Agence France Presse
GENEVA, Feb 13 (AFP) - Global warming could threaten food security, especially in poor tropical countries, the United Nations' top panel of climate experts says in a draft report.
The document also warns that atmospheric warming could unleash violent storms, extreme droughts and floods, inflicting costs that will damage the global economy.
Agriculture around the world will be affected by global warming, raising major worries about ensuring food supplies for the planet's burgeoning population, say the experts, a working group of the UN's Inter-governmental Panel on Climate Change (IPCC).
In the US Great Plains and the Canadian Prairies -- the world's bread basket -- production is likely to decline because of drier soils and heatwaves, they warn.
Crop production in more northerly latitudes, such as northern Canada, may in fact improve because of warmer temperatures, but at the same time there could be a higher risk of insect pests, they say.
"In the tropics, where some crops are near their maximum temperature tolerance and where dryland agriculture predominates, yields would decrease generally with even minimal increases in temperature.
"Where there is a large decrease in rainfall, crop yields would be even more adversely effected," they add.
The working group began to look at the draft at a meeting here Tuesday. It was expected to endorse its major lines on Friday, ahead of publication next Monday.
Tasked with evaluating the impact of climate change, it is one of three working groups whose contributions will be published by the IPCC this year, providing its first update about the state of knowledge about global warming.
Last month, the IPCC's first working group completed a huge study on scientific aspects of the phenomenon, which grimly concluded that the Earth's atmosphere was warming faster than previously thought.
It estimated a rise of up to 5.8 C. (10.4 F.) by 2100 as a result of releasing billions of tonnes of carbon dioxide (CO2) gas by burning fossil fuels -- a "greenhouse effect" that causes the Sun's heat to be stored up in the lower atmosphere.
Those figures, says the draft Geneva document, translate into big changes in climate that will affect almost every range of human activity.
If the warming is in the range of 2 to 3 C. (3.6 to 5.4 F.), that could shave "a few percent (from) global GDP" (gross domestic product), but higher temperatures would result in even higher losses, it predicts.
Among the predicted repercussions are these:
- HUMAN SETTLEMENT: Flooding and landslides, and in coastal areas, higher sea levels will be among the hazards of climate change. Depending on the increase in temperature, there will also be a higher risk of violent weather events, such as storms, cyclones and droughts. The human and economic toll will rise, mainly because of increasing settlement in exposed areas.
- WATER: A third of the world's population, or 1.7 billion people, already live in countries that are water-stressed, a figure expected to rise to five billion by 2025. "Climate change would decrease the available water in many of these countries, particularly in central Asia, southern Africa and countries around the Mediterranean Sea."
- HEALTH: There could be "a small net increase" in mosquito-borne diseases such as malaria and dengue fever. Urban populations will face more frequent heatwaves, higher humidity and, in many cities, worse air pollution, placing the elderly and the sick at risk. Diminished crop yields in the most vulnerable countries will also have an impact on nutrition.
The working group says that the world's poorest countries will bear the brunt of global warming, both in terms of its effect on their local climate and in their poor resources, financial and human.
Coping with climate change requires "wealth, technology, education, information, skills, infrastructure, access to resources, and stability and effectiveness of institutions," it says.
"Populations and communities are highly variable in their endowments with these attributes, and the least developed countries are generally poorest in this regard."
The third working group report, outlining recommendations for easing climate change, is to be published next month.:
