The study behind this headline is from the Met Office's Hadley Centre for Climate Prediction and Research, by Eleanor Burke and two Hadley Centre colleagues. It models how a measure of drought known as the Palmer Drought Severity Index (PDSI) is likely to increase globally during the coming century with predicted changes in rainfall and heat around the world because of climate change.
This is, of course, a study, and as such it contains uncertainties: there is only one climate model involved, one future scenario for emissions of greenhouse gases (a moderate-to-high one) and one drought index. It will be the basis for further studies, however:
The findings represent the first time that the threat of increased drought from climate change has been quantified with a supercomputer climate model such as the one operated by the Hadley Centre.
Their impact is likely to be even greater because the findings may be an underestimate. The study did not include potential effects on drought from global-warming-induced changes to the Earth's carbon cycle.
In one unpublished Met Office study, when the carbon cycle effects are included, future drought is even worse. (My added emphasis.)
In this future scenario areas that are already suffering the effects of drought will face the loss of even subsistence agriculture with consequent mass starvation, and the wave of environmental refugees will sweep across the earth.
One of Britain's leading experts on the effects of climate change on the developing countries, Andrew Simms from the New Economics Foundation, said: "There's almost no aspect of life in the developing countries that these predictions don't undermine - the ability to grow food, the ability to have a safe sanitation system, the availability of water. For hundreds of millions of people for whom getting through the day is already a struggle, this is going to push them over the precipice."
(...)
"We're talking about 30 per cent of the world's land surface becoming essentially uninhabitable in terms of agricultural production in the space of a few decades," Mark Lynas, the author of High Tide, the first major account of the visible effects of global warming around the world, said. "These are parts of the world where hundreds of millions of people will no longer be able to feed themselves."
Mr Pendleton said: "This means you're talking about any form of development going straight out of the window. The vast majority of poor people in the developing world are small-scale farmers who... rely on rain."
Lest you think this is only going to affect poor people in the developing world, places like Kenya and Brazil, you might consider the fact that much of the mid- and south west, as well as a large portion of the southeast of this country are currently in drought conditions. The drought has mitigated somewhat as fall approaches, but for most of the summer this map was a worrisome thing to read.
Even the land we think of as cool, grey and rainy, England itself, will not be immune from this encroaching heat and drought, as evinced in this article from the same environment page of The Independent: Summer Heatwaves May Get Much Worse. No relief will be found by planning a summer abroad if this becomes reality:
Climate change could send heatwave temperatures in the South-East of England soaring as high as 46C (114.8F) by the end of the century, the Met Office has warned.
So, if that's the prediction for the SouthEast of the green and pleasant land of England, what will things be like in Arizona? Nevada? Kansas? South Dakota? Bear in mind this is a process that will be relentlessly taking place over the years between now and the end of the century. Negotiations will be taking place in Nairobi in November on a successor to the Kyoto climate treaty and the Hadley study will be presented there. It might be time we put a great deal more pressure on the United States to join Kyoto. There's a great deal at stake here for the future of the planet.
