The effects of deforestation on humans, the environment and biodiversity

ByDaniil Filipenco

The effects of deforestation on humans, the environment and biodiversity

Every year a massive number of trees are chopped down throughout the world. At the same time, data shows that this is being done at a pace that is considerably faster than reforestation efforts. It is believed this disparity will cause significant damage to the planet.

Forest loss contributes to climate change as well as biodiversity loss which plays an important role in the environment. This in turn impacts humans’ health and wellbeing.

Forests are home to numerous creatures and a plethora of unique plant species. Moreover, forests absorb the excess of carbon dioxide (CO2) from the atmosphere.

Many actions have been taken to bring a halt to forest devastation. Years of dedicated work by environmental activists, lawmakers, and even some corporations are beginning to bear fruit but there is still much more to be done.

The effects of deforestation on humans

The trees that are cut down somewhere far away from where we live might seem to have little impact on our lives but the reality differs because deforestation affects people’s health, livelihoods, and food.


Forest destruction forces animals to migrate. This considerably increases the chances of contact between humans and animals which in turn can lead to the spread of zoonotic diseases.

In 2023 there were reports of zoonotic disease outbreaks in East Africa including the Ebola epidemic in Uganda at the beginning of the year and the Marburg virus breakout in Tanzania in March. These viruses lead to serious ill health and frequently result in high death rates.

Examples of zoonotic diseases:

  • Mosquitoes transmit malaria to people and mosquito populations thrive as biodiversity declines. According to a 2020 research, deforestation increases the chances of malaria spreading
  • A 2017 research connected the outbreak of Ebola in Central and Western Africa to forest destruction
  • SARS-CoV2, the virus responsible for COVID-19, is thought to have migrated from animals to people

To deal with this issue, a 2021 study from the Harvard School of Public Health proposed altering agriculture methods and safeguarding our forests.

Human encounters with diseases such as brucellosis, bovine tuberculosis, and salmonellosis have been significantly reduced in many countries thanks to control measures to deal with diseases that affect poultry and farm animals.

Vaccinations against some illnesses, such as rabies, routine testing for intestinal parasites and other infections together with disease control procedures are examples of additional preventative measures that aim to protect animals.

Food scarcity

  • Native people obtain food and medicine directly from forest plant species or grow crops in fertile soil. Deforestation, the main reason for which is to free up land for conventional agriculture, deprives these people of the resources they need to cultivate food to survive which leads to food insecurity.
  • To feed the rising populations of cities, conventional agricultural producers transform forests into land that can be used for livestock grazing or palm oil and soy production. As a result, the landscapes lose biodiversity and fertility which ultimately makes them unsuitable for long-term food production.

Displaced locals

According to the International Union for the Conservation of Nature (IUCN), roughly a quarter of the planet’s population depends on forests. Native communities around the world face some of the most serious consequences of forest loss with deforestation forcing entire villages to relocate.

Effects of deforestation on the environment

Soil erosion

Tree roots help to stabilize and hold soil in place but the removal of trees loosens the earth and exposes it to destructive rains and wind. Deforestation thus accelerates soil erosion.

In Iran, researchers investigated the effects of deforestation on loess (a mineral-rich soil layer composed of dust and silt). They discovered that agriculture, livestock grazing, and wood usage all contributed to deforestation in the northeastern region of the country which led to the loss of soil and nutrients.

Global warming

Trees help to keep the world’s CO2 levels in check as the gas circulates through the air, oceans, and earth. Deforestation releases the stored gas back into the atmosphere thus contributing to global warming.

If deforestation was brought to an end today, this could lead to an annual reduction in greenhouse gas emissions by 10%. Climate experts say that in order to ameliorate the climate change issue, people need to reduce the level of greenhouse gas emissions by half over the next 20 years or reduce the detrimental effects of forestry industry activities.


Trees help with flood control. During intense rainfall, their roots hold the soil in place and at the same time absorb some of the rainwater. A few examples:

  • While the Philippines was originally heavily forested, a ‘slash-and-burn’ agricultural approach, illegal logging, and open-pit mining, as well as population expansion have destroyed most of the country’s forests.

Low-lying parts of Manila, which has a population of over 13 million people, are frequently flooded when storms strike the Sierra Madre mountain range which previously served as a barrier against the harsh storms.

In October 2022, the Philippine President blamed years of deforestation for the tragic mudslide that obliterated a mountaintop community during heavy rainfall, causing over 130 fatalities.

  • Hundreds of people were killed by flooding in Haiti in 2004. According to reports in the aftermath of the catastrophe, the flooding was caused by the loss of 98% of the forests in the region. This catastrophe was classified as a “man-made ecological disaster.”
  • In 2015, deforestation for illicit harvesting exacerbated floods in Kashmir, killing 18 people.

Effects of deforestation on wildlife

Since 1990, various industries have been cutting down forest areas for farming, grazing, mining and urbanization. This means that billions of creatures have lost their habitat.

Source: FAO
  • Around 50% of all life on land inhabits rainforests. According to data from the United Nations Food and Agriculture Organization (FAO) around 80% of all amphibious species, 75% of birds, and almost 70% of mammals live in rainforests. Every day, habitat damage leads to the extinction of 135 plants, animals, and insects.
  • The harpy eagle, the world’s biggest eagle species, depends on forest cover to seek food. Some harpy eagles have perished from malnutrition due to the lack of such cover.
  • Deforestation has also been linked to the extinction of monarch butterflies that pollinate numerous wildflowers as well as serve as a vital food source for tiny animals.
  • Orangutans can only be found in Sumatra and Borneo. These islands are heavily covered in the world’s most diversified rain forests, most of which remained intact but as a result of palm oil exploitation, a large area of these forests has now been destroyed. Orangutans saw a 25% population reduction in around 10 years owing mostly to deforestation in their natural habitat.

The effects of deforestation in the Amazon

If we take into account the data shared by the World Resources Agency, tropical trees offer around 23% of the climate mitigation that will be required to balance climate change in the following decade. Deforestation leads to disastrous consequences in the Amazon region, home to world’s largest forests, including:

  • Droughts and wildfires – on a normal day, the Amazon spews 20 billion tons of humidity from trees into the air, filling the clouds with rain. Damage to these trees causes droughts and increases in temperatures since more light penetrates the land
  • Decreased biodiversity – deforestation could lead to the extinction of 10,000 species in tropical forests

See also: Why is biodiversity important and how does it help us survive?

  • Habitat destruction – cutting down rainforests can harm habitat, reducing biodiversity and food sources and contaminating rivers and lands.
  • Pollution – fewer trees means fewer natural filters for pollutants.

What’s next?

The destruction of forests around the globe poses a risk not only to wildlife but to multiple ecosystems, with an impact on our health and an acceleration in global warming. Although the forest conservation programs of various nations have led to an increase in forest areas, this is currently not enough. Such efforts need to multiply with more countries engaging in saving forests and planting new trees, thus forming new ecosystems and new habitats for various animals and plants.