quarta-feira, 8 de setembro de 2010

Studies: Climate change threatens bees, flowers, food

By Alexey Sazonov, AFP/Getty Images
Climate change could threaten the pollination of plants and the watering of crops, both of which could affect food security, according to two studies released this week.

New Canadian research suggests climate change may be causing flowers to open before bees wake up from hibernation, so the bees don't get early nectar and the flowers aren't pollinated. The findings could apply to a wide range of flowering plants such as tomatoes and strawberries.

By David Silverman, Getty Images
"Bee numbers may have declined at our research site, but we suspect that a climate-driven mismatch between the times when flowers open and when bees emerge from hibernation is a more important factor," study author James Thomson, a professor of ecology and evolutionary biology at the University of Toronto, told the Ottawa- Citizen. He started studying wildflowers 17 years ago on remote land in Colorado's Rocky Mountains, measuring their changes three times a year.

In Stockholm, Sweden, a different report this week reveals how food security worldwide could be threated by erratic rainfall related to climate change. Experts meeting there for the World Water Week conference cite drought in Russia and floods in Pakistan as examples of unpredictable rainfall.

Africa and Asia are likely to be hardest hit, because most of their crops are not irrigated, according to the report by the International Water Management Institute. In Asia, it says, about 66% of agriculture depends on rainfall and in sub-Saharan Africa, 94% does.

"We are getting to a point where we are getting more water, more rainy days, but it's more variable, so it leads to droughts and it leads to floods," Sunita Narain, the head of the Centre for Science and Environment in India, told Agence France-Presse. "Climate change is making rainfall even more variable."

Her comments came as Pakistan recovers from devastating floods and Russia from a record-hot summer and drought that destroyed a quarter of its crops.

Jan Lundqvist, who chairs the Stockholm International Water Institute's Scientific Programme Committee, hesitates to blame global warming for extreme weather shifts. "These kinds of fluctuations are part of human history," he tells AFP, "but climate change is probably making them more extreme."

Fonte: http://content.usatoday.com/communities/greenhouse/post/2010/09/climate-change-threatens-bees-flowers-food/1

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