BIODIVERSITY: The Amazon Is Not Eternal
The Amazon jungle "is very close to a tipping point," and if destruction continues, it could shrink to one third of its original size in just 65 years, warns Thomas Lovejoy, world-renowned tropical biologist
By Stephen Leahy* | InterPress Service | Feb 2, 2010
Urban encroachment on the Amazon (Credit:Public domain)
Climate change, deforestation and fire are the drivers of this potential Amazonian apocalypse, according to Lovejoy, biodiversity chair at the Washington DC-based Heinz Centre for Science, Economics and the Environment, and chief biodiversity adviser to the president of the World Bank.
Lovejoy laid out the scenario for participants at the Biodiversity Science Policy Conference in Paris last week, sponsored by UNESCO (United Nations Educational, Scientific and Cultural Organisation), and marking the beginning of the U.N.'s International Year of Biodiversity.
"The World Bank released a study that finally put the impacts of climate change, deforestation and fires together. The tipping point for the Amazon is 20 percent deforestation," and that is "a scary result," Lovejoy told Tierramérica in an interview.
The study, "Assessment of the Risk of Amazon Dieback," released Jan. 22, drew on the expertise of several international research institutions, including Japan's Meteorological Research Institute, Britain's Exeter University, Brazil's Centre for Weather Forecasting and Climate Change (CPET/INPE), Germany's Potsdam Institute and Earth3000.
The results and analysis were reviewed by an international blue-ribbon panel of scientists.
Lovejoy, head of the committee responsible for this major scientific investigation, said the Amazon has already lost 17 to 18 percent of its forests. Furthermore, "it has a remarkable hydrogeological system where the forest generates at least half of its own rainfall."
This literally means the rainforest makes its own rain, but it also brings rainfall to many areas outside of the Amazon, including the central-western Brazilian state of Mato Grosso and northern Argentina, he said.
What the study shows for the first time is the combination of global warming on a path to reach two degrees Celsius, deforestation of roughly 20 percent of the original forest, and forest fires that undermine the Amazon's unique hydrogeological system.
The Amazonian south and southeast will receive much less rainfall. Less moisture means those areas will be more prone to fires, which not only destroy the forest but also further dry out the surrounding forest - all of which reduces the Amazon's ability to produce rain. The process becomes a self-reinforcing feedback loop.
"The forest eventually converts to cerrado (the Brazilian savanna) after a lot of fire, human misery, loss of biodiversity and emission of carbon into the atmosphere," said Lovejoy.
The Earth's average temperature has already warmed 0.8 degrees Celsius since the pre-industrial era. At the 15th Conference of Parties to the U.N. Framework Convention on Climate Change, held in Copenhagen in December, virtually all countries agreed that the warming must not surpass two degrees.
The report's conclusion: "For the Amazon as a whole, the remaining tropical forest will shrink to about three-quarters of its original area by 2025 and further to about only one-third of its original extension by 2075 as a result of these combined impacts of climate change, deforestation, and fire."
"The good news is that deforested areas can be reforested and provide a safety margin," said Lovejoy, maintaining some optimism.
It is estimated that a single hectare of Amazon rainforest contains about 900 tonnes of living plants, including more than 750 types of trees and 1,500 other plants, the report notes.
A single pond in Brazil can sustain a greater variety of fish than is found in all of Europe's rivers, and more than 2,000 species of fish have been identified in the Amazon Basin - more species than in the entire Atlantic Ocean.
The Andes mountain range and the Amazon jungle are home to more than half of the world's species of flora and fauna. For example, one in five of all birds in the world can be found there.
Sadly, before the end of this century many, and perhaps most, of those species will become extinct. After millions of years of existence many plants, insects, birds, animals will never be seen again on the Earth. Habitat loss and climate change will be the biggest reasons for their extinction.
The Intergovernmental Panel on Climate Change conservatively estimates that 30 percent of all species will be extinct by the end of this century, if global warming is not kept below two degrees.
Other experts, such as eminent Harvard entomologist E.O. Wilson, told participants at the UNESCO conference that extinctions could go as high as 50 percent.
"Our purpose this year is to focus the world's attention on the need to stop the destruction of biodiversity, the destruction of nature," Ahmed Djoghlaf, executive secretary of the Convention on Biological Diversity, said in the opening address of the conference in Paris.
The countries party to the Convention agreed in 1990 to slow the rate of biodiversity loss by 2010. "We will not meet that goal," Djoghlaf told Tierramérica.
However, with the launch of the International Year of Biodiversity, and the many events, celebrations and conferences to be held around the world, Djoghlaf hopes biodiversity, which is another term for nature, will garner interest and support from the public and policy makers.
With the theme "Biodiversity is life. Biodiversity is our life," organisers are launching a largely educational effort to explain that plants, animals, insects, birds, and bacteria make up the world's ecosystems, which provide humanity with food, fibre and clean water and air.
According to the Millennium Ecosystem Assessment, "60 percent of the world's ecosystems are degraded and failing. We have an obligation to change our ways. This is not a luxury," Djoghlaf said.
In October, the 193 countries that have signed the Convention will set new biodiversity reduction targets at a conference in Nagoya, Japan.
The failure to achieve the 2010 targets for protecting biodiversity resulted from countries' inability to define how they would reach them, Djoghlaf said.
He is confident that, having learned from these mistakes, countries will set specific national goals to curb species loss, with comprehensive plans on how to achieve them. That will then feed into a global target for 2020.
"We will have studies, reports and scientific indicators to guide us, but in the end it is up to policy makers to set targets and policies that will make it happen," said the biodiversity chief.
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