Forests do more than shelter wildlife—they shape the air we breathe. When forests are cleared or degraded, air quality can worsen in multiple ways: fewer natural “filters” in the landscape, more dust from exposed soils, and higher wildfire and smoke risk in some regions.
Forests are cleared for agriculture, logging, and urban expansion. The world lost an estimated 26 million hectares of natural forest in 2024, an area roughly the size of New Zealand (1)(2). Almost 500 million hectares of forest have been lost since 1990 (3).
This loss impacts both biodiversity and air quality, as forests have been said to act as “the planet’s lungs,” filtering pollutants, absorbing carbon dioxide and converting it to oxygen (4). Forest loss can remove natural buffers that help limit smoke, dust, and heat-related air-quality stressors—especially in regions already vulnerable to pollution and extreme weather.
And yet, communities around the globe are proving that forest loss can be reversed, and with it, the air we breathe can be restored. The challenge is urgent, but the solutions are within reach.
How forests affect air quality
Forests influence air quality in two ways: they influence the chemistry of the atmosphere (through carbon and other cycles) and the physics of pollution (through shade, wind patterns, and soil stability).
Through photosynthesis, trees absorb carbon dioxide, a major greenhouse gas, and release oxygen, making the air cleaner for all living things. Forests also act as giant filters, trapping harmful pollutants like nitrogen oxides, sulfur dioxide, and, most effectively, ozone (5).
Urban forests offer a natural shield against pollution – at least, temporarily. Studies show that urban areas with robust tree cover can help reduce PM2.5 impacts (6). As pollutants land on stems, leaves, and forest surfaces, they may be later dissolved in stormwater runoff or get redeposited into the soil (7). However, it should be noted that some particulates may end up reentering the atmosphere.
Forests combat dust, a growing threat in deforested and arid regions.
Forests also combat dust, a growing threat in deforested and arid regions. Trees stabilize soil with their roots and create canopies that reduce wind speeds, preventing dust from being whipped into the air (8). And while tree planting is only one component of important reforestation efforts like Africa's Great Green Wall project, it has arisen as a means of combatting climate change-derived desertification (the gradual loss of fertile soil, leaving land dry and inhospitable) and accompanying increased dust (9).
How forests protect our lungs
Forest protection supports respiratory health in two practical ways.
- Healthier forests can reduce the conditions that drive high-particle events—like dust storms and, in some regions, severe wildfire seasons.
When forest cover is lost, soil is more exposed to wind and dries out faster, making it easier for dust to lift into the air and travel long distances. Healthy forests also help retain moisture in the landscape and moderate local temperatures, which can reduce how quickly vegetation becomes “fuel” and how intensely fires burn when they do occur. - In and around cities, tree cover can modestly improve local conditions (shade, cooling, wind patterns) that influence how pollution forms and lingers.
Trees don’t “solve” urban pollution on their own, but shade and cooling can help lower heat-driven ozone formation during hot, sunny periods. Leaf surfaces can also capture some airborne particles, and trees can act as windbreaks that change how pollution moves through streets—sometimes helping disperse it, depending on the design and local airflow.
This doesn’t mean trees replace clean-energy policy or industrial controls. It means forests are part of the “prevention layer”—helping reduce the frequency and intensity of the air-quality stressors that most directly affect breathing.
Where forests are vanishing and why
Deforestation is proceeding rapidly around the globe, with three regions bearing the brunt of the loss: the Amazon Rainforest, the Congo Basin, and Southeast Asia.
Hotspots of deforestation
- Amazon Rainforest: Sometimes called the "lungs of the Earth," the 6.7 million square mile Amazon rainforest spans eight South American countries and French Guiana. 17% of its original cover has been lost to cattle ranching, corn and soy production, illegal logging, and, to a lesser extent, coco and palm oil production (10)(11). In 2023 alone, deforestation claimed 9,001 square kilometers of the Brazilian rainforest – which was actually a 22% decrease in deforestation when compared to 2022 (12).
- Congo Basin: The world’s second-largest tropical rainforest is shrinking rapidly, with industrial logging, charcoal production, and small-scale shifting agriculture serving as the primary causes of deforestation; mining and forest fires are smaller, yet important contributors. The Congo Basin witnessed an increase of 14.2% in primary forest loss in 2024 compared to 2023 (13).
- Southeast Asia: Roughly 15% of the world’s tropical forests are found in Southeast Asia; the region is losing 1% of its total land area to deforestation each year (14). The problem is particularly acute in Indonesia, where palm oil plantations, logging for wood, paper, and pulp, and land conversion projects have seriously impacted forest cover (15).
Four major forces are fueling this loss:
- Agriculture: Over 80% of global deforestation is driven by the expansion of farmland, particularly for beef, soy, and palm oil.
- Logging: Illegal and legal timber operations continue to strip forests, often for short-term economic gain.
- Urbanization: Cities and roads fragment forests, making them more vulnerable to fires and exploitation.
- Climate change: Rising temperatures and drought can stress forests and increase the likelihood of large fires in some regions, which can worsen smoke and particle pollution.
In North America, Europe, Russia, China, South Asia, and Oceania, forestry and wildfires are dominant causes of deforestation. Agriculture and commodity-driven, permanent deforestation are the primary drivers in Latin America and Africa; forestry practices also play a secondary role to permanent deforestation in Southeast Asia (16)
Where forests are making a comeback
Despite years of deforestation, forests are returning thanks to innovative policies, community action, and a growing recognition of their vital role in cleaning our air.
Hotspots of reforestation
- China: Launched in 1978 to combat desertification, the Great Green Wall project aims to plant 100 billion trees by 2050 (17). So far, over 66 billion trees have been planted, creating a barrier against the Gobi and Taklamakan Deserts’ advancing sands. In 2024, the Taklamakan was officially surrounded by vegetation, stabilizing the desert’s sand dunes and transforming the region into a carbon-absorbing sink (18).
- Ethiopia: Ethiopia planted over 350 million trees on one day in 2019 (19). In July, 2025, the government attempted to double that number with one day of planting (20). These tree-planting days were part of a broader initiative that has seen 20 billion trees planted by 2026, reviving greenery and helping restore degraded land. Though long-term results still need to be independently verified to assess tree survival rates, the initiative hopes to develop more financial opportunities through agricultural gains and to improve soil humidity following dry seasons (21).
- Costa Rica: Once one of the most deforested countries in the world, nearly 60% of Costa Rica is once again covered in forest (22). Through payments for ecosystem services, the country has become a top eco-tourist destination. Up to 60% of the country’s annual 3 million tourists credit Costa Rica’s environment for inspiring their visits. Ecotourism employs 200,000 people and accounts for more than 8% of Costa Rica’s GDP.
Rising temperatures and drought can stress forests and increase the likelihood of large fires in some regions, which can worsen smoke and particle pollution.
These successes aren’t just top-down. For example, in Niger, farmers have regenerated 5 million hectares of land using simple, low-cost techniques like farmer-managed natural regeneration (FMNR), boosting crop yields and improved soil retention (23).
Even cities are stepping up their defense of trees. Medellín, Colombia, the country’s second largest city, transformed its hillsides with 30 "green corridors" of native trees to cut urban heat (24). The project worked to reduce heat so well that Colombian cities Bogotá and Barranquilla adopted the plan; São Paulo, Brazil also expanded their version of the project.
How to protect the forests
The fight to save the world’s forests and the air they clean requires action at every level. Governments hold the power to enact sweeping policies, while individuals can drive change through daily choices and advocacy.
What governments can do
- Enforce anti-deforestation laws.
- Incentivize sustainable land use.
- Invest in reforestation programs.
- Avoid planting monoculture trees and plant vegetation that makes ecological sense for the local environment (25).
- Commit to global agreements on forest preservation (26).
- Also commit to following and enforcing global agreements to address climate change, like the Paris Agreement (27).
What individuals can do
Citizen choices can make a sizeable difference in changing the course of deforestation.
- Support companies that make sustainable products and reduce single-use product purchases.
- Reduce paper and wood consumption.
- Participate in local tree-planting initiatives.
- Support organizations and policies that protect forests (28).
- Check your local AQI during smoke events and support community clean air spaces (schools, libraries, clinics) with filtration and monitoring.
The takeaway
Forests support cleaner air by stabilizing soils, shaping local climate conditions, and reducing some of the drivers of smoke and dust—especially when paired with policies that cut pollution at the source.
The UN International Day of Forests (March 21) is a useful reminder that protecting forests is also an investment in breathable air (29). Whether through smarter land-use policy or everyday choices that reduce deforestation pressure, progress adds up—one landscape at a time.
