The selective logging and burning of trees carried out to clear land for farming in the Amazon rainforest releases 54 million tons of carbon into the atmosphere every year, according to a new study.
While rainforests are invaluable because of their biodiversity and importance to global ecosystems, they also provide an essential service, as trees store significant amounts of carbon. When released, this carbon can be a big contributor to climate change.
Such concerns have prompted worries over industrial scale deforestation in the Amazon – also known as “the lungs of the Earth”. Logging has slightly increased in recent years after years of decline, but most operations have been carried out illegally as efforts to protect the forest have scaled up.
But the new paper, authored by researchers from the UK and Brazil and published in the journal Global Change Biology, highlights an overlooked threat to the precious environment and the global carbon cycle.
“The impacts of timber extraction, burning and fragmentation have received little notice because all the efforts have been focused on preventing further deforestation,” explained Erika Berenguer of Lancaster University, lead author of the study.
“However, our study has shown that this other type of degradation is having a severe impact on the forest, with enormous quantities of previously stored carbon being lost into the atmosphere.”
In total, this destruction causes 40% of all emissions caused by deforestation in the Amazon, the researches say.
That is equivalent to the emissions generated by the electricity consumption of 7.5 million homes, or the burning of 125 million barrels of oil, according to the US Environmental Protection Agency’s online calculator.
However, this selective removal of trees is far more difficult to spot using satellite imagery than typical deforestation, where larger swathes of forest are destroyed.
Using painstaking, detailed satellite analysis alongside work in the field, the researchers put together a picture of the toll that has been inflicted on the forest over the last 20 years.
Testing samples, they found that areas of forest that had been disturbed by selective logging or burning contained 18% to 57% less carbon than healthier, intact areas of forest.
A separate study published last month concluded that global carbon emissions would fall by a fifth if deforestation in the tropics ceased.
Another recent analysis suggested that all the carbon stored in the world’s forests could be valued at around £2.77 trillion.
Photo: Ivan Mlinaric via Flickr