The Amazon Rainforest is known to emit a whopping 255 million metric tons of carbon a year. The reality is that this number could be much, much higher due to forest fires that South American governments don’t typically quantify, according to a study out in Nature Communications Tuesday.
This study involved a regional assessment of the Brazilian Amazon and the fires that ravaged the forest during drought years between 2003 and 2015. When people cut down trees, they usually burn them, too, explains Luiz Aragão , the lead author of the study who also runs the tropical ecosystems and environmental sciences group at Brazil’s National Institute for Space Research. These are the emissions governments typically quantify when calculating deforestation emissions in the Amazon.
Aragão and his team found, however, that the wildfires that spread away from man-made fire use during drought to, for example, burn crops or clean pasture land, can double the amount of carbon emissions during these dry spells.
While deforestation rates have been dropping in Brazil (though some are skeptical of this data), the number of wildfires is not. And carbon is still being released: a whole 454 million metric tons of CO2 on average a year. The numbers fluctuated from year, to year, with years like 2009 and 2011 seeing less carbon emissions, and other years like 2005 and 2007 seeing dramatically higher levels of carbon emissions. To compare, 454 million metric tons was close to Italy’s total annual carbon emissions in 2015.
“We are going to see forest fires becoming the dominant source of emissions in the Amazon in a drought climate scenario,” Aragão told Earther. “The only way we can reduce it is if we have policies looking at these fires.”
In short: Preventing deforestation isn’t really reducing emissions if officials are ignoring the emissions from wildfires during drought years. And though drought isn’t causing these fires, it is the factor that’s allowing them to leak into the forests, Aragão said.
Wildfires in the Amazon don’t work the way they do in, say, California. The rainforest is, well, wet. Under normal non-drought conditions, fires don’t spread so easily. When a drought strikes though, they do—and can end up burning old growth trees whose carbon might have been stored for decades or even centuries.
“What we have to do is really start reporting these emissions to know the magnitude and be able to develop policies that will mitigate this type of event,” Aragão said.
The study used satellite data and greenhouse gas inventories to arrive at its numbers, but it doesn’t take into account the fact that forests recover much more quickly following a fire than after deforestation, reports Carbon Brief. Still, Aragão wants to see countries like Brazil develop policies that reduce the amount of fire community members are using in the Amazon—but in a way that is equitable and fair to those who rely on fire to manage their land.
Many of those who call the forest home use fire to manage crops they rely on to eat, and fire is the most feasible way to prepare the soil for the next harvest. If any government expects people to stop burning their land, it will need to offer them some help, Aragão continued.
“We need to give them options to manage their lands without the use of fire—like machinery they don’t have at the moment,” Aragão said. “Governments will need to invest in these types of things to reduce the use of fire.”
That’s one part of it. So is improving the capacity to combat fires and protecting the forest so it can better withstand these fires. When loggers cut down trees and create fragmented sections of forest, the canopy opens and becomes more susceptible to these natural disasters.
Governments need to take action soon if they want to avoid a worst-possible outcome. Though the study didn’t look at this, Aragão said this situation is likely going to worsen if climate change models prove true, and the region grows drier. When the forest burns, trees not only emit carbon-filled smoke that’s exacerbating the speed of climate change destruction. These fires also spew pollutants into the air that threaten the health of nearby communities. This is bad news all around.
“There is a feedback loop where people use fire, but they also suffer the consequence of fire,” Aragão said. “These are the things that are coming out now, and people are becoming more aware, but we still need to link all these things in terms of policies to really minimize these negative impacts of fire on the carbon and also on the human health.”