Deforestation facts for kids

A deforested area

Deforestation is when forests are destroyed by cutting trees (logging) and not replanting them. The most common reason is to clear the land to make farms, ranches, and cities. Trees are also cut for firewood and lumber.

Deforestation destroys the habitat of many animals, leading to their death and possible extinction. The loss is more severe in primary forests, which are forests that have yet been untouched by humans. Deforestation also releases sequestered carbon.

Restoring trees in deforested places is called reforesting.

Benefit of forests

Forests are often planted to protect against natural disasters. They also help the water cycle function properly. When forests are lost, very often the soil they protected is also lost. This loss of soil is called erosion.

Trees are also important for carbon sequestration. They are important in keeping the proper balance of oxygen (O₂) and carbon dioxide (CO₂) on earth. They take in carbon dioxide that humans exhale (breathe out) and release oxygen that humans inhale (breathe in).

Forests have the following functions:

• regulating the water cycle
• producing soil
• preventing soil erosion
• providing habitat for animals
• providing most of our oxygen
• maintaining the proper oxygen (O₂) and carbon dioxide (CO₂) levels
• balancing the atmosphere
• regulating the temperature

History

Global deforestation suddenly increased around 1852. As of 1947, the planet had 5.8 million to 6.2 million sq. mi. (15 million to 16 million km²) of mature tropical forests (forested landscapes in tropical regions), but by 2015, it was estimated that about half of these had been destroyed. Total land coverage by tropical rainforests decreased from 14% to 6%. Much of this loss happened between 1960 and 1990. Scientists have calculated that at this rate, the extinction of such forests could happen by the mid-21st century.

Causes of deforestation

Land has other uses besides growing trees. The biggest uses of land that was once forested are for farming and ranching. Some land is also used for roads and buildings, especially in urban areas. As the population grows, people need to remove more trees. They also use the wood from the trees as lumber to make buildings and other things, or they burn the trees as firewood.

Environmental effects

Atmospheric

Further information: Deforestation and climate change

Biophysical mechanisms by which forests influence climate.

Per capita CO₂2 emissions from deforestation for food production

Illegal "slash-and-burn" practice in Madagascar, 2010

Deforestation is ongoing and is shaping climate and geography.

When the trees burn or rot, the small amount of carbon that is not absorbed by the soil can return to the atmosphere in the form of carbon dioxide. Scientists believe that since carbon dioxide is a greenhouse gas, deforestation can cause global warming. They have estimated that tropical deforestation is responsible for about 20% of world greenhouse gas emissions.

Hydrological

The water cycle is also affected by deforestation. Trees play an important part in the proper working of the water cycle.

• Their canopies catch precipitation, which is then evaporated back to the atmosphere (canopy interception). Without canopy interception, the air would be drier and less precipitation would fall.
• Their litter (plant material on the ground around the tree), stems, and trunks slow down surface runoff. Without these, flash flooding would be more likely.
• Their roots create macropores – large pipe-like trails – in the soil that increase infiltration of water. Without these trails, water would not flow through the soil as easily.
• They absorb groundwater from the soil and transpire moisture into the atmosphere. Without transpiration, the air would be drier and trees would not get the moisture they need because of the lack of precipitation.

Tropical rainforests produce about 30% of our planet's fresh water.

Deforestation changes normal weather patterns, creating hotter and drier weather. This results in more drought, crop failures, melting of polar ice caps, and coastal flooding.

Deforestation of the Highland Plateau in Madagascar has led to extensive siltation and unstable flows of western rivers.

Soil

In an undisturbed forest, the mineral soil is protected by a layer of leaf litter and an humus that cover the forest floor. These two layers form a protective mat over the soil that absorbs the impact of rain drops. They are porous and highly permeable to rainfall, and allow rainwater to slow percolate into the soil below, instead of flowing over the surface as runoff. The roots of the trees and plants hold together soil particles, preventing them from being washed away. The vegetative cover acts to reduce the velocity of the raindrops that strike the foliage and stems before hitting the ground, reducing their kinetic energy. However it is the forest floor, more than the canopy, that prevents surface erosion. The terminal velocity of rain drops is reached in about 8 metres (26 feet). Because forest canopies are usually higher than this, rain drops can often regain terminal velocity even after striking the canopy. However, the intact forest floor, with its layers of leaf litter and organic matter, is still able to absorb the impact of the rainfall.

Deforestation causes increased erosion rates due to exposure of mineral soil by removing the humus and litter layers from the soil surface, removing the vegetative cover that binds soil together, and causing heavy soil compaction from logging equipment. Once trees have been removed by fire or logging, infiltration rates become high and erosion low to the degree the forest floor remains intact. Severe fires can lead to significant further erosion if followed by heavy rainfall.

Globally one of the largest contributors to erosive soil loss in the year 2006 is the slash and burn treatment of tropical forests. In a number of regions of the earth, entire sectors of a country have been rendered unproductive. For example, on the Madagascar high central plateau, comprising approximately ten percent of that country's land area, virtually the entire landscape is sterile of vegetation, with gully erosive furrows typically in excess of 50 metres (160 ft) deep and 1 kilometre (0.6 miles) wide. Shifting cultivation is a farming system which sometimes incorporates the slash and burn method in some regions of the world. This degrades the soil and causes the soil to become less and less fertile.

Biodiversity

Forests support biodiversity, providing a habitat for wildlife. Forests also produce medicinal plants. Tropical rainforests are the most diverse ecosystems on Earth and about 80% of the world's known biodiversity could be found in tropical rainforests. When humans remove or destroy large areas of forest cover, the soil degrades and biodiversity is lessened. Some species of plants and animals can become extinct. Some scientists predict that more than 40% of the animal and plant species in Southeast Asia could be wiped out in the 21st century. Other scientists show data that disagree with this prediction.

Health effects

Public health context

Some scientists believe that deforestation exposes people to zoonotic diseases (diseases that can be passed from an animal to a human). Dieseases that are associated with the forest include malaria, Chagas disease (also known as American trypanosomiasis), African trypanosomiasis (sleeping sickness), leishmaniasis, the Nipah virus, Avian flu, Swine Flu, Lyme disease, HIV, and Ebola.

General overview

According to the World Economic Forum, 31% of emerging diseases are linked to deforestation. According to the US Centers for Disease Control and Prevention (CDC), 75% of emerging diseases in humans came from animals.

In 2016, the United Nations Environment Programme published the UNEP Frontiers 2016 Report. The report shows the causes of emerging diseases:

The latest appearing diseases and their causes are listed on page 23 of the report:

Economic impact

A satellite image showing deforestation for a palm oil plantation in Malaysia

According to the World Economic Forum, half of the global GDP depends on nature. For every dollar spent on nature restoration, there is a profit of at least 9 dollars.

People in both developed and developing countries use wood for building, wood for fuel, and wood pulp for paper. In developing countries, almost three billion people rely on wood for heating and cooking. The economy does well in the short term when trees are cut to make products, but usually, not enough trees can be planted in their place in time for more to be cut down again when they are needed. This causes the economy in the long term to suffer.

Illegal logging causes billions of dollars of losses to national economies each year. The European Union is one of the largest importers of products made from illegal deforestation.

Control

Many countries have taken steps to control deforestation. They have begun programs that they hope will help with the problem.

Transferring land rights to indigenous inhabitants is argued to efficiently conserve forests.

• Reducing emissions: The United Nations and the World Bank have begun to develop programs to reduce deforestation. Because trees take in carbon dioxide, the more trees we have, the less CO₂ will be emitted into the air. Reducing Emissions from Deforestation and Forest Degradation (REDD) is a program that offers money or other incentives (good consequences as a result of an action) to developing countries if they use different ways to build than using the forest's trees.
• Government and private policies: In the government area, laws could be made to protect forests, making it illegal to cut trees down without special permission. Private companies could promise to use the land they own the best way they can and to buy products only from companies that do not use deforestation. The Paris Agreement is an example of this.
• Land rights: Another way to conserve forests is to change the right to use the land from the public domain to the indigenous inhabitants.
• Farming practices: New ways to farm are being developed to get more use out of a single piece of land rather than having to use many pieces of land for different purposes. For instance, in cyclic agriculture, cattle are grazed on farmland that is resting and rejuvenating. The cattle help the land prepare for future plantings by dropping nutrients (from their feces) into the soil.
• Monitoring deforestation: Satellite images can help scientists know where on the earth they need to concentrate their efforts in fighting deforestation.
• Forest management: Planning ahead by planting more trees than we think will be necessary for future generations is one way to manage our forests well. Reforestation in areas where trees have been cut is another way to manage our forests well. In the areas where "slash-and-burn" is practiced, switching to "slash-and-char" would make the soil rich and healthy for future trees.
• Sustainable practices: Bamboo grows and is ready for use faster than trees. Using bamboo rather than wood for building and making products would reduce the need to cut down trees.
• Forest plantations: Some places have forest plantations, which are large plots of land that have trees planted on them in an orderly way. They produce more healthy trees per acre than a natural forest.

Interesting facts about deforestation

• More than half the world’s tropical forests have been destroyed since the 1960s.
• In 2019, the world lost an entire soccer field worth of primary rainforest every six seconds.
• Forests release carbon dioxide when they are cleared or burned. About 12 percent of global greenhouse gas emissions come from deforestation.
• It is estimated that within 100 years, there will be no rainforests.
• 20% of the world’s oxygen is produced in the Amazon forest.
• Almost half of the world’s timber and up to 70% of paper is consumed by Europe, the United States, and Japan alone.
• Worldwide, more than 1.6 billion people rely on forest products for all or part of their livelihoods.

Related pages

• Desertification
• Reforestation

Images for kids

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  Deforestation in New Zealand.

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  Satellite image of deforestation in progress in eastern Bolivia. Worldwide, 10% of wilderness areas were lost between 1990 and 2015.

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  Deforestation of the Amazon rainforest in Brazil's Maranhão state, 2016

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  The last batch of sawn wood from the peat forest in Indragiri Hulu, Sumatra, Indonesia. Deforestation for oil palm plantation.

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  Fires on Borneo and Sumatra, 2006. People use slash-and-burn deforestation to clear land for agriculture.

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  Deforestation of Brazil's Atlantic Forest c.1820–1825

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  Deforestation in Suriname c.1880–1900

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  Deforestation in Venezuela for cattle breeding.

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  Satellite imagery of locations of the 2019 Amazon rainforest wildfires as detected by MODIS from August 15 to August 22, 2019

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  Deforestation in Ecuador.

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  Deforestation in Germany.

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  Timelapse of recent deforestation of the Amazon rainforest

See also

In Spanish: Deforestación para niños