GLOBAL WARMING……COULD DEVASTATE CROPS

[Anonymous]

Climate ‘could devastate crops’

The work can help prioritise investment, say the authors

Climate change could cause severe crop losses in South Asia and
southern Africa over the next 20 years, a study in the journal Science
says.

The findings suggest southern Africa could lose more than 30% of its main crop, maize, by 2030.

In South Asia losses of many regional staples, such as rice, millet and maize could top 10%, the report says.

The effects in these two regions could be catastrophic without effective measures to adapt to climate change.

The majority of the world’s one billion poor depend on
agriculture for their livelihoods. Yet, said lead author David Lobell,
it is also “the human enterprise most vulnerable to climate change”.

The researcher, from Stanford University in California,
US, added: “Understanding where these climate threats will be greatest,
for what crops and on what timescales, will be central to our efforts
at fighting hunger and poverty over the coming decades.”

‘Crushing’ losses

The study used computer models to assess the impact of
climate change on farming in 12 world regions where the bulk of the
world’s malnourished people live. This included much of Asia,
sub-Saharan Africa, the Caribbean and Central and South America.

“To identify which crops in which regions are most under
threat by 2030, we combined projections of climate change with data on
what poor people eat, as well as past relationships between crop
harvests and climate variability,” Dr Lobell explained.

The scale and speed of the effects on agriculture surprised the scientists.

“For poor farmers on the margin of survival, these
losses could really be crushing,” said co-author Marshall Burke, also
of Stanford University.

All the models agree that there will be adverse effects
on maize in southern Africa and rice in South-East Asia, but the
picture is less certain in other areas such as parts of West Africa
where it is unclear how global warming will impact the local climate.

Early investment

“For these regions, you get half of the climate models
telling you it’s going to get wetter and the other half giving you the
opposite,” said Dr Burke.

“As a result, our study raises the potential for very
bad impacts in these regions but with much less certainty than in other
regions.”

A few developing regions, such as the temperate
wheat-growing areas of China, could actually benefit in the short run
from climate change, he added.

Since it typically takes 15 to 30 years for major
agricultural investments to be fully realised, work must start soon to
help subsistence farmers increase their yields or switch crops, the
study says.

While relatively inexpensive changes, such as switching
crops or altering planting seasons, could trim the losses, “the biggest
benefits will likely result from more costly measures, including the
development of new crop varieties and expansion of irrigation,” the
authors wrote.

[Author]

February 1, 2008 at 2:23 PM