Deforestation is the large-scale clearing of forests, usually to make way for farmland, livestock grazing, logging, or urban development. It reshapes the environment at every level, from local soil and rainfall to the global climate. The tropics lost a record 6.7 million hectares of primary rainforest in 2024 alone, an area nearly the size of Panama, and the consequences ripple outward in ways that affect everyone.
Why Forests Are Being Cleared
Commercial agriculture, including cattle ranching, is the dominant force behind deforestation. A 2025 global meta-analysis found that commercial agriculture and livestock account for 83% of deforestation worldwide. Wood extraction drives about 52% of cases, and subsistence farming by small-scale households contributes to roughly 50%. These categories overlap because a single area of forest can be logged first, then converted to farmland or pasture.
The geography of forest loss is concentrated in the tropics. Brazil holds more tropical primary forest than any other country and accounted for 42% of all primary rainforest loss in 2024. Bolivia surged to second place that year, overtaking the Democratic Republic of the Congo despite having less than half its forest area. Mexico and Nicaragua also entered the top ten for the first time, driven partly by wildfire.
How Deforestation Drives Climate Change
Trees absorb carbon dioxide as they grow, locking carbon into their trunks, roots, and soil. When forests are burned or cleared, that stored carbon is released back into the atmosphere. Since 1850, roughly 30% of all human-caused carbon dioxide emissions have come from deforestation, making it one of the largest contributors to climate change outside of fossil fuels.
Standing forests also act as an ongoing carbon sink, continuously pulling carbon dioxide out of the air and slowing the rate at which it accumulates. Losing that sink is a double hit: emissions go up from the clearing itself, and the planet loses some of its capacity to absorb what’s already there.
Old-growth forests store far more carbon than younger, regrowing ones. In the Argentine Dry Chaco, researchers measured about 30 metric tons of carbon per hectare in primary forest compared to just 8 metric tons per hectare in secondary forest that had regrown after disturbance. Shrubby grassland that replaced forest held barely 1.4 metric tons. This means replanting trees helps, but it takes decades or centuries for a new forest to approach the carbon storage of the one it replaced.
Disrupted Rainfall and Water Cycles
Forests don’t just respond to rain. They help create it. Trees pull water from the soil and release it into the atmosphere through their leaves, a process that generates moisture that falls again as precipitation downwind. In the Amazon basin, this moisture recycling contributes up to 41% of the region’s total rainfall. In the Congo basin, the figure reaches 50%.
When small patches of forest are removed, the exposed land heats up faster than surrounding canopy, and the temperature contrast can actually trigger localized rain. But at larger scales, the opposite happens. Research published in Nature found that once cleared areas exceed about 50 kilometers across, rainfall drops measurably. The strongest declines appeared at the 200-kilometer scale, where each additional percentage point of forest loss reduced precipitation by about 0.25 millimeters per month. Climate models project that large-scale Amazon deforestation could cut the region’s annual rainfall by roughly 8% by 2050.
Less rainfall feeds a dangerous cycle. Drier conditions stress surviving trees, making them more vulnerable to fire, which destroys more forest and dries the landscape further. Scientists have warned that the Amazon could eventually cross a tipping point where large sections shift permanently from rainforest to savanna.
Soil Erosion and Land Degradation
Forest canopy and root systems hold soil in place. Leaves break the impact of raindrops, and roots bind the earth together. Remove the trees, and topsoil washes away at dramatically higher rates. A study in western Iran compared forested hillsides to nearby slopes that had been cleared and converted to vineyards. The deforested slopes lost soil roughly five times faster, around 26 to 33 metric tons per hectare per year compared to 5 to 6 metric tons under intact forest.
Topsoil is where most nutrients concentrate. Losing it degrades the land’s ability to support crops, which can push farmers to clear even more forest, creating another self-reinforcing cycle. Eroded sediment also flows into rivers and streams, clouding water, smothering riverbeds, and reducing water quality for communities downstream.
Biodiversity and Habitat Loss
Tropical forests cover less than 10% of Earth’s land surface but harbor more than half of all terrestrial species. When forest is cleared, animals and plants lose the habitat they depend on for food, shelter, and reproduction. Species with small ranges or highly specialized diets are especially vulnerable because they can’t simply relocate.
Fragmentation compounds the problem. Even when some forest remains, breaking it into isolated patches separates populations, limits genetic diversity, and makes species more susceptible to disease and local extinction. Edge effects along the boundary of cleared land change light, temperature, and humidity deep into the remaining fragment, degrading habitat quality well beyond the clearing itself.
Global Commitments and the Reality Gap
At the COP26 climate summit in Glasgow, over 130 world leaders representing more than 90% of the world’s forests pledged to halt and reverse forest loss by 2030. Twelve countries collectively promised $12 billion in forest-related climate finance between 2021 and 2025. Yet the record-breaking tropical forest loss in 2024, driven by agricultural expansion and fire, underscores how wide the gap remains between pledges and outcomes.
Reducing deforestation requires tackling the economic incentives that drive it. As long as cleared land is more profitable than standing forest, commitments alone won’t reverse the trend. Efforts that show some promise include paying landowners for the ecological services their forests provide, tightening supply-chain regulations so that commodities like beef, soy, and palm oil can’t be sold if they’re linked to illegal clearing, and restoring degraded land so that new agriculture doesn’t need to push into intact forest. The scale of forest loss in 2024 makes clear that these approaches need to accelerate dramatically if the 2030 target is going to mean anything.