Is the global heatwave danger increasing?

Is the global heatwave danger increasing?
17 January 2013

Measurements from around the world suggest monthly temperature extremes have become much more frequent, according to a new report from the Potsdam Institute for Climate Impact Research (PIK) and the Complutense University of Madrid.

There are now five times as many record-breaking hot months on average worldwide than could be expected without long-term global warming, the study adds.

In parts of Europe, Africa and South Asia the number of monthly records has increased by a factor of ten.

“The last decade brought unprecedented heatwaves; for instance in the US in 2012, in Russia in 2010, in Australia in 2009, and in Europe in 2003,” says lead author Dim Coumou.

“Heat extremes are causing many deaths, major forest-fires, and harvest losses – societies and ecosystems are not adapted to…record-breaking temperatures.”

Lethal heatwaves have become an important humanitarian concern for the Red Cross Red Crescent worldwide over the past decade – including temperate developed nations like France and the Netherlands.

The PIK study was compiled before the current record-breaking heatwave in Australia, where the Red Cross has been supporting people affected by bush fires in Tasmania, New South Wales, Victoria and the Northern Territory.

The Australian government’s Climate Commission earlier this week reported that the “length, extent and severity of the…heatwave is unprecedented in the measurement record.

“Although Australia has always had heatwaves, hot days and bushfires,” the Commission’s report added, “climate change is increasing the risk of more frequent and longer heatwaves [and] has contributed to making the current extreme heat conditions and bush fires worse.

“Good community understanding of climate change risks is critical to ensure we take appropriate action to reduce greenhouse gas emissions and…respond to extreme weather.”

The past year in the UK, meanwhile, has been “the second wettest on record,” according to the British Met Office.

British Red Cross volunteers were out in force over the Christmas holidays to assist people affected by disastrous floods countrywide.

The National Society’s website now carries detailed advice for householders on what to do before, during and after floods.

“All this reinforces a now-familiar pattern of rising risk and uncertainty,” says Dr Maarten van Aalst, director of the Climate Centre and Coordinating Lead Author of the 2011 report on extremes and disasters by the Intergovernmental Panel on Climate Change.

“The most important reasons for rising disaster-risk are related to the vulnerability and exposure of people,” he adds. “But combine this with increases in extreme weather and there’s reason to be especially concerned.

“In short, we have to be more ready than ever before – including for deadly heatwaves in places without much experience of them.”

Temperatures in the Australian heatwave rose so high that the country’s Bureau of Meteorology had to introduce two new colours on its charts for temperatures above 50C. (Graphic: Australian Bureau of Meteorology)