Stuart Gaffin is a climate researcher at Columbia University and a regular contributor with his blog “Exhausted Earth”. ThomsonReuters is not responsible for the content – the views are the author’s alone.

Often when seeing anti-environmental commentary about global warming in the media, I feel like the first question I would like to ask these commentators is: “Why do you deny that carbon dioxide (CO₂), which is increasing in a major way in the atmosphere, is a greenhouse gas?”

If they were to start their answer: “I don’t deny it …” I would think “Good, we’ve made some progress.”  However, as I think would often be the case, if they start their answer: “Because …” we should be ready to pounce on the ensuing nonsense.

Here’s a key example of such nonsense from a former weatherman:

“Now allow me to talk a little about the science behind the global warming frenzy. I have dug through thousands of pages of research papers, including the voluminous documents published by the United Nations Intergovernmental Panel on Climate Change. I have worked my way through complicated math and complex theories. Here’s the bottom line: the entire global warming scientific case is based on the increase in carbon dioxide in the atmosphere from the use of fossil fuels. They don’t have any other issue. Carbon Dioxide, that’s it.

Here is the deal about CO2, carbon dioxide. I  estimate that this square in front of my face contains 100,000 molecules of atmosphere. Of those 100,000, only 38 are CO2; 38 out of a hundred thousand. That makes it a trace component. Let me ask a key question: how can this tiny trace upset the entire balance of the climate of Earth? It can’t. That’s all there is to it; it can’t”. 

This might be funny if it weren’t for the fact that editorial pages like the Wall Street Journal and conservative news sources such as Fox News  treat such individuals as scientific authorities on climate change.

Leaving aside the fact that it is the molecular structure of CO₂ that is the basis for its greenhouse effect with respect to absorbing heat radiation from the Earth’s surface and warming the climate, or that with no CO₂ in the atmosphere our planet would freeze over, the numbers argument above is just unforgivable. The current and future higher concentrations of CO₂ in the atmosphere are precisely accounted for in climate models that simulate present and future warming.A seemingly small concentration of a gas in the atmosphere is not a measure of its potential environmental or health impact. Indeed, if anything, the more trace level a gas is in the natural atmosphere, the more powerful its environmental impact is likely to be.

For example, I would ask any reader that accepts the above argument, with all its hubris (“…that’s all there is to it …” !!) to consider this: Would you mind if there were just 38 molecules of carbon monoxide (CO) out of 100,000 molecules of atmosphere in ‘front of your face’? If you don’t mind, you should know that, after a few hours of exposure, you would probably be dead.

Similarly weather reporters surely should know that dangerous air pollution levels of gases like ozone (O₃) are measured in very low concentrations of 100 molecules per billion molecules of atmosphere! After all, ozone levels are a routine part of weather forecasts today.