Climate change raises risk of hunger – scientists

By Patricia Reaney

DUBLIN (Reuters) – About 50 million more people, most of
them in Africa, could be at risk of hunger by 2050 due to
climate change and reduced crop yields, scientists predicted on
Monday.

Roughly 500 million people worldwide already face hunger
but rising levels of greenhouse gases could make the problem
worse.

“We expect climate change to aggravate current problems of
the number of millions of people at risk of hunger, probably to
the tune of 50 million,” said Professor Martin Parry of the
Hadley Center of the UK Meteorological Office.

“The greatest proportion, about three-quarters of that
number, will be in Africa.”

Parry told the British Association science conference that
it would take huge reductions in emissions of greenhouse gases
– about 20 times those required by the Kyoto Protocol — to
avoid the additional risk of hunger.

The 1997 protocol demands cuts in greenhouse emissions by
5.2 percent below 1990 levels by 2008-12.

The United States, the world’s biggest polluter, has
refused to back the protocol, saying it would hurt its economy.
It also believes the pact is flawed because it omits rapidly
industrializing emerging economies such as India and China.

In a separate presentation at the meeting Professor Steve
Long noted that although it is widely recognized that climate
change will decrease the yield of crops, a rise in CO2, which
is a major driver of global warming, will increase plant
growth.

“So as you increase carbon dioxide, plant growth is
actually boosted,” said Long, from the University of Illinois
in the United States.

But in field experiments Long and his colleagues found that
the yield increase due to carbon dioxide is only about half of
what is predicted and for corn there was no increase at all.

He added that a second change in the atmosphere — rising
levels of ozone in the northern hemisphere — further
complicates the picture because there have been experiments
that have suggested this would decrease crop yields.

“We’ve conducted, in Illinois, the first of these
experiments in the open field situation. In fact, we find that
with our soya bean crops that the elevation to the levels
expected by 2050 decrease the yield by about 15 percent,” he
explained.

“So that would cancel out any stimulation due to carbon
dioxide. We think these new experiments suggest that as bad a
picture as Martin (Perry) presented, actually the reality may
be even worse.”