The Climate Extremists
COPENHAGEN – Extreme weather is often said to be one of the main reasons for taking firm action on global warming. Nowadays, 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. In 2007, the United Nations’ Intergovernmental Panel on Climate Change (IPCC) released a report on climate extremes that received considerable media attention. But, two years later, it was discovered 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. For example, according to the IPCC, sea levels will rise by a relatively manageable 18-59 centimeters (7-23 inches) by the end of the century, whereas news organizations and activists regularly claim that we should expect sea levels to rise by meters.