Climate change will hit yields

NEW RESEARCH indicates that climate change will result in substantial reductions in food crop yields in tropical countries.

A two-day international meeting of scientists started on Tuesday (April 26) in London, where research results were presented.

Large-scale field experiments have shown that the effects of increased temperatures, drought and ground-level ozone concentrations will outweigh the beneficial fertilisation effects of rising levels of atmospheric carbon dioxide.

Steve Long from Illinois University said: “Growing crops much closer to real conditions has shown that increased levels of carbon dioxide in the atmosphere will have roughly half the beneficial effects that were previously hoped for in the event of climate change.”

“In addition, ground-level ozone, which is also predicted to rise but has not been exensively studied before, has been shown to result in a loss of photosynthesis and 20% yield loss,” Prof. Long said.

Tim Wheeler, of the University of Reading, told the BBC that the effects of climate change are likely to differ between climate zones, with tropical countries being the worst hit.

By 2050 yields are likely to increase somewhat across Europe and in Canada, while tropical countries, which produce most of the world’s food today, are likely to see decreases, Dr Wheeler said.