For three weeks, swaths of the Amazon rainforest in Brazil have been engulfed in flames—2.5 million acres to be exact. Another 1.8 million acres are burning in neighboring Bolivia, and thousands of fires are raging in the forests of Angola and the Democratic Republic of Congo, in Central Africa. This has frightening implications for the Earth’s rapidly heating climate, but so does deforestation much closer to home.
On Tuesday, The Washington Post reported that President Donald Trump intends to exempt Alaska’s Tongass National Forest from the Roadless Area Conservation Rule, which has long protected certain U.S. forests from development. This would open up 9.5 million acres of undisturbed temperate rainforest in Alaska to mining, logging, and energy projects. Trump is also considering exempting 90 percent of national forests in Utah from the rule, which would open about four million more untouched acres to potential deforestation.
Trump has long attempted to decimate America’s forest for profit under the guise of “forest management.” Last December, Trump issued an executive order expanding the logging industry’s presence on public lands and arguing that increased timber harvesting would help reduce wildfire risk. Needless to say, the solution to worsening forest fires is not to get rid of the forest. Because trees absorb carbon dioxide from the atmosphere, forests are our biggest natural defense system against global warming. So if we want to prevent wildfires from becoming more deadly—among the many other effects of climate change—the world needs far more trees.
In other words, it’s not enough to simply put out the fires and stop deforestation. The planet must be aggressively reforested.
The evidence couldn’t be clearer on this point. The latest report from the United Nation’s Intergovernmental Panel on Climate Change (IPCC)—a group made up of scientists from 195 countries—says that keeping the Earth from warming beyond 1.5 degrees Celsius will require not only reducing emissions, but removing carbon that is already in the atmosphere. The most surefire way to do that, according to the IPCC, is through reforestation and ecosystem restoration. “It’s the only technology that’s currently available to remove carbon dioxide from the atmosphere at scale,” ecologist Will Turner recently told Mashable. (Though carbon-removal technologies have been experimented with, none are yet reliable or deployable on a massive scale.)
How much carbon needs to be removed? “The low-end IPCC estimate requires pulling 100 gigatons of carbon dioxide removal by 2100, roughly double the amount that humanity produces in a year today,” Vox reported last year. “The high-end estimate is 1,000 gigatons, effectively forcing humanity to undo 20 years of global greenhouse gas emissions.” Those goals can be met, at least in part, through reforestation. According to Vox, a study published last month in the journal Science found that “letting saplings regrow on land where forests have been cleared would increase global forested area by one-third and remove 205 billion metric tons of carbon from the atmosphere.”
The Earth, as a whole, has been losing its forests at a steady rate over the last three decades—from 41.2 million square kilometers in 1990 to 39.9 million square kilometers in 2016, according to the World Bank. That’s a net loss of forests equivalent to the size of Peru, or approximately twice the size of Texas. That number would be a lot higher, though, if it weren’t for other countries’ efforts to plant trees. China and India, notably, have made concerted efforts to increase their amount of forested land.
The increase in tree cover in those countries, however, “does not offset the damage from loss of natural vegetation in tropical regions, such as Brazil and Indonesia,” according to NASA. That’s partly because newer trees don’t provide nearly as big a climate benefit as older trees; according to one study published in 2017 and reported on by the Canadian Broadcasting Corporation, “Almost 70 percent of all the carbon stored in trees is accumulated in the last half of their lives.”
There are several caveats to reforestation as a climate solution. Not just any trees will do; some consume more water than others. And it’s not as though agricultural land can simply be replaced with forests, thereby disrupting the food supply and putting farmers out of work. “It’s got to be like tending a garden,” World Resources Institute Senior Fellow Frances Seymour told Mashable. Trees also take a really long time to grow, and mature forests absorb far more carbon than young ones. So reforestation isn’t a silver bullet solution to tackling climate change; it has to be paired with aggressive emissions reductions—the kind that can only come from a worldwide phase-out of fossil fuels.
If reforestation is going to absorb meaningful amounts of carbon from the atmosphere, it has to begin soon: As the climate warms, land that’s currently suitable for reforestation will increasingly become too hot for regrowth. But as time runs out, critical countries are trending in the wrong direction on this issue. Earlier this week, the Group of Seven nations pledged $22 million in help combat the fires in the Amazon. But Trump did not sign on to the aid package, and it’s not clear that Brazilian President Jair Bolsonaro, who has accused European leaders of neocolonialism amid the Amazon crisis, will accept it. “The fire that burns the strongest is that of our own sovereignty over the Amazon,” he wrote on Twitter. Days later, Trump tweeted that Bolsonaro has the “full and complete support of the USA!”