Global warming will cut crop harvests by 2% each decade

Oliver Milman in the Guardian (UK): Climate change will cause bigger falls in crop yields than previously thought, exacerbating food insecurity, a new study has found. The research, conducted by Australian, British and American scientists, found that the situation will worsen in the second half of the century, with tropical areas worse hit than temperate regions.

An analysis of more than 1,700 simulations found that across all regions and all crops, including wheat, maize and rice, yields will drop by 2% each decade, based on a 2C rise by 2050. However, for some crops, the situation will be much worse, with wheat and maize in tropical areas experiencing a 40% decline if temperatures reach 5C warmer than pre-industrial levels.

Governments have agreed a target of limiting temperature rise to 2C above pre-industrial levels, although scientists warn the planet could experience a 4C or even 5C rise if carbon dioxide emissions are not drastically cut.

The report’s co-author Dr Mark Howden, of the CSIRO, said the situation was worse than previously thought. “We looked at a whole range of temperature and rainfall scenarios and found results that were distinctly far more negative than the previous IPCC report,” he said.

A wheatfield in Ukraine, near Lviv, shot by Raimond Spekking, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license