On March 8, the Newport Daily News published a commentary that recycled one of the stalest skeptical arguments around: because water vapor is the most powerful greenhouse gas in the atmosphere, carbon dioxide must be unimportant.

This is incorrect, of course, and has been debunked on several blogs (e.g., here).

In response to this, my colleague Chris Reddy and I wrote this response, published March 16:

Disregard inaccurate view on climate

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In his recent editorial entitled “Climate warnings ignore fact that CO2 has tiny role”, Kevin Doyle provides a series of mistruths and erroneous statements on climate change. His views are not just false but have far reaching consequences that can mislead the public and even policymakers. He argues that the role of CO2 in global change is insignificant. This charge stands in direct opposition to the February 2007 report on climate change by the Intergovernmental Panel on Climate Change, often referred to as the IPCC.

Who should you believe? Let’s compare.

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The IPCC report was written by hundreds of climate experts from 130 countries and was based on peer-reviewed scientific literature. The report has itself undergone several layers of scrutiny; it was evaluated by thousands of other climate experts, critiqued by over a hundred IPCC-member governments, and open to public review.

The IPCC’s previous report, released in 2001 with similar conclusions, was reviewed and endorsed by a blue ribbon panel of the National Academy of Sciences, and its conclusions were subsequently endorsed by the American Meteorological Society, the American Geophysical Union, the American Association for the Advancement of Science, and others. These groups are not composed of a bunch of funding hungry scientists screaming that the sky is falling, but rather distinguished researchers stating that the Earth is warming. Think about this. How often can you get at least 100 professionals, such as doctors or lawyers, to agree on any complex problem?

In the end, the IPCC reports are perhaps the most thoroughly vetted documents in the history of science. These reports are therefore widely regarded as the most authoritative summaries of what we know about global warming and how confidently we know it.

What about Kevin Doyle? He is not a scientist and his editorial underwent no scientific review for accuracy. He could have simply made up everything he said.

Mr. Doyle’s editorial is full of inaccurate claims. We can assure him that the effects of water vapor are indeed recognized by the scientific community and incorporated into climate models. In fact, the warming from CO2 increases the amount of water in the atmosphere via evaporation from the ocean, which in turn leads to still more warming. That’s why most scientists refer to water vapor as a “feedback.”

The general public can believe that there is a massive conspiracy involving thousands of scientists and government officials from virtually all of the countries in the world—or they can believe that one guy with no scientific training in climate science is wrong.

We know who you should believe.

There is a wealth of information on climate change available to the public, including on the relative importance of water vapor versus CO2. We recommend http://realclimate.org or http://gristmill.grist.org/skeptics and urge you to disregard Kevin Doyle’s views.

Andrew Dessler is an associate professor in the Department of Atmospheric Sciences at Texas A&M University and studies the climate effects of water vapor. He received his Ph.D. in chemistry at Harvard University. Christopher Reddy is an associate scientist in the Department of Marine Chemistry and Geochemistry at Woods Hole Oceanographic Institution. He earned his Ph.D. in chemical oceanography at the University of Rhode Island and researches how the oceans respond to human-derived chemicals. Both authors are Fellows in the Aldo Leopold Leadership Program, which trains scientists to effectively communicate science to the public.