Rainforest Destruction and Climate Change
Spread over Africa, South America and Australasia, rainforests are the richest repositories of life forms on planet earth and its green lungs. One of our oldest ecosystems, rainforests are estimated to harbour 66% of all the species on earth! Today however many of the estimated 30-40 million species inhabiting these ecosystems are being lost, even before they can be catalogued, at a rate estimated at an astounding 50,000 species per year.
Not only are rainforests a vast repository of potential medicines they also play a vital role in producing oxygen and in maintaining global climatic patterns. The Amazon rainforests alone for example are responsible for 28% of the global oxygen turnover.
The role of green house gases like methane and carbon di oxide in global warming and climate change is well documented. Automobiles, ocean liners and aircrafts have been roundly criticized for belching these gases that threaten to bring doomsday to the earth’s doorstep. What is little understood and appreciated is the fact that rainforest destruction releases more than 1.5 billion tones of green house gases (IPCC estimates), a fifth of the total global emissions and more than all the other sources mentioned above put together (Houghton, 2003; BBC report). Destruction of an acre of rainforest releases a thousand tons or more of carbon dioxide (http://dsc.discovery.com/news/2009/06/16/australia-forest-carbon.html). The importance of conserving rainforests thus becomes obvious. Detractors have long hidden behind Odum’s view propounded in the 60’s that old rainforests do not help in trapping carbon dioxide. However a 2008 study has shown that these old forests continue to trap close to a billion tons of carbon dioxide every year. (Luyssaert et al., “Old-growth forests as global carbon sink,” Nature, 2008).
Rainforests have been at the receiving end of human greed and short sighted harvesting. Rampant rainforest destruction has shrunk rainforests to 50% of their earlier size, limiting them to a mere 6% of the earth’s surface. Estimates of the extent of rainforests lost vary from 17 million acres (United Nations estimate) to 50 million acres every year. The WWF puts destruction rates at 25 to 50 acres every minute. To put in perspective, an area of tropical forest large enough to cover North Carolina is deforested each year. Today rainforests are being lost in Brazil, Peru, Colombia, Indonesia, Malaysia, Zaire, Guinea and many other countries. Some projections suggest that the remaining rainforests could be lost within the next 4 decades.
Aspirations of economic growth in third world countries and lifestyle choices in the developed world are the twin driving force behind deforestation in poorer Latin American, Asian and African countries. Livestock grazing to meet the increasing demand for beef is alone responsible for a large part of deforestation. Close to 55 square feet of rainforests are cleared for every pound of beef produced releasing 500 pounds of carbon di oxide in the process (The burger that ate a rain forest – London Times, Feb 26, 1989)! Forest land converted to pasture also contributes to global warming by increased emissions of methane by cattle.
In Brazil alone 24,000 square kilometres of rainforests are cleared every year (Santilli et al., Climatic Change; 2005). Besides pasture, rainforests have been cleared for timber – with concessions sold as cheap as $ 2 per acre, cropland, bio fuel cultivation, to feed iron mills with charcoal and paper factories with wood pulp. A single multinational pulp manufacturing project in Brazil consumes close to 2000 tons of pristine rainforest every day! International debt repayment obligations have also been instrumental in encouraging many nations to hawk their forest resources for hard cash in place of higher returns they could have realized in the longer term by sustainable forest management practices.