Deforestation and Climate Change: How Losing Forests Warms the Planet
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Forests cover roughly a third of the world's land. They are home to most of the planet's land-dwelling species, they supply water and livelihoods to billions of people, and they hold an enormous amount of carbon in their trees and soils. When forests are cleared, much of that carbon ends up in the atmosphere. This explainer covers how deforestation and climate change are linked, what drives forest loss, and what is working to slow it.
Key points
- Deforestation means permanently converting forest to another land use, such as farmland or pasture.
- Clearing and burning forests releases carbon dioxide; land-use change is a significant source of human CO2 emissions.
- Most tropical deforestation is driven by agriculture, especially cattle ranching and crops such as soy and oil palm.
- The UN Food and Agriculture Organization reports that the rate of deforestation has slowed since the 1990s but remains high.
- Protecting existing forests is generally the fastest and most reliable forest-based climate action; restoring forests helps too, but takes decades.
What counts as deforestation?
Not every felled tree is deforestation. The term usually refers to a lasting change in land use, where forest is replaced by something else: fields, pasture, mines, roads or towns. Logging that is followed by regrowth is usually counted as forest degradation rather than deforestation, though heavy degradation can also release a lot of carbon and harm wildlife.
The UN Food and Agriculture Organization's Global Forest Resources Assessment is the main international source of forest statistics. In its 2020 assessment, FAO estimated that about 10 million hectares of forest were lost to deforestation each year between 2015 and 2020, down from roughly 16 million hectares per year in the 1990s. Some of that loss is offset by forests expanding elsewhere, so the net loss is smaller, but newly planted or regrowing forest is not equivalent to old, intact forest.
Satellite-based tools such as Global Forest Watch track tree cover loss in near real time. Because they measure all tree cover loss, including from fires and logging, their numbers are not directly comparable to FAO's deforestation figures.
Forests and the carbon cycle
Trees take carbon dioxide from the air as they grow and store the carbon in wood, leaves and roots. Forest soils, especially peat soils in places like Southeast Asia and the Congo Basin, store even more. Altogether, the world's forests hold a very large amount of carbon, and healthy forests absorb a substantial share of the CO2 that humans emit each year.
When a forest is cleared, three things happen:
- Stored carbon is released. Burning releases it quickly; decay releases it over years. Drained peatlands can keep emitting for decades.
- Future absorption is lost. The land no longer pulls carbon out of the air as the forest did.
- Local climate changes. Cleared land is often hotter and drier than forest.
The IPCC's Special Report on Climate Change and Land found that agriculture, forestry and other land use together accounted for a significant share of global greenhouse gas emissions, with deforestation a major contributor. For how those emissions trap heat, see What is the greenhouse effect?
From carbon sink to carbon source
Scientists are watching whether some forests could shift from absorbing more carbon than they release to releasing more than they absorb. Studies have suggested that parts of the southeastern Amazon, where clearing, fires and drought have been most intense, may already have become a net source in some years. Results vary by method and region, but the concern is that forests under heavy pressure cannot be relied on to keep soaking up our emissions.
What drives deforestation
The drivers vary by region, but agriculture dominates, especially in the tropics.
| Driver | Where it is prominent | Notes |
|---|---|---|
| Cattle ranching | Latin America, especially the Amazon | Often the largest single driver in the region; pasture frequently follows clearing. |
| Commodity crops | Brazil, Indonesia, Malaysia, parts of West Africa | Soy, oil palm, cocoa and others, often linked to global trade. |
| Small-scale farming | Central Africa, parts of Asia | Shifting cultivation and subsistence farming, often tied to poverty and population pressure. |
| Logging and mining | Many tropical and boreal regions | Roads built for logging or mining open forests to further clearing. |
| Infrastructure and settlements | Worldwide | Roads, dams and urban expansion. |
Underlying these direct causes are deeper factors: global demand for food and commodities, weak land rights, limited enforcement of laws, and economic incentives that make cleared land more valuable than standing forest.
Effects beyond carbon
Wildlife and biodiversity
Tropical forests are among the most species-rich places on Earth. Clearing destroys habitat directly and breaks remaining forest into fragments that are too small or isolated for many species. Habitat loss is widely considered one of the leading drivers of biodiversity decline worldwide.
Water and rainfall
Forests, especially large ones like the Amazon, recycle moisture. Trees draw water from the soil and release it into the air, which helps form clouds and rain further inland. Large-scale clearing can reduce regional rainfall, with knock-on effects for farming, hydropower and the forest itself.
Tipping points
Some scientists have raised concern that the Amazon could reach a tipping point beyond which large areas shift from rainforest to drier, savanna-like vegetation, driven by a combination of deforestation, warming and drought. Where such a threshold lies, and whether it would be crossed abruptly, remains uncertain and debated.
What helps
Evidence points to several approaches that reduce deforestation, especially when combined:
- Enforcement and monitoring. Brazil cut Amazon deforestation sharply in the 2000s and early 2010s through satellite monitoring, enforcement and protected areas, showing that policy can make a large difference; rates have since risen and fallen with changes in policy.
- Indigenous land rights. Studies have frequently found lower deforestation rates in territories managed by Indigenous peoples and local communities with secure land rights.
- Deforestation-free supply chains. Commitments and regulations that require commodities such as beef, soy, palm oil and cocoa to be traceable and not linked to recent clearing.
- Payments for keeping forests standing, including international programs that reward countries for reducing deforestation.
- Restoration of degraded land through natural regrowth and planting native species.
Can we just plant trees? Tree planting and natural regrowth can help, but young forests store far less carbon than old ones and take decades to mature. Planting the wrong trees in the wrong places, such as on natural grasslands, can harm ecosystems. Protecting existing forests avoids emissions now, while restoration builds carbon stores over time. Both matter, but neither replaces cutting fossil fuel emissions.
What you can do
As a consumer, you can look for credible certifications on wood, paper, palm oil, coffee and cocoa, eat less beef if that fits your life, and support organizations working on forest protection and Indigenous rights. For other practical steps, see What can one person do?
The bottom line
Deforestation releases stored carbon, removes a natural carbon sink, and harms wildlife and rainfall patterns. It is driven mainly by agriculture, and it has slowed globally but remains high. Experience shows that monitoring, enforcement, land rights and cleaner supply chains can cut forest loss substantially, making forest protection one of the most important nature-based climate actions available.