A Race to Restoration in the Amazon

Stretched across eight countries, the world’s most important ecosystem houses 10% of all known wildlife species and 20% of the planet’s freshwater supply.

But somehow this wide-open space is also a tight vault, sealing away one of the largest threats to the fight against climate change.

More than 150 billion metric tons of carbon is stored within the Amazon Rainforest. The massive carbon sink is critical for global health. But if the forest were to lose its grip on the land and the lock on its carbon stores were to break, the equivalent of 15 to 20 years of global fossil fuel emissions would be sent into the atmosphere. The impact would ripple out across the world, warming the entire planet by at least a quarter-of-a-degree Celsius (nearly 9 degrees Fahrenheit).

All from the loss of a single forest.

“All of the tropics are important, but the Amazon is particularly so,” said Dr. Elena Shevliakova, a senior climate modeler at Princeton University.

For that reason, the Arbor Day Foundation has identified the Amazon River Basin as one of five priority regions for its work related to reforestation. Alongside local partners, the global tree planting nonprofit aims to restore this hub for biodiversity, freshwater, and carbon storage.

Unfortunately, human-caused deforestation and the effects of climate change have put this invaluable region at risk.

Researchers believe 17% of the Amazon Rainforest’s original tree cover has already been lost. Dr. Shevliakova and other scientists have developed models that project continued effects of climate change and deforestation. They found the starting line for an accelerated path to total forest loss is closer than many people realize. Scientists estimate once 40% of trees in the Amazon are lost the land would start to naturally transition to a savanna grassland, a degraded ecosystem.

The forest would cease to be a forest, and it would happen fast. 

Some scientists believe the ‘tipping point,’ could be reached in some parts of the Amazon as soon as 2050. And as more trees are lost, more stored carbon is released into the atmosphere. Losing the entire forest would impact the entire planet. Shevliakova said it’d be particularly dire in the local region. Temperatures would likely rise several full degrees and rainfall would be reduced by up to 30%.

“That's one of the major importances of the forest, besides being a carbon sink and beside being this biodiversity reservoir. It's also a place which anchors local climate. It keeps the terrain in place,” she said. “If you cut out the forest, you’re going to make that local climate miserable.”

That’s because the climate of the Amazon is largely controlled by the Amazon itself.

The unique tropical climate of the Amazon Rainforest heightens the forest’s carbon storage efficiency.  

“Because the Amazon has such a special climate and it’s a big area capturing carbon year-round, you look at the carbon density [of each tree] and the number is much higher in the Amazon than what it would be in another forest,” Shevliakova said.

The Amazon Rainforest is able to thrive because of the abundance of rain in the region, which is created by the abundance of trees. Of the 9 feet of rain that falls each year in the region, the forest generates at least half of it. 

“When you have trees growing, they’re sending water to the atmosphere and then that water eventually becomes rain and provides trees the conditions they need to continue to grow,” Shevliakova said. 

But there’s disturbances at play. 

“People are using more fossil fuels, greenhouse gases go up and it changes the atmosphere. Precipitation actually starts to go down,” she said. “Once the rain is gone, it’s not going to be a forest.”

So deforestation is leaving fewer trees in a climate change-impacted atmosphere, which creates less rain and makes the forest hotter and drier. 

“The model is basically saying that if you don’t do anything about climate change, the place starts to go up in smoke,” Shevliakova said. “The forest becomes drier, places start to burn, and after they burn, the trees cannot reestablish because grass is preventing seedlings from growing. And because it’s hot, the fire keeps coming back.”

Scientists have already begun to observe a pattern of increasing drought and wildfire in the Amazon. Since 2001, fires have damaged the habitat of more than two-thirds of the animal species living in the forest. Wildfires are exacerbating the tree loss in the forest, again pushing the ecosystem closer to the edge of the 40% tipping point. 

Every time, it all comes back to trees. The fate of the forest hangs in the balance, but the window of opportunity has not yet closed. Reforestation efforts can preserve the landscape and grow more resilience.