal time and attention are devoted to both sides of a story) has given the skeptic perspective a disproportionately strong voice in the debate (see here for more information on this problem of “balance as bias”). In the last decade, the climate debate has flourished in the blogosphere, with the skeptical perspective well represented on blogs such as Climate Audit and Watts Up with That. In response, there a number of blogs which counter these skeptic claims, including Skeptical Science and Real Climate.

After a series of recent events threw into question the accuracy of IPCC reports and the integrity of climate scientists, the intensity of these criticisms and counter-criticisms has increased markedly. This back-and-forth has contributed to a general confusion in the public known as ‘journalistic whiplash,’ whereby contradictory scientific findings are presented in quick succession by a media which craves conflict as a selling-point. This ‘whiplash’ gives the appearance of a heated debate to what is frequently a disagreement over details. As different perspectives are presented in the media or blogs, usually without complete context or explanations of uncertainties, it can be extremely difficult to distinguish factual information from incorrect statements that have been conflated with opinion.

In this upcoming series of blog posts, we will attempt to outline and respond to the most common claims of those skeptical of climate change. In doing so, we hope to pinpoint the major sources of confusion or inaccuracy and to clarify what science can (and can’t) tell us about Earth’s climate. Each post will consist of a single skeptic argument (such as, “Temperatures haven’t risen since 1998” or “Climate models are defective”), followed by a brief response in simple terms and a longer explanation with more scientific detail. These posts will be grouped into three broad categories which correspond to the main threads of skeptic arguments: claims that Earth isn’t warming; claims that Earth may be warming, but man-made emissions of CO2aren’t responsible; and claims that Earth may be warming and CO2 may be responsible, but we don’t need to act to counter this trend.

Skepticism is broadly defined outside the field of climate change as “an attitude of doubt or a disposition to incredulity.” This inclination to question widely held beliefs plays a critical role in the evolution of scientific knowledge, and is necessary for a comprehensive understanding of any scientific subject. Discussions in the current climate debate are hindered by the complexity of climate science as well as by misinformation that have together led to an atmosphere of general confusion. In the spirit of traditional scientific skepticism, we will use this series of blog posts to examine the science behind climate change and to address some of the most common sources of disagreement. We hope that it will provide some clarity in the midst of confusion, and we look forward to your questions and comments.


United Nations Environment Programme:, accessed 11/12/10.

The Royal Society, Climate Change: a Summary of the Science, p. 1. (London, UK: September, 2010).

U.S. National Academy of Sciences:, accessed 11/12/10.

Boykoff and Boykoff. “Balance as bias: global warming and the U.S. prestige press.” Global Environmental Change 14 (2004): 125-136.

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13 years ago

One simple question of fact to start with. Climate Audit was set up in response to Real Climate, not the other way round. One of the factors that seemed to influence the setting up of Real Climate was the publication in Energy and Environment of the first McIntyre and Mckitrick critique of Mann’s work.

H. Tieben
13 years ago

I can’t understand how anybody can have the slightest doubt about what’s happening to the climate. Just take a look at the glaciers.

13 years ago

H. Tieben, you describe what we all think. It’s a constant battle between the economy and the environment.