Dozens of countries have extraordinary tropical forests, but three stand out: Brazil, Indonesia, and the Democratic Republic of Congo. These countries not only have the largest areas of tropical forest within their borders, they also have the highest rates of deforestation.
We traveled to protected areas deep inside these countries to learn the superpowers of three tree species that play an unusually important part in staving off environmental disaster, not just locally, but globally. These trees play many ecological roles, but most impressive is how they produce rainfall, remove carbon dioxide from the atmosphere, and support hundreds of other species.
If these ecosystems collapse, the climate effects are likely to be irreversible. And so what happens to these forests truly affects all life on Earth.
This is the story of three trees at the center of our climate crisis that provide big benefits to you, me, and the world. Meet the trees, get to know their superpowers, and learn how scientists are trying to protect them.
This project was supported by the Pulitzer Center.
Meet the Amazon’s Rainmaker
This is the Brazil nut tree, Bertholletia excelsa, an icon of the Amazon rainforest. It’s one of the taller species in South America, reaching the height of a 14-story building.
The Brazil nut tree makes, well, tasty nuts. But its real superpower is channeling an extraordinary amount of water from the soil to the sky, making the rainforest rain.
A single tree can pump more than 260 gallons (or 3.5 full bathtubs) of water per day up its trunk and through its leaves into the air.
Brazil nut’s superpower is making it rain
Here’s how it works:
1 Water in the soil enters through the roots.
2 The water moves up the trunk.
3 The leaves release water and particles that help it condense into rain clouds.
4 The rain falls out of the sky and back onto the forest.
The Brazil nut tree helps the Amazon rainforest — which extends into eight countries — produce up to half of its own rainfall. (The arrow points to the Uatumã Sustainable Development Reserve, in the heart of the forest, where we visited the Brazil nut tree.)
This NASA weather simulation shows how rain clouds are constantly bubbling up over the Amazon and moving across the continent. At times, there is more water in the air than in the 4,000-mile river below that gives the region its name.
The 21 million people of the São Paulo metro area, roughly 1,500 miles from the Amazon, rely on this rainfall for drinking water. Farmers throughout Brazil need it for irrigation.
The Amazon also acts like a massive air conditioner, keeping temperatures down. Climate studies show that when the Amazon is leveled, local temperatures jump by at least 2.5 degrees Fahrenheit on average.
Here, at the Amazon Tall Tower Observatory, or ATTO, scientists strap on harnesses to study the rainforest way above the treetops.
ATTO rises 1,066 feet above the forest floor, about the height of New York’s Chrysler Building. The observatory includes three towers; the largest is the tallest structure in South America.
Here on the tallest tower, scientists measure wind speed and moisture levels. They also track the chemicals fluxing between the trees and the sky that turn the moisture into rain clouds. It can be precarious work.
Scientists like Delano Campos use the towers like a wide-angle camera lens to get a better read on the rainforest than what can be sensed from the ground.
From the towers, they can detect signs of deforestation like this in Rondônia, a nearby province. Researchers fear if soy farmers, cattle ranchers, and miners keep destroying the forest, there may be more severe and frequent droughts.
This green box represents the entire Amazon rainforest. The orange is the 17 percent that’s already been destroyed. With current rates of deforestation, this could hit 25 percent in 15 to 30 years, at which point the Amazon may not make enough rain to sustain itself. The world’s biggest rainforest would then begin an irreversible collapse, eventually turning into dry savanna.
This looming tipping point is why the surge in forest clear-cutting this year is so worrying. Activists and scientists blame President Jair Bolsonaro, who has shown a complete disregard for conservation since he took office in 2019.
As more trees are cut down, there will be more frequent droughts, endangering food and water supplies, and livelihoods for millions of people.
That’s why giants like Brazil nut trees are so vitally important. Their ability to produce rain that feeds and cools the rest of the Amazon — and the region — is a true superpower.
By studying these trees, scientists can help predict the irreversible consequences of deforestation. Their work shows those in power the extraordinarily grave risks — to Brazil, South America, and the planet as a whole — of destroying the world’s largest tropical forest.
Meet Indonesia’s Carbon Guardian
This is the stilt mangrove, Rhizophora, a species that dominates parts of Indonesia’s coasts. Every day, the tide rolls in and covers its roots in briny water.
At low tide, its roots emerge — tall and spindly.
Stilt mangroves do a lot for coastal communities, protecting them from typhoons and tsunamis. Fish depend on them, too: Baby snapper and grouper use them as a nursery, and shrimp use them as a breeding ground.
But this tree’s most impressive superpower happens underground, where its roots end and the mud begins.
Our current climate crisis is a result of humans putting too much carbon dioxide in the atmosphere. Luckily, trees (and other natural systems) can remove and store some of that carbon. The stilt mangrove is unusually good at this task.
Stilt mangrove’s superpower is keeping carbon underground
Here’s how it works:
1 The tree absorbs carbon from the atmosphere and uses it to grow its trunk, leaves, and stems.
2 The carbon-rich plant material eventually falls off the tree and ends up in the soil.
3 In the wet soil under the roots, the carbon can’t return to the atmosphere because it’s sealed off from the air. It can remain there for millennia.
These orange lines don’t look like much, but Indonesia has 23 percent of all the mangrove areas on Earth — covering 7.1 million acres, the size of Belgium. (The arrow points to Tanjung Batu, East Kalimantan, where we visited the stilt mangrove.)
Rainforests get a lot of credit for being carbon sinks. But scientists have discovered that an acre of mangroves can store five to 10 times as much carbon as an acre of rainforest.
The stilt mangrove isn’t just storing carbon above ground, but also in the soil, up to 10 feet down. There, as “blue carbon,” it’s an underground vault, secure for millennia, as long as it’s sealed off from the air.
This ability to both remove carbon and keep huge stores of it protected is a tremendous asset in the climate crisis. It’s why preserving and restoring mangroves is being hailed as a promising “negative emissions technology.”
Here’s a palm oil refinery in East Kalimantan on the Indonesian island of Borneo. Over the past three decades, Indonesia has lost 40 percent of its mangroves to palm oil plantations, shrimp farms exporting to the US and China, and pollution.
Indonesian scientists like Novi Susetyo Adi are racing to measure the carbon in mangroves to show the government this ecosystem’s enormous potential for fighting climate change.
He and a team of scientists from the Ministry of Fisheries and Marine Affairs, with partners from Japan, are in East Kalimantan to take samples from the trees and soil. But because Indonesia’s mangroves are spread over thousands of islands, research and protection are an immense challenge.
When mangroves are cut down, the soil beneath the trees is exposed to air and starts producing greenhouse gases. This ecosystem is terrific at storing carbon, but there’s a dangerous flipside when it’s disturbed.
Since Indonesia’s mangroves hold the largest blue carbon stocks in the world, many scientists are calling for stricter laws against deforestation here. Mangrove destruction will only accelerate the climate crisis and doom the hundreds of millions of people in Indonesia’s coastal communities to worsening sea-level rise and dying fishing areas.
Meet Congo’s Forest Caretaker
With its leopard-print bark and towering pencil-straight trunk, the Afrormosia or African teak tree (Pericopsis elata) cuts a stunning figure in the Congo Basin rainforest. This is the second-largest rainforest on Earth, and like the Amazon and Indonesia’s coasts, it plays a crucial role in regulating rainfall and storing carbon. But this rainforest is the least studied and most overlooked.
The Congo Basin stretches into six countries in Central and West Africa. It’s a place of staggering, exuberant biodiversity. Here, a mother and baby Grauer’s gorilla, a critically endangered species, climb through the forest in the Kahuzi-Biega National Park in the Democratic Republic of Congo.
A wide, tall tree with dense wood, Afrormosia is an important carbon sink in the Congo Basin rainforest. But its superpower is its resilience and ability to support other species — and the entire ecosystem — around it.
Afrormosia’s superpower is being a forest caretaker
Here’s how it works:
1 When food is scarce, birds and monkeys can feast on Afrormosia’s unripe seed pods.
2 Its leafy canopy provides shade for plant and animal species on the ground.
3 Its flame-resistant bark can weather natural and man-made fires, allowing the tree to help other species recover.
The dark green area is where the only major population of Afrormosia remains. The shaded area is where it was found as of 1950. Since then, the tree has all but gone extinct in Ivory Coast, Nigeria, and Cameroon. (The arrow points to the Yangambi Biosphere Reserve, where we visited Afrormosia.)
A key reason Afrormosia survives in Congo is the country is virtually landlocked and has poor infrastructure. Violence has also slowed the country’s development. And even here, the tree is not safe.
Demand for Afrormosia’s yellowish-brown wood continues to be high, in Africa and beyond. Yacht builders and floor makers prize its consistent texture and resistance to decay.
Many people in this developing region rely on selling Afrormosia’s high-value timber for their livelihood. Managing the species — so that the forest remains resilient and people can continue to use the wood — is the key to its survival.
A team of Central and West African scientists at Yangambi Research Station on the Congo River is trying to find new ways to help the tree thrive. Currently, Afrormosia takes several decades to reach maturity, and it’s not easy to make it grow faster.
Afrormosia needs a lot of light to grow. It waits patiently until a tall tree falls or is logged, creating an opening in the canopy above. Then it races upward.
Scientists still have much to learn about this species. Here, Chadrack Kafuti measures a tree’s growth rate and captures the data on his laptop.
Back in the lab, Kafuti uses a microscope to look at a tree sample. He’s studying how Afrormosia’s growth rate responds to light, drought, logging, and climate change in different forests.
This room full of samples could help the Yangambi researchers figure out the ideal conditions for Afrormosia to thrive. They’re worried that if too many trees are logged, it will threaten the resilience of the entire forest ecosystem.
At an Afrormosia nursery, Hulda Hatakiwe nurtures hundreds of seedlings and saplings. One day, she hopes farmers will cultivate the tree, too.
But it’s a race against time as loggers — both legal and illegal — reach deeper into the forest to satisfy the insatiable market for this wood in the US, Europe, and China.
There is an alternative: purchasing only sustainably harvested Afrormosia under the rules of the Convention on International Trade of Endangered Species, or CITES. The international community can also support Congo’s government in punishing illegal loggers.
If Afrormosia goes extinct, it could threaten the forest’s resilience and stability, increasing greenhouse gas emissions, and unleashing more chaotic weather on Africa and the rest of the world. It’s in everyone’s interest to protect these trees.
Brazil nut, stilt mangrove, and Afrormosia are just three species in three wildly diverse and important ecosystems. But they all make remarkable contributions to the communities around them — and to those of us continents away. As new science has revealed, we are much more dependent on these parts of the world than we might think.
When it comes to the crises of global warming, extreme weather, and biodiversity loss, it really does matter if the Amazon reaches the tipping point, if a stretch of Bornean mangrove gets razed to build a shrimp farm, or if a tall yellow giant in Congo goes extinct. It’s not just losing a pretty tree 12,000 miles away — it’s cascading ecosystem collapse with long-range effects. We may not feel those effects yet, but we will feel them in our lifetimes. ️
Want to help? Read Vox’s piece on six high-impact organizations working to fight climate change.
This project was supported by the Pulitzer Center.