   |
|
afrol.com, 31 August - Global warming could fundamentally alter one third of plant and animal habitats by the end of this century, and cause the eventual extinction of certain plant and animal species, according to a new study released today by WWF, the conservation organization. Although having most effect in colder climates, several African habitats also are affected. The report 'Global Warming and Terrestrial Biodiversity Decline', says that in the northern latitudes of Canada, Russia and Scandinavia, where warming is predicted to be most rapid, up to 70 percent of habitat could be lost. Russia, Canada, Kyrgystan, Norway, Sweden, Finland, Latvia, Uruguay, Bhutan and Mongolia are likely to loose 45 per cent or more of current habitat while many coastal and island species will be at risk from the combined threat of warming oceans, sea-level rise and range shifts. Species most at risk are those that are rare or live in isolated or fragmented habitats. They include the rare Gelada baboon in Ethiopia, the mountain pygmy possum of Australia, the monarch butterfly at its Mexican wintering grounds, and the spoon-billed sandpiper at its breeding sites in Russia's arctic far east. In the Untied States, most of the northern spruce and fir forest of New England and New York State could ultimately be lost. In patches of habitat that do survive, local species loss may be as high as 20 per cent in the most vulnerable mountain ecosystems such as northern Alaska, Russia's Tamyr Peninsula and the mountainous Lesotho. Lesotho is heading the list over countries, ranked according to percent species loss as predicted due to the decrease in the area of persisting habitat patches. Some 5,4% losses were calculated. On fourth place, Guinea-Bissau is found (2,9%). Lesotho and other parts of the Drakensberg Mountains of South Africa have and "island habitat" as their climate is alpine in the midst of an otherwise Mediterranean and sub-tropical climate. Warming could therefore extinguish an entire climate zone in the mountains, and with it, its endemic species. Guinea-Bissau, with its low altitude above sea level, mangrove coast and islands, stands the risk of loosing much of its territory due to the rising of sea level (see map). Also Zambia is found on the top-20 list of affected countries worldwide (2,4%).
"As global warming accelerates, plants and animals will come under increasing pressure to migrate to find suitable habitat. Some will just not be able to move fast enough," said Adam Markham, Executive Director of a US NGO, Clean Air-Cool Planet, one of the co-authors of the report. "In some places, plants would need to move ten times faster than they did during the last ice age merely to survive. It is likely that global warming will mean extinction for some plants and animals." The report's predictions are based on a moderate estimate that concentrations of carbon dioxide (CO2) in the atmosphere will double from pre-industrial levels during this century. However, some projections suggest a three-fold increase in concentrations by 2100 unless action is taken to rein in the inefficient use of coal, oil and gas for energy production. In this case, the effects on nature could be even more dramatic. Already, Costa Rica's golden toad has probably become extinct. Birds such as the great tit in Scotland and the Mexican jay in Arizona are beginning to breed earlier in the year; butterflies are shifting their ranges northwards throughout Europe; and mammals in many parts of the Arctic - including polar bears, walrus and caribou - are beginning to feel the impacts of reduced sea ice and warming tundra habitat. "This is a wake-up call to world leaders - if they do not act to stop global warming, wildlife around the globe may suffer the consequences. World leaders must give top priority to reducing levels of carbon pollution. They must not miss the chance of this November's climate summit for stepping up action and preventing a catastrophe that could change the world as we know it," said Jennifer Morgan, Director of WWF's Climate Change Campaign. The entire report Global Warming and Terrestrial Biodiversity Decline, by Professor Jay R Malcolm and Adam Markham (commissioned by WWF, published by WWF International, August 2000) can be downloaded from WWF on this link.
|
