Contrary to Terry Maley’s June 15 letter to the editor, the 2013 scientific paper he refers to, “Quantifying the Consensus on Anthropogenic Global Warming in the Scientific Literature,” does not demonstrate that 97 percent of 12,000 scientific papers “presented evidence that humans are causing global warming,” nor does it establish a “consensus opinion” (i.e., that “human activity is very likely causing most of the current global warming”). Rather, Quantifying demonstrates only that a minority of scientists (10,188 of 29,083, or 35 percent) who wrote a minority of abstracts containing the words “global climate change” or “global warming” (3,894 or 32.6 percent) endorsed anthropogenic global warming. The majority of abstracts (7,930 or 66.4 percent), written by a majority of scientists (18,930), “expressed no position” on human activity as a cause of climate change. When the Quantifying authors disclose these 18,930 scientists’ positions on possible causes of global climate change, we might be in a better position to know whether a consensus exists and, if so, what that consensus is.
Elizabeth Harvey, Boise