Global warming activists like to cite extreme weather as one of the main reasons that we must take firm action on global warming. No hurricane or heat wave passes without a politician or activist claiming it as evidence of the need for a global climate deal, like the one that just got postponed until the end of the decade in Durban, South Africa.
Such claims merit close scrutiny. A 2007 report by the U.N. Intergovernmental Panel on Climate Change received considerable media attention. But it was discovered two years later that some of the IPCC report’s key claims—for example, that global warming would cause the immense Himalayan glaciers to disappear by 2035 or halve African crop yields by 2020—were based on statements made in appeals by environmentalist organizations and were backed by little or no evidence.
Despite this error, the IPCC has long been a fairly reliable source of sensible and responsible estimates in an otherwise histrionic debate. Unfortunately, sensible estimates are not breaking news. Whereas the IPCC predicts that sea levels will rise by a relatively manageable 7 to 23 inches by the end of the century, news organizations and activists regularly claim that we should expect sea levels to rise by meters.
The media similarly misrepresented the findings of the IPCC’s 2010 report on climate extremes. Sweden’s most prestigious daily newspaper, Svenske Dagbladet, filled almost an entire Sunday front page with an eviscerated body showing exposed arteries, adorned with the warning: “Ever warmer climate threatens more death.” Across two full pages inside, the paper presented a graph of seasonal deaths over the past decade and showed how summer heat waves have killed dozens of Swedes. Yet, even a cursory reading of the graph showed clearly that many more people die from cold than from heat.
The IPCC report did indeed state that global warming would mean more extreme warm temperatures, but it also pointed to fewer extreme cold temperatures. Because more people almost everywhere on the planet die each year from cold temperatures than from warm temperatures, the overall impact of global warming will be fewer deaths from temperature extremes. Indeed, according to one estimate, by midcentury, about 400,000 more people will die from heat than would have perished at current temperatures, but 1.8 million fewer people will die from cold. Unfortunately, nondeaths are a nonstory.
In November, the Christian Science Monitor focused on the IPCC’s findings on hurricanes, the strength and frequency of which have been linked to global warming ever since former Al Gore’s film An Inconvenient Truth made media hay out of Hurricane Katrina. The Monitor’s headline blared: “Climate change warning: Brace for hotter heat waves, stronger storms.” Yet, while the IPCC suggests that hurricanes’ maximum wind speeds will most likely increase, it also predicts that the total number of tropical hurricanes may fall, and that extra-tropical hurricanes will most likely decline in frequency, too.
The IPCC clearly states that hurricane-damage costs have increased steadily because more people, with more expensive property, now live where hurricanes strike. Population, exposure, and vulnerability, not greenhouse gasses, are the main factors underlying future damage as well.