The passages quoted below are from an opinion piece by retired physicist Jack Kasher who was a colleague of mine at the University of Nebraska at Omaha.
I was pleased to see that the Millard school district pulled Laurie David’s book, “The Down-to-Earth Guide to Global Warming,” due to “a major factual error” in a chart that shows rising temperatures and carbon dioxide levels dating back 650,000 years. The chart claims to show that global warming is caused by increases in carbon dioxide levels, but the facts show that this is not the case.
In May, I attended an international conference on global warming in Chicago, with 73 speakers from 23 countries. The book and its erroneous chart were discussed there. (Go online to http://www.heartland.org/events/2010Chicago/index.html and click on “proceedings” to see most of the talks and PowerPoint presentations.)
When the error is corrected, the chart will show that in every single case over this time span the Earth warmed up first, followed by a later increase in carbon dioxide. This is clear proof that in the past global warming was not caused by an increase in CO2. If anything, it is the other way around. In each instance, something other than CO2 caused the temperature increase, which then might have made the CO2 rise. This chart shows that past history actually contradicts David’s main assumption in her book — namely that man-made carbon dioxide is causing global warming.
For the full commentary, see:
Dr. Jack Kasher. “Midlands Voices: Let’s include uncertainties in global-warming lessons.” Omaha World-Herald (Wednesday June 30, 2010): ??.