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The scare: In an official press release of the Royal Society, Britain’s oldest taxpayer-funded body, Martin Rees, its president, is quoted as saying: “The science of climate change is complex; however the weight of scientific evidence shows that ‘global warming’ caused by human actions is happening now …”
The truth: The weight of scientific evidence shows that “global warming” began 300 years ago, at the end of an unusually prolonged period of comparative solar inactivity known as the Maunder Minimum, and has continued since then at a near-uniform 1 F per century. Throughout most of that long period of warming, we were not numerous enough or industrially active enough to have made any impact on mean global surface temperatures whatsoever (Akasofu, 2007). The last year which set a record for mean global surface temperature was 1998, when an exceptional but not unprecedented El Nino Southern Oscillation caused a sharp spike in global temperatures as stored heat was released from the world’s oceans to the atmosphere. Note that the instrumental temperature record began only in 1880; and, given the long-run rising trend in global temperatures, higher temperatures at the end of the period of record are scarcely surprising.
Since 1998 no new annual temperature record has been set. Since late 2001, linear-regression trends for all four of the major global-temperature datasets have been downward (Figure 1). The drop in temperature between January 2007 and January 2008 was the greatest since instrumental records began in 1880. Whatever else is happening in the climate, “global warming” is not “happening now” and has not been happening for a decade. No new annual global-temperature record is expected until 2015 (Keenlyside et al., 2008). Not one of the computer models predicted this long period of global cooling. In the month of June 2008, exactly 20 years after James Hansen’s forecast to Congress that global temperatures would rise sharply, global temperatures were actually cooler than they had been when he made the forecast in June 1988.