Palm oil production drives deforestation, releases massive quantities of greenhouse gases, degrades freshwater ecosystems, compacts soils, and pushes species toward extinction. These impacts are concentrated in the tropical regions of Southeast Asia, Central Africa, and Latin America where oil palms grow, but the consequences ripple outward through global carbon budgets, transboundary air pollution, and international commodity markets. The picture is complicated by the fact that oil palm is far more land-efficient than any competing oilseed crop, meaning that replacing it could shift the same problems elsewhere on an even larger scale.
Deforestation at the Root
The single most visible environmental cost of palm oil is forest loss. Oil palms thrive in exactly the same equatorial band where tropical rainforests stand, and clearing that forest is often the cheapest way to establish new plantations. A large-scale analysis of oil palm expansion in Southeast Asia found that roughly 45% of sampled plantations occupied land that had been forest as recently as 1989.1PubMed Central. The Impacts of Oil Palm on Recent Deforestation and Biodiversity Loss That means nearly half the palm oil landscape in the region was carved directly out of standing forest within a few decades.
The pattern is not uniform. In some areas, plantations expanded onto already-degraded land, former rubber estates, or logged-over secondary forest. In others, intact primary forest was felled. The distinction matters ecologically: primary forests harbor far more biodiversity and store far more carbon than degraded land. But in practice, even conversion of degraded forest represents a loss, because secondary forests still sequester carbon and provide habitat corridors for wildlife. A lifecycle emissions study of palm oil mills in Cameroon found that land conversion alone accounted for about 78% of total greenhouse gas emissions across the entire value chain, dwarfing every other source including mill waste and fertilizer use.2Cleaner and Circular Bioeconomy. Greenhouse gas emissions along the value chain in palm oil producing systems: A case study of Cameroon The act of clearing land is, by a wide margin, where the environmental damage begins.
Peatland Carbon Emissions
Not all deforestation is equal in its climate impact. The worst outcomes occur when oil palm plantations replace tropical peat swamp forests. Peatlands are waterlogged ecosystems that accumulate partially decayed plant material over thousands of years, locking away enormous quantities of carbon. When these areas are drained for agriculture, the peat is exposed to oxygen and begins decomposing, releasing carbon dioxide steadily for years or decades.
Researchers measuring carbon fluxes at oil palm plantations on former peat swamp in Southeast Asia found that freshly converted sites emitted roughly 138 tonnes of CO₂ per hectare per year during the initial conversion period. Emissions dropped as the palms matured and absorbed more carbon into their biomass, falling to about 18 tonnes of CO₂ per hectare per year at a mature plantation. But even at those reduced rates, the system remained a net carbon source to the atmosphere after 12 years, and the remaining years of a typical 20-year planting cycle were unlikely to recoup the losses.3PubMed. Short- and long-term carbon emissions from oil palm plantations converted from logged tropical peat swamp forest In other words, a peatland palm oil plantation never pays back its carbon debt within its productive lifetime.
Fire makes things worse. Slash-and-burn clearing, still practiced in parts of Indonesia and Malaysia to prepare land cheaply, adds a spike of emissions on top of the ongoing drainage losses. Research on agricultural tropical peatlands confirmed that burning further increases CO₂ emissions beyond the already-elevated levels caused by drainage alone.4Science of The Total Environment. Oil palm ‘slash-and-burn’ practice increases post-fire greenhouse gas emissions and nutrient concentrations in burnt regions of an agricultural tropical peatland The fires also release particulate matter and other pollutants, creating a separate set of health and environmental problems discussed below.
Transboundary Haze and Human Health
The most dramatic public health consequence of palm oil-related land clearing hit in 2015, when fires set to clear land in Indonesia generated a haze crisis that blanketed much of Southeast Asia for weeks. Researchers estimated that the resulting high concentrations of particulate matter exposed around 69 million people to unhealthy air quality and may have caused roughly 11,880 excess deaths in the short term.5Scientific Reports. Population exposure to hazardous air quality due to the 2015 fires in Equatorial Asia Schools and airports closed across the region, and the economic costs ran into billions of dollars.
The 2015 event was extreme, but smaller-scale haze episodes recur during dry seasons, particularly in El Niño years when drought makes peat more flammable. Indonesia has since tightened enforcement against illegal burning, but the practice persists in remote areas where monitoring is difficult. The health effects fall disproportionately on rural communities living near plantations, who have the least political power to demand change.
Biodiversity Loss Beyond the Headlines
Orangutans have become the public face of palm oil’s biodiversity toll, and with good reason. Forest conversion to monoculture oil palm plantations eliminates both the habitat and the food sources that orangutans depend on, fragmenting populations and increasing conflict with humans. This has contributed to the classification of orangutans as critically endangered.6Jurnal Biologi Tropis. The Expansion of Palm Oil Plantation and the Crisis of Orangutan Habitat in Indonesia: A Literature Review Suitable habitat in key areas of Borneo is now carved up by plantations and community farming, leaving isolated patches that cannot sustain viable populations over the long term.7IOP Conference Series: Earth and Environmental Science. Maxent model application for conflict mitigation of Bornean Orangutan (Pongo pygmaeus wurmbii) in oil palm plantation
But the damage extends far beyond a single charismatic mammal. A broad review of evidence from multiple regions found that oil palm plantations consistently support far fewer species than either primary forest or traditional shifting cultivation landscapes, with birds, understory vegetation, and soil organisms showing the steepest declines.8International Journal of Environment and Climate Change. A Critical Review of Oil Palm Plantations: Effects on Biodiversity with Particular Reference to Mizoram Even seemingly humble creatures matter to ecosystem function. Research in Borneo showed that converting forest to oil palm wiped out entire functional groups of dung beetles, including all dung-rolling species, while shifting the community toward smaller-bodied, less functionally diverse species. The loss of these decomposers reduces nutrient cycling and soil health within plantations.9PubMed Central. Does logging and forest conversion to oil palm agriculture alter functional diversity in a biodiversity hotspot?
An important nuance: logged forests, while degraded, still retain much of their original biodiversity. The jump from logged forest to oil palm plantation is where the sharpest losses occur. This distinction matters for policy, because it suggests that protecting even degraded forest from conversion is far more valuable for biodiversity than allowing the logic of “it’s already logged, so it doesn’t matter” to justify further clearing.
Water Quality and Freshwater Life
Streams running through oil palm landscapes consistently show poorer water quality than those draining forested catchments. A comparison across different land uses in the tropics found that oil palm plantation sites had the lowest water quality scores, the lowest diversity of bottom-dwelling aquatic invertebrates, and the highest abundance of pollution-tolerant species.10Aquatic Sciences. Effect of land use on water quality of tropical headwater streams: comparison across rainforest, cropland, pastureland, and oil palm plantation The combination of fertilizer runoff, sediment from exposed soil, and pesticide drift creates conditions that favor hardy, generalist organisms at the expense of sensitive species.
Oil palm is one of the heaviest consumers of commercial fertilizers in Southeast Asia, relying on a cocktail of nitrogen, phosphorus, and potassium compounds. When rainfall washes these nutrients into streams, the result can be nutrient enrichment and, in severe cases, eutrophication, where excess algal growth depletes oxygen and chokes aquatic life. Retaining strips of natural vegetation along waterways helps filter out nutrients and pollutants before they reach streams.11Limnologica. Effect of riparian management on stream morphometry and water quality in oil palm plantations in Borneo Where these riparian buffers have been cleared to the water’s edge, the damage to stream ecosystems is most severe.
Soil Compaction and Degradation
Beneath the canopy, plantation soils gradually deteriorate. Research comparing soils under oil palm to other tropical land uses found that oil palm soils had lower carbon content, lower nitrogen, and higher bulk density, meaning the soil was more compacted and less porous.12Agriculture, Ecosystems & Environment. Soil degradation in oil palm and rubber plantations under land resource scarcity The compaction worsened with plantation age: soils under 15-year-old palms were significantly more compacted than those under young palms or grassland.13PubMed Central. Soil physicochemical properties change by age of the oil palm crop
This matters for several reasons. Compacted soil absorbs less rainwater, increasing surface runoff and erosion. It holds less organic carbon, reducing the soil’s role as a carbon sink. And it makes the land less productive over time, which can push growers to clear new forest rather than replant on exhausted ground. The degradation is most pronounced in the interrows between palm trees, where heavy machinery passes repeatedly during harvesting.
Mill Waste and Methane
Environmental impacts do not stop at the plantation boundary. Processing oil palm fruit generates palm oil mill effluent, a high-strength organic wastewater. Most mills treat this effluent in open pond systems, where anaerobic decomposition produces methane, a greenhouse gas with far greater short-term warming potential than CO₂. Measurements at treatment ponds have found methane concentrations ranging from 35% to 70% of total biogas output, with individual anaerobic ponds releasing over 1,000 kilograms of methane per day.14PubMed. Baseline study of methane emission from anaerobic ponds of palm oil mill effluent treatment
More detailed spatial mapping of these pond systems has revealed that emissions are extremely uneven, with certain ponds acting as intense hotspots where methane flux can exceed 900 micromoles per square meter per second, coinciding with the points where the most organic matter is being broken down.15Chemosphere. Spatial dynamics of methane emissions and organic load reduction in a pond-based palm oil mill effluent treatment system Capturing this methane for energy, rather than letting it vent to the atmosphere, is one of the more straightforward mitigation options available to the industry. Some mills have installed biogas capture systems, but adoption remains uneven.
How Palm Oil Compares to Other Vegetable Oils
Palm oil’s environmental record looks grim in isolation, but the comparison with alternative oils is more complicated than many consumers realize. Oil palm produces about 3.3 tonnes of oil per hectare on average. Soybean, rapeseed, and sunflower collectively produce their oil at an average of just 0.6 tonnes per hectare, meaning they need roughly five to six times more land for the same output.16Agronomy. Agronomy and Environmental Sustainability of the Four Major Global Vegetable Oil Crops: Oil Palm, Soybean, Rapeseed, and Sunflower Palm oil currently supplies over 90 million tonnes from about 29 million hectares, while the three major annual oilseed crops together produce 121 million tonnes from 191 million hectares.
This land-use efficiency creates a paradox. Modeling studies have found that replacing palm oil with other vegetable oils would keep total greenhouse gas emissions roughly the same while requiring an additional 28 to 52 million hectares of cropland globally, because the replacement crops simply need so much more space.17Science of The Total Environment. Deforestation and greenhouse gas emissions could arise when replacing palm oil with other vegetable oils Even conservative estimates, excluding unlikely deforestation in temperate countries, project 7 to 22 million additional hectares of land conversion. In practice, that means boycotting palm oil without reducing overall vegetable oil consumption could simply relocate the deforestation to other tropical and subtropical regions where soy, coconut, or other oilseeds expand.
This does not absolve palm oil of its harms. It means that the real lever is not which oil is produced but how and where it is produced.
Industrial Plantations Versus Smallholders
Roughly 40% of the world’s palm oil comes from smallholder farmers, and there is a widespread assumption that small-scale producers are inherently gentler on the landscape. The evidence is more mixed than that intuition suggests. A global comparison of environmental impacts found that industrial plantations have historically caused higher forest-loss proportions, greater carbon-loss density, and more peatland conversion per unit area than smallholders.18PubMed. Environmental impacts of global industrial and smallholder oil palm plantations: historical dynamics and future climate risks However, the gap has been narrowing in recent years, with smallholder impacts trending upward toward levels comparable to industrial operations. Losses to protected areas showed no significant difference between the two groups.
The trend matters because future expansion is expected to come increasingly from smallholders, particularly in Africa and Latin America where large concessions are harder to secure politically. If smallholder expansion follows the same trajectory as industrial expansion did decades earlier, the environmental gains from their historically lighter footprint may evaporate.
Does Certification Help?
The Roundtable on Sustainable Palm Oil (RSPO) is the best-known certification scheme, setting standards that prohibit clearing primary forest and high-conservation-value areas. An analysis of RSPO-certified plantations in Indonesia found that certification reduced deforestation rates by about a third compared to uncertified plantations nearby.19PubMed Central. Effect of oil palm sustainability certification on deforestation and fire in Indonesia But the study also uncovered a critical limitation: most plantations had already cleared the vast majority of their forest before seeking certification. By 2015, certified areas in Indonesia held less than 1% of the forests remaining within Indonesian oil palm concessions. Certification also had no measurable effect on peatland loss or fire rates.
Certification carries unintended economic consequences as well. A study of Malaysian plantations found that RSPO certification was associated with decreased production efficiency, meaning certified plantations produced less palm oil per unit of land both before and after certification. The decrease could not be fully explained by market conditions or environmental factors, suggesting it was an unintended side effect of the certification process itself.20PubMed Central. Sustainable palm oil certification inadvertently affects production efficiency in Malaysia If certification lowers yields, it could indirectly increase pressure to expand total planted area, partially undermining the deforestation reductions it achieves.
None of this means certification is useless. It creates accountability mechanisms, shifts industry norms, and provides a market signal. But it is clearly not sufficient on its own as a conservation strategy, particularly when it arrives after most of the damage is already done.
Rewetting Peatlands and Other Restoration Approaches
On the mitigation side, one of the most promising interventions is rewetting drained peatlands. Research comparing drained oil palm plantations to rewetted ones found that blocking drainage canals to raise the water table reduced the decomposition-driven release of CO₂ substantially: heterotrophic respiration dropped by about 34%, and total soil respiration fell by about 20%.21Science of The Total Environment. Strong climate mitigation potential of rewetting oil palm plantations on tropical peatlands Rewetted sites still emitted more carbon than undisturbed swamp forest, but the improvement over drained plantations was significant. Rewetting is not a complete solution, since oil palms do not grow well in waterlogged conditions, but it can be implemented as plantations reach the end of their productive cycle, offering a transition pathway toward lower-emission land use.
Within active plantations, tree-based enrichment planting offers a way to recover some biodiversity without completely abandoning production. Research in Sumatra found that increasing the number of non-palm trees in and around plantations boosted bird diversity and abundance. The relationship was nonlinear: in intensively managed plantations with few trees, adding even a modest number of native trees produced meaningful biodiversity gains at relatively low cost in lost revenue. Costs rose steeply only in already extensively managed plantations where further tree planting competed more directly with palm oil production.22Biological Conservation. Trade-offs between bird diversity and abundance, yields and revenue in smallholder oil palm plantations in Sumatra, Indonesia The finding suggests that enrichment planting in the most heavily industrialized plantations offers the best return for conservation effort.
Zero-Deforestation Frameworks and Where New Expansion Could Go
A growing number of companies and governments have adopted zero-deforestation commitments, but turning those promises into practice requires a tool for distinguishing land that can be developed from land that should remain forested. The High Carbon Stock Approach is one such tool, setting carbon-density thresholds to identify which areas qualify as forest. In Gabon, a heavily forested Central African country where oil palm expansion is under discussion, analysis using this approach found that between 1.2 and 1.7 million hectares of non-forest, non-conservation-priority land could be available for oil palm, depending on the carbon threshold applied. Developing only that land would protect 93% to 99% of Gabon’s existing carbon stocks.23Land Use Policy. Understanding zero deforestation and the High Carbon Stock Approach in a highly forested tropical country
The Gabon example illustrates an important principle: the question is not whether palm oil can be produced without deforestation, but whether the political and economic incentives exist to steer expansion onto degraded or low-carbon land rather than intact forest. In countries with weak governance, land-tenure disputes, and powerful interests in cheap clearance, the technical feasibility of zero-deforestation production matters less than the enforcement capacity on the ground.
Climate Change as a Feedback Loop
Palm oil production contributes to climate change, but climate change also threatens palm oil production in return. Oil palm yields are sensitive to heat and drought, and El Niño events, which bring extended dry spells to much of Southeast Asia, cause measurable drops in production and subsequent price spikes in global markets.24Agronomy. Impact of El Niño on Oil Palm Yield in Malaysia As climate change increases the frequency and intensity of El Niño-Southern Oscillation events, water stress on oil palm is expected to worsen, particularly in regions of Malaysia and Indonesia that already experience periodic drought.25Scientific Reports. Regional water stress dynamics in oil palm under ENSO in Malaysia and Indonesia using 22-year multiple climate data
Reduced yields under climate stress could push producers in two directions. One is intensification: investing in drought-tolerant varieties, better irrigation, and more efficient management to squeeze more oil from existing land. The other is extensification: clearing new land to compensate for declining productivity on existing plantations, restarting the deforestation cycle. Which path dominates will depend on the relative cost of technology versus land, and on whether regulatory frameworks in producing countries can hold the line against expansion into forests during periods of supply shortage.