Tropical forests have been so damaged by humans that they now pollute the planet more than they protect it.
The planet’s forests and oceans are vital ‘carbon sinks’ which prevent polluting gases reaching our atmosphere.
The massive Amazon forest alone sucks up 600 million tons of carbon emissions a year.
But scientists now say so many trees have been lost from tropical forests that they now produce more carbon than they absorb.
Tropical forests have been so damaged by humans that they now pollute the planet more than they protect it. Scientists now say so many trees have been lost from tropical forests that they now produce more carbon than they absorb
This is due to the massive logging industry, farmers felling trees for fuel, forest fires and disease.
A study involving Boston University worked out the carbon sent into the atmosphere by these trees after they are burned or die.
They found, subtracting the carbon they store, that tropical forest trees produce 425 teragrams of carbon a year. This is more than is pumped out by all the traffic in the US.
Lead author Dr Alessandro Baccini, from Woods Hole Research Centre in Boston, described the findings as a ‘wake-up call’.
He added: ‘Forests are the only carbon capture and storage ‘technology’ we have in our grasp that is safe, proven, inexpensive, immediately available at scale, and capable of providing beneficial ripple effects – from regulating rainfall patterns to providing livelihoods to indigenous communities.’
The team used 12 years of satellite imaging, laser technology and field measurements to calculate the loss of trees in the world’s forests.
Co-author Dr Wayne Walker, from Woods Hole Research Centre, said: ‘It can be a challenge to map the forests that have been completely lost.
However, it’s even more difficult to measure small and more subtle losses of forest.
Subtracting the carbon they store, tropical forest trees produce 425 teragrams of carbon a year. This is more than is pumped out by all the traffic in the US
‘In many cases throughout the tropics you have selective logging, or smallholder farmers removing individual trees for fuel wood. These losses can be relatively small in any one place, but added up across large areas they become considerable.’
A tree is approximately 50 per cent carbon, which is released back into the atmosphere when it is cut down. That can happen quickly, where the wood is burned or pulped, or more slowly if it is turned into furniture which later decomposes.
The paper, published in the journal Science, found the majority of lost trees, 60 per cent, were in Latin America, which contains the 550 million hectare Amazon forest.
Nearly 24 percent of the loss is attributable to Africa while the forests of Asia experienced the fewest losses, based on trees but not including the carbon in soil and other vegetation.