The Amazon basin spans South America and contains 40 percent of the world's remaining tropical forest. But every year more and more is being cut down - last year about twenty-five-and-a-half-thousand square kilometres of forest were felled.
This year, it seems, even more is going up in flames. As environmentalists call for action, the Brazilian government is attempting to curb the deforestation. But why is the Amazon rainforest so special? In this week's Big Question, Sue Branford asks: why does the Amazon matter?
It is the biggest forest in the world. The Amazon basin covers about half of South America, spreading into nine countries. The main River Amazon, which rises in the Andes mountains, flows six and a half thousand kilometres eastwards across Brazil. On reaching the Atlantic Ocean, it is at least 150 kilometres wide. More than a fifth of the water pouring into the oceans of the world comes from the Amazon.
So what is the scale of the deforestation? Most of the land being cleared is in the south and east of the Amazon basin. Over the past thirty years, it has been cleared - for timber or cattle, for smallholdings and for large soya bean farms. Soya beans are Brazil's leading export product.
Blairo Maggi, the governor of the State of Mato Grosso is nicknamed the "Rei da Soja" - the King of Soya. He is the world's largest soya farmer. What does he make of the charges that the Amazon is being devastated? "Less than 15% of Brazil's Amazon basin has been opened up for economic activities," he tells The Big Question. "Both Europe and the United States grew by taking advantage of their natural resources… and I think it is unacceptable interference, when they come and tell us what we should do. Brazil has its own environmental legislation, one of the most rigorous in the world, and yet we're treated as if we're bandits."
When the rains have fallen, the river rises by up to 14 metres. Biodiversity is a word often associated with the Amazon. The forest contains a fifth of all the known plants on earth. It is home to 2.5 million insects and 75,000 types of tree. There are 90,000 living plants in a single square kilometre.
"It's the most biologically diverse real estate on the planet," says William Laurance, from the Smithsonian Institution in the US, has been studying tropical forests for about 20 years. "One biologist found more ants in one tree in the central Amazon than occurred in the whole of Great Britain." The forest is also believed to contain thousands of plants and insects that have still not been discovered, let alone studied, by scientists.
Many pharmaceutical drugs derive from tropical rain forests. "Biochemists don't really create new compounds," says William Laurance, "they use the millions of years of evolutionary innovation that have occurred in tropical rain forests, in which plants have had to evolve incredible compounds to defend themselves from insects and other organisms that are trying to eat them."
What worries people like Laurance is that this pharmaceutical store cupboard is being destroyed. What about the effect on the global climate? It's almost a cliché to describe the Amazon forest as "the lungs of the world", with its image of trees discharging oxygen into the atmosphere. However, it is now believed that during the night, the Amazon forest uses up most of the oxygen it produces during the day.
So what will be the impact on the climate change if the Amazon continues to be cut down? The Brazilian Institute of Space Research (INPE) monitors the destruction of the Amazon forest using satellite imagery. INPE's Carlos Nobre tells The Big Question that burning to clear the forest is the main source of Brazil's greenhouse gas emissions:
"The rains in the Amazon are very important for the atmosphere, for the circulation, for the winds all over the world. So a change in the rainfall patterns in the Amazon might impact rainfall patterns in remote areas of the planet. We know that the potential for affecting distant regions exists."
This edition of The Big Question was first broadcast on 25th September 2004
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