clima e cibo: rapporto IIASA

["AlessandroGimona"<agimona@libero.it>]

Cari tutti, 
un importante rapporto dell International Institute for Applied Systems 
Analysis evidenzia che, se i modelli climatici sono corretti, la 
capacita' di produrre cibo in molti paesi del terzo mondo, gia' scarsa, 
scendera' ulteriormante, a volte di molto. Cio' chiaramente e' 
preoccupante per gli equilibri planetari.

spero interessi,
Alessandro Gimona

The report mentioned in the news item below is available off the IIASA 
web
site at:
   http://www.iiasa.ac.at/

 Ashwani
     Vasishth                    vasishth@usc.edu
         http://www-scf.usc.edu/~vasishth

 *****

http://www.latimes.com/news/nationworld/world/la-000056783jul11.story

Los Angeles Timse:
     July 11, 2001

THE WORLD
Warmer World Will Starve Many, Report Says
     Climate: A gathering of scientists is told that rising temperatures
are likely to boost crops in parts of the globe but devastate them in
others. 

USHA LEE McFARLING, TIMES SCIENCE WRITER 

AMSTERDAM -- Large-scale changes in the world's climate probably will
deepen the gap between the richest and poorest nations--potentially
crippling food production in parts of Africa, South Asia and South
America--according to the first worldwide assessment of food production
and climate change.

Forty of the world's poorest countries are likely to see major losses in
their ability to produce food--declines of up to 25%--if the climate
continues to warm substantially, according to the assessment, which was
released Tuesday at a major gathering of world climate scientists here.

The report emphasizes how differently global warming would affect 
various
parts of the world. Nations in tropical climates, including India, 
Brazil
and much of sub-Saharan Africa, would probably see huge losses in food
production, it says. More temperate climates, by contrast, could
experience large gains in crop yields as higher temperatures lengthen
growing seasons. Because nations in the tropics already are far poorer
than those in the world's north, the impact on them could be 
catastrophic,
with widespread starvation and malnutrition, the report projects. The
projections cover several decades, with the full impact hitting by 2080.

For the poorest nations, "there is no margin for loss," said Mahendra
Shah, one of the report's authors and a United Nations advisor and 
expert
on land use from Austria's International Institute for Applied Systems
Analysis.

"Many of these countries already have a food gap," he said, noting that
the 40 countries considered most at risk now cope with 450 million
malnourished people.

Globally, the report projects a small net increase in food production, 
but
the effects on different areas would be uneven. Though poor nations 
would
bear the heaviest burden as a group, some of the largest developing
nations--China, Indonesia, Mexico, Chile, Congo and Kenya, for
example--would probably see increased production.

Some developed countries, including Britain, the Netherlands and
Australia, could see crop yields decline as warmer, wetter weather
increases diseases and pests.

The overall impact on the United States--the world's largest emitter of
so-called greenhouse gases, which are believed to contribute to global
warming--is likely to be minimal, with possible small declines in the
ability to grow cereal grains, according to the report.

The report is unique because, although others have tried to estimate the
effect of climate change on individual countries, Shah and his 
colleagues
attempted to analyze food production worldwide. Their work takes into
account current climates, soil, terrain and land use.

The report comes as several developed countries, especially the U.S., 
are
balking at ratifying the Kyoto Protocol, which seeks to limit emissions 
of
greenhouse gases. One of the major arguments advanced by the Bush
administration and other critics of the treaty is that it does not 
require
developing countries to curb emissions.

The report's authors, however, assert that the developed countries, 
which
emit the bulk of greenhouse gases, must ratify the treaty to prevent 
more
suffering in poorer nations.

"The plight of the poorest countries must be at the center of
negotiations," Shah said. "They have no voice."

"The report raises issues of equity and fairness," said one of the
co-authors, Guenther Fischer. "The burden will undoubtedly fall
disproportionately on the poorest and most vulnerable."

Though many scientists here applauded the study and called it the most
thorough to date, it is not without its critics. Representatives of
industries that have opposed the Kyoto agreement said any attempts to
predict the effects of climate change on specific regions are 
notoriously
unreliable.

Climate "modeling capability is so poor, it makes it impossible to do
regional impacts. That right there calls the accuracy of the results 
into
question," said Glenn Kelly, executive director of the Global Climate
Coalition, a Washington-based group that represents business and 
industry.

Shah and his colleagues attempted to compensate for those uncertainties 
by
using three international models of climate change to predict how food
production would shift in this century.

Predictions differed slightly with each model, but under each, 
"developing
countries lose as a group," Shah said. "Developed countries gain."

In nations close to the equator, crop losses would come as plants are
stressed by heat and weakened by disease. Other declines could come as
some regions dry out as a result of decreased rainfall and increased
evaporation.

Robert Watson, chairman of the U.N.'s Intergovernmental Panel of Climate
Change, said factors ranging from increased population to changes in 
land
use will exacerbate the effects of climate change in struggling nations.

"Climate change is not simply an environmental issue," he added. "It is 
a
development issue."

Yvo de Boer, a Dutch environment minister who is among the European
leaders seeking to resuscitate the dying Kyoto Protocol, argued that
developing countries should not be expected to do as much as developed
countries to reduce emissions because they don't have the financial or
technological resources and have historically contributed a small amount
of greenhouse gases to the atmosphere.

"Damage caused by climate change exacerbates the inequities that already
exist," De Boer said. Developing countries "are the first hit and the
least able to defend themselves." 


Alessandro Gimona
agimona@libero.it