I don’t know how many times I have heard or read (including many times in this paper) that 97 percent of scientists agree human activities, particularly through carbon dioxide, is the main reason for dangerous climate change we are supposedly experiencing today. Frankly, I’m getting a little tired of it.

Although these people never quote their sources, there are two main surveys or studies where the authors’ press releases make similar statements. One of those studies was the 2009 Doran/Zimmerman two-question online survey. Neither of the questions concerned whether man’s contribution to global warming was dangerous. A total of 3,146 scientists, all from North America, responded, and the authors’ cite only 77 of these respondents in their 97 percent “consensus.” Another review, which is likely the more currently being cited, is the 2013 Cook review of some 11,944 scientific papers. Of that number, only 4,014 contained an opinion on the issue and only 41 papers endorsed the claim that human activity is causing most of the warming. It should be noted even in Cook’s press release, he stated his findings were in response to humans causing “some” warming, not dangerous warming. Apparently the editors, journalists and other commentators who cite this 97 percent statement, never looked at the underlying questions or data of the surveys or they are ignorantly or intentionally misleading the public.

It might also interest you that in a 2012 survey of climatologists, only 53% agree humans are the main cause of climate change. Once again, even in this survey, the questions did not include the term dangerous climate change.

Finally, I wonder how many of your readers and Americans in general, for that matter, know there has been no global warming for more than 18 years. That’s right: Temperature records taken by satellites and weather balloons show no global warming during those years, and they even might show a slight cooling since about 2002. You should note this has happened when worldwide carbon dioxide production continued unabated. Interestingly a Duke study published April 21 acknowledged “natural variability in surface temperatures” was likely responsible for the “pause” in warming. This then begs the question that if the largest impact of human produced carbon dioxide occurred since 1950, and the only period CO2 and temperatures increased concurrently since then was 1978 to 1997, then why couldn’t this increase have also been due to natural variability? It appears carbon dioxide isn’t really causing dangerous global warming.

Jim Horacek,

Hays