The Intergovernmental Panel on Climate Fhange (IPCC) recently issued a 582 page report on what is known about the impact that global warming could have on nine different extreme-weather events. The report explores ways to reduce the risk to people and property from weather extremes. It focusses on helping communities adapt to long-term global warming. It signals a major change in the thinking about adaptation to climate change. Avoided as recently as a decade ago, adaptation no longer is seen merely as diverting attention from emission reduction. Researchers now know that even if CO2 emissions were to cease today, climate warming would continue because CO2 remains in the atmosphere for centuries.
Identifying the impacts of extreme weather on the climate is challenging, but scientists have begun the process over the past 60 years of collecting consistent, high quality observations over long periods of time and broad spatial coverage. The confidence levels are highest for trends in extreme temperatures; lower for extreme precipitation. Many of the approaches communities and countries can take are “low regrets measures,” which will provide significant benefits whatever underlies extreme-weather events. The cost of such events has been rising. Between 1970 and 1989, losses from all types of disasters averaged $5 billion a year globally. Since 1989, the average is $30 billion. Last year, it was $35 billion just in the U.S. Globally, losses from severe weather were $61 billion. Not all, or even most, of the increase is due to global warming; other factors include rapid population growth, increased wealth in vulnerable areas, and failure to take appropriate adaptive measures.