Are Tropical Forests Still Capturing Carbon?

As well as being incredible epicentres of biodiversity, tropical forests throughout the Americas, Africa and Asia have traditionally been viewed as having two major benefits on the human race – their emission of oxygen and their absorption of carbon dioxide (CO2).

However, a new study from scientists at the Woods Hole Research Centre (WHRC) in Massachusetts, USA has revealed that the world’s tropical forests are now releasing more carbon than they trap, resulting in them becoming sources of the substance, rather than sinks. It’s thought that the reversal of roles is largely down to human deforestation, disturbance and degradation.

New approach yields alarming results

The new approach to measuring carbon loss throughout the tropics incorporated satellite images, field measurements and laser remote sensory technology from 2003 to 2014. By adopting this innovative method, a team of researchers led by Alessandro Baccini uncovered the disturbing truth about the forests in question.

The team found that the amount of carbon emitted by the forests exceeded the amount absorbed for the first time. Previous studies haven’t arrived at the same conclusion because it has traditionally been very difficult to assess the size of the impact that deforestation has had on the region’s ability to retain its stores of carbon.

“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,” explained Wayne Walker, one of the co-authors on the report. “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 wake-up call to the world

With the ratification of the Paris Agreement last year, the world’s leaders appeared to unanimously agree that the time for change is now. This latest study will add more fuel to the fire, if any was needed.

“These findings provide the world with a wake-up call on forests. If we're to keep global temperatures from rising to dangerous levels, we need to drastically reduce emissions and greatly increase forests' ability to absorb and store carbon,” warned Baccini. “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.”

It’s clear, then, that action must be taken swiftly and definitively to repopulate forested areas, halt deforestation efforts and reduce the harmful impact of human life on these important biospheres. But with people on social media apparently more concerned about the antics of Beyoncé than they are about deforestation, enacting such change may well be easier said than done.