What Is Deforestation Article

[Tisa Ammann]

Imagesfor download on the MIT News office website are made available to non-commercial entities, press and the general public under a Creative Commons Attribution Non-Commercial No Derivatives license. You may not alter the images provided, other than to crop them to size. A credit line must be used when reproducing images; if one is not provided below, credit the images to "MIT."

Deforestation is a major contributor to climate change, producing between 6 and 17 percent of global greenhouse gas emissions, according to a 2009 study. Meanwhile, because trees also absorb carbon dioxide, removing it from the atmosphere, they help keep the Earth cooler. And climate change aside, forests protect biodiversity.

But deforestation is often financially profitable, so it continues at a rapid rate. Researchers can now measure this trend closely: In the last quarter-century, satellite-based technology has led to a paradigm change in charting deforestation. New deforestation datasets, based on the Landsat satellites, for instance, track forest change since 2000 with resolution at 30 meters, while many other products now offer frequent imaging at close resolution.

Indeed, as Balboni and Olken emphasize, deforestation is now rampant partly because the profits from chopping down trees come not just from timber, but from replacing forests with agriculture. In Brazil, deforestation has increased along with agricultural prices; in Indonesia, clearing trees accelerated as the global price of palm oil went up, leading companies to replace forests with palm tree orchards.

Instead of taxing people for clearing forests, governments can pay people to keep forests intact. The UN uses Payments for Environmental Services (PES) as part of its REDD+ (Reducing Emissions from Deforestation and forest Degradation) program. However, it is similarly tough to identify the optimal landowners to subsidize, and these payments may not match the quick cash-in of deforestation. A 2017 study in Uganda showed PES reduced deforestation somewhat; a 2022 study in Indonesia found no reduction; another 2022 study, in Brazil, showed again that some forest protection resulted.

Some places have tried cash transfer programs for larger populations. In Indonesia, a 2020 study found such subsidies reduced deforestation near villages by 30 percent. But in Mexico, a similar program meant more people could afford milk and meat, again creating demand for more agriculture and thus leading to more forest-clearing.

Also, intriguingly, a 2008 policy change in the Brazilian Amazon made agricultural credit harder to obtain by requiring recipients to comply with environmental and land registration rules. The result? Deforestation dropped by up to 60 percent over nearly a decade.

How precisely politics matters may depend on the context. In a 2021 paper, Balboni and Olken (with three colleagues) found that deforestation actually decreased around elections in Indonesia. Conversely, in Brazil, one study found that deforestation rates were 8 to 10 percent higher where mayors were running for re-election between 2002 and 2012, suggesting incumbents had deforestation industry support.

Looking ahead, Balboni and Olken also suggest that new research estimating the value of intact forest land intact could influence public debates. And while many scholars have studied deforestation in Brazil and Indonesia, fewer have examined the Democratic Republic of Congo, another deforestation leader, and sub-Saharan Africa.

Deforestation is an ongoing crisis. But thanks to satellites and many recent studies, experts know vastly more about the problem than they did a decade or two ago, and with an economics toolkit, can evaluate the incentives and dynamics at play.

Figure 1. Latitude of net zero biophysical effect of forests on local temperature varies from 30 to 56N. Above the line, forest cover causes local warming; below the line, forest cover causes local cooling. The thickness of the line indicates the number of studies that show forest cooling up to that threshold. Data sources as indicated.

Table 1. Forest effects on global temperature in modeling experiments from biogeochemical (CO2) versus biophysical impacts (albedo, evapotranspiration and roughness as well as changes in atmospheric and ocean circulation, snow and ice, and clouds).

Figure 3. Local temperature change in response to deforestation by season and time of day in the various climate zones as determined by comparing neighboring forested and open land (space for time approach) or measuring forest change over time. Warm/dry season response, averaged over the entire diurnal cycle, in red shading and cold/wet season response in blue shading. Daytime response, averaged over the entire annual cycle, in yellow shading and nighttime response in gray shading. See Supplementary Information 3 for data sources.

Figure 4. Effect of complete deforestation on local annual temperature by climate factor, averaged across the land surface within a 10 latitudinal band. Complete deforestation was implemented globally and analyzed by 10 latitudinal bands (Davin and de Noblet-Ducoudr, 2010). The CO2 effect was determined from total aboveground biomass in each 10 band after Walker et al. (2020) and scaled by CERA-derived sensitivity by latitude. Inset distinguishes the sum of all local biophysical effects from local CO2 effects.

Copyright 2022 Lawrence, Coe, Walker, Verchot and Vandecar. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Deforestation is the clearing, or cutting down, of forests. The word is normally used to describe the actions of humans in removing forests from the planet, rather than destruction caused by such natural events as hurricanes.

People have been cutting down trees for thousands of years. In recent times, however, the number of forests being lost through deforestation has grown enormously. This is seen as a great problem that affects the environment in many important ways.

Experts estimate that about 500,000 square miles (1.3 million square kilometers) of land is deforested every 10 years. Half of that is primary forest, which means it has never been cut down before. The largest amount of deforestation is happening in tropical areas, where rainforests are being cut down. Most deforestation is permanent. Some areas do recover from this damage, but it can take many years.

In some countries, especially in tropical areas and in Southeast Asia, farmers cut down large trees and then set fire to areas of a forest to kill off all the animals and plants living there. The ash from the fire helps to fertilize the land, and crops can be grown for a few years before the land becomes useless. The farmers then leave the area and move to a new place. This traditional method of deforestation is called slash and burn.

Deforestation on steep mountain hillsides can lead to erosion. The land can get worn away because the trees are not there to hold the soil together. Heavy rains in such areas can wash the land down the slopes in disastrous landslides that destroy fields, homes, and human lives.

Forests are home to an enormous range of living things. When an area is deforested, many plants and animals are killed. Others lose their habitats. Some types of living things become extinct because of deforestation, especially those that live in tropical rainforests. The traditional way of life for rainforest peoples can be greatly affected by deforestation.

Choose a language from the menu above to view a computer-translated version of this page. Please note: Text within images is not translated, some features may not work properly after translation, and the translation may not accurately convey the intended meaning. Britannica does not review the converted text.

After translating an article, all tools except font up/font down will be disabled. To re-enable the tools or to convert back to English, click "view original" on the Google Translate toolbar.

Deforestation is the clearing, destroying, or otherwise removal of trees through deliberate, natural, or accidental means. It can occur in any area densely populated by trees and other plant life, but the majority of it is currently happening in the Amazon rainforest.

The loss of trees and other vegetation can cause climate change, desertification, soil erosion, fewer crops, flooding, increased greenhouse gases in the atmosphere, and a host of problems for Indigenous people.

Deforestation occurs for a number of reasons. The most common reason is agriculture, with 80% of deforestation resulting from extensive cattle ranching, and logging for materials and development. It has been happening for thousands of years, arguably since people began converting from hunter/gatherer to agricultural based societies, and required larger, unobstructed tracks of land to accommodate cattle, crops, and housing. However, after the onset of the modern era, it became an epidemic.

One of the most dangerous and unsettling effects of deforestation is the loss of animal and plant species due to their loss of habitat. 70% of land animals and plant species live in forests. Not only does deforestation threaten species known to us, but also those unknown.

The trees of the rainforest that provide shelter for some species also provide the canopy that regulates the temperature. Deforestation results in a more drastic temperature variation from day to night, much like a desert, which could prove fatal for many inhabitants.

In addition to the loss of habitat, the lack of trees also allows a greater amount of greenhouse gases to be released into the atmosphere. Healthy forests absorb carbon dioxide from the atmosphere, acting as valuable carbon sinks. Deforested areas lose that ability and release more carbon.

3a8082e126