Tim Radford. An excerpt from Climate News Network August 14, 2013
European climate scientists say the greenhouse gases already in the atmosphere mean it is inevitable that far more parts of the world will experience more frequent and severe heat waves in the next 30 years.
LONDON, 15 August – Stand by for extreme weather. Prepare for heat waves on a scale that was once unprecedented. For once, there is no “if” in the forecast. Even if governments abandon fossil fuels everywhere, immediately and invest only in green energy, there will be new record temperatures.
The greenhouse gas emissions of the last few decades now mean that regions of the planet subjected to extreme heat will double by 2020 and quadruple by 2040.
Dim Coumou of the Potsdam Institute for Climate Impact Research in Germany and a colleague from Madrid in Spain make this prediction in Environmental Research Letters. In essence, they are only pointing out that the unprecedented heat waves that have already been recorded this century in Australia, the US, Russia, Greece and so on will increase in frequency and extent and in degrees Celsius.
They have followed the mathematical logic of climate models and simple thermodynamics. Extra greenhouse gas already in the atmosphere has pushed up global average temperatures. But an average is only the sum of all the extremes divided by the days in the year.
And as average temperatures rise in response to carbon dioxide levels, so will the extremes. And their forecast says the second half of the century will be even worse – unless global greenhouse emissions are reduced substantially.
“In many regions, the coldest summer months by the end of the century will be hotter than the hottest experienced today – that’s what our calculations show for a scenario of unabated climate change. We would enter a new climatic regime”, said Dr Coumou.
Such warnings are not new: the World Meteorological Organisation made similar predictions in July, and the first years of this century have been marked by dramatic spells of record-breaking heat. In Russia in 2010, for instance, the temperature in July went up by 7°C to a daily peak of 40°C in Moscow.
Right now, 5% of the land area of the planet has experienced heat extremes, that is, temperatures far beyond the normal for summer at that latitude: temperatures that spell out deaths from heat stroke or heat exhaustion, harvest loss, devastating drought and forest fires.
By 2020 the area at risk will reach 10%, and by 2040, one fifth of the land area of the planet will be experiencing extreme temperatures at some point in the summer, just because of the extra energy already in the planetary system. “There’s already so much greenhouse gas in the atmosphere today that the near-term increase of heat extremes seems to be almost inevitable”, says Coumou.
Editor’s Note; Having just seen the new Matt Damon flick, ELYSIUM, set in the near-future where the SuperRich have escaped the planet to live on a climate-controlled space colony while the 99% broil down below on a polluted, heat-stressed planet subject to police-state oppression, the projection of heat extremities hit home. We can’t help thinking that not long ago when it may have still been possible to take steps to avoid Hell-on-Earth, prudent change was stymied to protect the profits of the Oil-Coal Industry & its owners. When you’re gasping for your last breath, just remember whose sins you and your children are dying for.