Rio de Janeiro, Brazil
Augsut 27, 2008
Catarina Chagas,
SciDev.Net
Brazil's agriculture could be severely affected by climate
change, with soya hardest hit by rising temperatures, report
Brazilian scientists.
They based their projections on climate models developed by the
UK Met Office's Hadley Centre for Climate Prediction and
Research.
The researchers considered two possible scenarios for the
future: an optimistic one, with a 1.4–3.8 degrees Celsius
temperature rise by 2100, and a pessimistic one, with a rise
from 2–5.4 degrees Celsius.
They modelled the impact of such temperatures on agricultural
land and their effect on Brazil's nine most important crops —
cotton, rice, coffee, sugar cane, beans, sunflower, cassava,
maize and soya.
Under the most optimistic scenario, by 2020, six of Brazil's
food crops — rice, coffee, beans, cassava, maize and soya —
could have dropped in value by a total of 6.7 billion Brazilian
reals (US$4 billion).
The rise in temperature will increase the loss of water through
evaporation from soil and plant transpiration, reducing
crop-growing areas particularly in northeast Brazil.
Soya will be the most threatened, with land suitable for soya
cultivation predicted to drop by about 20 per cent by 2020 and
40 per cent by 2070, even under the optimistic scenario.
But sugar cane cultivation could double in a few decades because
of the crops' ability to adapt to higher temperatures and
increases in carbon dioxide.
"Sugar cane plantations will benefit with future scenarios,
increasing ethanol production. However, essential crops for the
internal market and population nutrition will suffer, bringing a
high social cost," Hilton Silveira Pinto, one of the report's
authors and a senior researcher at the State University of
Campinas (Unicamp), told SciDev.Net.
He adds that the most pessimistic scenario will only be realised
if there are no efforts to mitigate climate change and minimise
the impact of rising temperatures by modifying production
techniques.
Suggestions to minimise impacts include better use of soil by
alternating grazing and planting land, encouraging the
production of crop varieties adapted to drought and genetic
improvement of plants.
The report was released this month (11 August) by the Unicamp,
the Brazilian Agricultural Research Corporation, and the Center
for Weather Prediction and Climate Studies.
The researchers will now analyse the impact of global warming on
other crops and livestock, and social impacts from the change in
agriculture. A new report will be released in 2009. |
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