Effects of Deforestation on the Environment

The effects of deforestation reach far beyond the cleared patch of land. When forests are cut, stored carbon escapes into the air and topsoil washes away. Rivers flood and then run low, dry land can turn desert-like, and wildlife loses its homes. Millions of people who live by forests also lose food and income.

This article is part of our guide on why forests are important. Here we look at what happens after forests disappear. The reasons forests are cleared are covered separately in deforestation: meaning and causes.

What is deforestation, in short?

The India State of Forest Report (ISFR) 2023 defines deforestation as the conversion of forest to another land use, whether people cause it or not. Its examples include farmland, pasture, reservoirs, mines and urban areas.

The problem is still large worldwide. According to FAO’s Global Forest Resources Assessment (FRA) 2025, about 489 million hectares of forest have been lost to deforestation since 1990. The yearly rate has fallen to 10.9 million hectares in 2015-2025. FAO still calls that rate too high.

What are the effects of deforestation on the environment?

The effects fall into five environmental groups, plus social and economic ones. The table gives a quick overview before each effect is explained.

How does deforestation affect climate and carbon?

Trees take in carbon dioxide for photosynthesis, the process by which green plants make food from sunlight, water and carbon dioxide. The carbon is then locked in their wood. National Geographic explains that burning trees sends this carbon back into the atmosphere as carbon dioxide. With fewer trees to absorb it, this greenhouse gas builds up and speeds up global warming.

Forests hold an enormous carbon store. FRA 2025 puts the world’s forest carbon stock at about 714 gigatonnes. Global stocks have grown since 2000, but FAO reports sharp declines in tropical forests. National Geographic notes that the greatest amount of deforestation today is in tropical rainforests.

India’s forests matter here too. As per ISFR 2023, they held 7,285.5 million tonnes of carbon, up 81.5 million tonnes on the previous assessment. The same report, quoting the IPCC (2019), names deforestation alongside fossil fuels and farming as a human activity raising greenhouse gas levels. Every hectare cleared shrinks this store.

Local climate changes as well. National Geographic notes that a cleared forest shifts from a closed, moist place to an open, dry one. The remaining plants then become more likely to catch fire. Our guide to forest fires: causes, effects and prevention explains that danger in detail.

How does deforestation cause soil erosion?

Soil erosion is the wearing away of the top layer of soil by water or wind. In a forest, roots grip the soil and a blanket of fallen leaves softens the impact of raindrops. Once trees go, nothing protects the ground.

National Geographic notes that tree loss leaves soil more prone to erosion. FAO’s State of the World’s Forests 2018 lists soil erosion and land degradation among the results of land-use change. The fertile topsoil is usually the first to go, so crops on cleared slopes soon give poor yields.

Washed-away soil does not simply vanish. It settles in streams, lakes and reservoirs as silt, making them shallower. India’s forest policy, as summarised in NCERT’s Class 11 geography book, also aims to check soil erosion. For practical methods, see ways to prevent soil erosion.

How does deforestation affect the water cycle and cause floods?

Forests act like a sponge. Rainwater soaks slowly into the leaf litter and soil, then recharges groundwater. Trees also release water vapour through their leaves, a process called transpiration, which returns moisture to the air.

Clearing breaks this cycle. Rain falls on bare, hard ground and rushes off the surface. Rivers swell quickly after storms, and floods become more likely. Later, with little water stored underground, springs and streams may run low or dry up.

FAO data show how much is at stake. In State of the World’s Forests 2018, FAO says three-quarters of the world’s accessible freshwater comes from forested watersheds (areas of land that drain into one river or lake). It adds that 40 per cent of the world’s 230 major watersheds have lost more than half of their original tree cover. In its October 2025 release on FRA 2025, FAO notes that forests can reduce the risks of floods, drought, landslides and soil erosion.

Water quality suffers too. FAO links water quality directly to forest management. Silty runoff from cleared land can also muddy rivers and drinking-water sources. For the full range of water benefits, read our article on forest ecosystem services.

Does deforestation lead to desertification?

Desertification is land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities. ISFR 2023 uses this UNCCD definition. It does not mean a sand desert suddenly appears. Instead, dry land slowly loses its soil, plant cover and ability to grow food.

Deforestation pushes dry areas in this direction. Without trees, soil dries out, erodes and loses its organic matter. Grasses and shrubs struggle to regrow, and wind carries away the loosened topsoil.

FAO lists desertification among the risks that forests help reduce. In India, NCERT’s Class 11 geography book records that the forest policy aims to check the extension of desert lands and reduce floods and droughts. Protecting tree cover is therefore part of protecting farmland in dry regions.

How does deforestation cause loss of biodiversity?

Biodiversity means the variety of living things in an area. Forests support a great deal of it. FAO’s State of the World’s Forests 2020 says forests are habitats for 80 per cent of known amphibians. They also shelter 75 per cent of bird species and 68 per cent of mammal species.

NCERT’s Class 12 Biology book (Reprint 2026-27) calls habitat loss and fragmentation the most important cause driving plants and animals to extinction. It notes that tropical rainforests once covered more than 14 per cent of Earth’s land surface but now cover no more than 6 per cent. NCERT describes the Amazon, called the “lungs of the planet”, as being cleared for soya beans and cattle pasture.

What is habitat fragmentation?

Fragmentation happens when a large forest is broken into small, separate patches by roads, farms or settlements. NCERT explains that mammals and birds needing large territories, and animals that migrate, are badly affected. Their populations then decline.

National Geographic adds that logging or burning tropical forests can drive many species into extinction. When one species disappears, animals and plants that depend on it are also at risk. Read loss of biodiversity: causes, effects and solutions for the wider picture.

What are the social and economic effects of deforestation?

Deforestation also hurts people, especially the poorest. FAO’s State of the World’s Forests 2020 reports that forests provide more than 86 million green jobs. It adds that over 90 per cent of people living in extreme poverty depend on forests for at least part of their livelihoods.

Forest-dependent families use forests for food, fodder, fuel, shelter, medicine and income. When the forest is cleared, these free resources vanish and household income drops. FAO’s 2018 report warns that deforestation threatens the livelihoods of forest communities and indigenous peoples.

For India’s tribal people, NCERT’s Class 11 geography book describes the forest as a home, a livelihood and their very existence. It supplies them with fruits, honey, roots, edible leaves and building materials. Losing it can also erode culture and traditional knowledge.

The wider economy pays a price as well. Silted reservoirs store less water for irrigation and power. Flood damage raises repair costs, and degraded land produces less food.

What are the effects of deforestation in India?

According to ISFR 2023, India’s forest cover rose by 156.41 km² overall compared with ISFR 2021. That national gain hides losses in some places. Madhya Pradesh lost 371.54 km² of forest cover, the biggest fall among the states listed.

The North-Eastern region showed a decrease of 327.30 km² in forest cover. ISFR 2023 links some local losses there to shifting cultivation, known as jhum, in which forest patches are cleared for farming. It also shows a fall in forest cover due to aquaculture in Krishna district, Andhra Pradesh.

The Western Ghats offer another warning. In a ten-year analysis, ISFR 2023 found an overall loss of 58.22 km² of forest cover in the Western Ghats Ecologically Sensitive Area. Moderately dense and open forest shrank there, even though very dense forest grew.

NCERT’s Class 11 geography book traces large-scale forest exploitation in India back to British rule; the drivers are covered in deforestation: meaning and causes.

Can the effects of deforestation be reversed?

Some effects can be reduced, but lost species and eroded topsoil take a very long time to recover. National Geographic notes that deforestation is not always permanent: in parts of North America, forests are returning thanks to conservation. Protecting forests, planting native trees and involving local communities all help. See how to stop deforestation: 12 solutions that work and what is afforestation? for the details.

Sources

• Global Forest Resources Assessment 2025: Key findings (FAO, 2025)
• Global deforestation slows, but forests remain under pressure, FAO report shows (FAO Newsroom, 21 October 2025)
• The State of the World’s Forests 2020: Forests, biodiversity and people (FAO)
• The State of the World’s Forests 2018: Forest pathways to sustainable development (FAO)
• Deforestation (National Geographic Education)
• India State of Forest Report 2023, Volume I (Forest Survey of India)
• NCERT Class 11, India: Physical Environment, Chapter 5 “Natural Vegetation”
• NCERT Class 12 Biology, Chapter 13 “Biodiversity and Conservation”