Deforestation is the permanent destruction of forests for non-forest uses like agriculture, housing development, mining or urban use. Deforestation occurs worldwide and has significant environmental and economic impacts. This article explores the causes and effects of deforestation through an examination of recent research on the topic.
One of the primary drivers of deforestation is agricultural expansion to create new lands for crops, livestock grazing or aquaculture. A 2022 study published in the journal Science examined tropical deforestation between 2004-2017 and found that the largest reason for forest loss was conversion to commercial agriculture like oil palm and soybean plantations. The study showed that Brazil, Indonesia and Paraguay accounted for 65% of commercially-driven deforestation globally during that time period. Large-scale cattle ranching is also a major cause of deforestation, especially in Latin America. A 2020 paper in Global Change Biology estimated cattle ranching was responsible for 80% of past deforestation in the Brazilian Amazon.
In addition to commercial agriculture, small-scale subsistence farming by rural communities relying on forest resources for their livelihoods contributes to deforestation globally. Research published in Land Use Policy in 2021 found poverty alleviation programs in rural forest communities that provide alternative sources of income and foods can help reduce pressures on forests from subsistence activities over time. International demand for commodities like palm oil, soy, beef and wood products is also a key indirect driver of deforestation according to a 2020 review study published in Global Environmental Change.
Logging, both legal and illegal, is another substantial cause of deforestation worldwide. A 2021 paper in Scientific Reports analyzed the impacts of selective logging on tropical forests across 15 countries. Results showed selective logging opened up forest canopy cover which increased accessibility for further deforestation and degradation activities by other agents. Researchers estimated selective logging preceded complete forest clearance over 28% of degraded lands within 5 years. Illegal logging is particularly problematic and enables other unsanctioned activities like land grabbing. According to Interpol, illegal logging accounts for 15-30% of all wood production globally.
Infrastructure projects like roads, railways, pipelines and utility corridors are also a major facilitator of forest conversion. A review paper from 2019 in the journal Land Use Policy found road construction in particular expanded the frontier of deforestation far beyond project footprints by improving market access into previously intact forest regions. Hydropower dam construction may not directly clear large areas but according to a 2020 study in Environmental Research Letters, associated transmission line corridors and workforce influx have substantial indirect forest loss impacts. Mining operations have also been linked to deforestation through clearance of mining sites but especially access infrastructure development in sensitive forest zones per a 2018 paper in Journal of Cleaner Production.
Urbanization and housing development are growing direct drivers of deforestation globally, especially near cities in developing nations. A study published in 2022 in the journal Land found that residential and commercial construction caused 31% of deforestation in Peninsular Malaysia between 2015-2020. Similarly, a 2019 paper in the journal Forests estimated future housing demands from expanding urban populations in Colombia could directly impact over 280,000 hectares of forest by 2030 without effective urban planning policies. Unplanned, speculative real estate investments have exacerbated forest loss in several countries as well according to a review paper from 2017 in the journalWorld Development.
Aside from direct drivers, lack of strong governance and enforcement of environmental regulations enable further deforestation pressures, according to research. Analyzing spatial data of forest cover change in Brazil between 2008-2014, a 2019 study published in Geoforum indicated deforestation rates were a full five times higher in areas with low governance compared to areas with strict law enforcement. Weak governance, corruption and lack of coordination among government agencies tasked with managing forests, lands and enforcing regulations impair conservation efforts per a meta-analysis study published in Global Environmental Change in 2020. Conflict over forest lands between government, corporations and indigenous groups without clarity in land tenure rights also leads to greater risks of deforestation found a paper from 2021 in the journal Ecology and Society.
While direct drivers tend to clear forests rapidly, indirect effects from infrastructure and human population density changes can have slow but continuous impacts on forest cover loss studies show. An analysis of nearly four decades of satellite imagery of the Amazon basin published in 2020 in the journal Science Advances revealed up to 40% of deforestation occurred not directly from infrastructure but within 5km of roads and 1km of human settlements. The researchers found the amount of forest converted to non-forest uses annually within these buffer zones grew steadily from 1978 to 2018, demonstrating the gradual influence of accessibility changes. A 2016 study in Environmental Research Letters that compiled historical land cover maps and census data across 12 developing nations found a strong correlation between rises in rural population density and clearing of surrounding forests even after accounting for effects of market access and commercial pressures.
The carbon emissions from tropical deforestation are a major contribution to global climate change, removing a natural carbon sink effect according to research. A paper published in 2021 in the journal Environmental Research Letters estimated global deforestation releases 3-6 billion tons of carbon dioxide per year worldwide. Over a 30-year period from 1980-2010, CO2 emissions from tropical deforestation comprised roughly 20% of the total increase in atmospheric carbon dioxide levels impacting global temperatures. Besides greenhouse gas emissions, large-scale deforestation reduces regional rainfall and increases risks of flooding due to loss of natural drainage functions provided by forests found a 2020 study in the journal Bioscience. Fewer trees to absorb and filter rainfall leads to increased water runoff which has worsened flooding in formerly forested basins in Indonesia, Malaysia and the Philippines per case study research from Forests journal 2019.
Reduced forest cover impacts biodiversity significantly according to science. A review of 120 studies published in Science in 2020 found widespread forest loss and degradation drove population declines of 95% of monitored bird, mammal, reptile and amphibian species in tropical regions. Habitat fragmentation doubles extinction risks for many forest specialist plants and animals according to meta-analysis of over 100 global land use change impact analyses published in Proceedings of the National Academy of Sciences in 2021. Deforestation drives high numbers of species toward endangerment and extinction, especially in biodiversity hotspots research shows. Analysis of global tree surveys data from Kew Botanical Garden published in Nature in 2015 indicated over 3000 tree species alone are threatened by accelerating deforestation in tropical rainforests.
While debates persist over how to balance conservation policies with socio-economic development needs, research consistently demonstrates deforestation carries substantial environmental costs if left unchecked. Reducing deforestation and restoring degraded forest landscapes can help mitigate climate change while sustaining ecosystem services humanity depends on according to studies. Strategies that address both proximate and underlying causes through integrated conservation, land use, poverty alleviation and governance measures show most promise for success in protecting the world’s remaining forests based on synthesis of empirical results. Continued scientific research, monitoring and evaluation will remain essential to guide effective policy and project interventions seeking to curb the ongoing losses of tropical and subtropical forests globally.
Andrew Stroud