April 29, 2005
Catherine
Brahic, SciDev.Net
Global warming over the next 50
to 80 years could jeopardise food security for the world's
poorest people, warn scientists.
Extreme climate conditions —
such as floods and droughts — resulting from global warming
could greatly damage crop yields in developing countries, they
explained.
The researchers were addressing
a gathering of climatologists, policymakers, economists and
sociologists at the Royal Society, the United Kingdom's science
academy.
Martin Parry, co-chair of a
working group of the Intergovernmental Panel on Climate Change,
said that although global figures appear to suggest that food
security is not at risk, they hide regional differences.
Locally, the risk to food
production is much greater said Parry, particularly in Asia but
even more so in Africa — a view all delegates agreed with.
Global warming threatens crops
in several ways. Rising sea levels threaten to flood fields in
low-lying coastal areas, such as those in Bangladesh and Egypt.
In sub-Saharan Africa, crop
yields are expected to fall in regions predicted to become
hotter and drier.
Researchers are also concerned
that climate change could reduce the farming workforce by
increasing the area in which malaria is endemic.
But simply identifying the
threat to food security is not enough, said Tony Nyong of the
University of Jos, Nigeria. What we need, he says, is the answer
to the question "If the crops fail, what do you do about it?"
The delegates discussed
approaches of reducing or adapting to the effects of climate
change to ease the threat to food security.
Lin Erda of the Chinese Academy
of Agricultural Sciences suggested that China could adapt to
climate change and boost crop yields using 'carbon dioxide
fertilisation', where the gas is pumped into greenhouses.
However, his data also showed
that carbon dioxide fertilisation decreased the protein content
of wheat.
Reducing the threat to the
global water supply, said Parry, will require reducing carbon
dioxide emissions far more than what is required by the Kyoto
Protocol on climate change.
By and large, however,
delegates agreed on the need to adapt to the effects of climate
change in ways that would offset the threat to food security.
Parry said this was not a
question of devising new technologies, but making adequate use
of existing ones.
"We could mop up the decline in
crop productivity with adaptation measures," said Parry. "But
then, we could also mop up the problem of those who are dying of
hunger now. We don't but we could."
The meeting's conclusions will
be presented at July's G8 summit of leaders of the world's most
industrialised nations.
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