The biggest downside to biofuels: land and food pressures that can erase climate gains

The biggest downside to biofuels is their land-use footprint—growing fuel crops competes with food production and can drive deforestation or habitat conversion, so the resulting indirect land-use change often cancels out much of the climate benefit. While biofuels can lower tailpipe emissions and help decarbonize hard-to-electrify sectors, their net impact depends heavily on what land is used, how crops are grown, and what would have happened to that land otherwise.

Why land use is the central drawback

Arable land is finite, and dedicating it to energy crops creates trade-offs. When fields or forests are diverted to fuel production, food production shifts elsewhere or expands into new areas, a dynamic known as indirect land-use change (ILUC). The carbon released from clearing forests, peatlands, or grasslands can take years to decades to “repay” with cleaner fuel use, and biodiversity losses can be irreversible. Compounding this, biofuels deliver relatively little usable transport energy per hectare compared with alternatives: analyses consistently find an order-of-magnitude (10–100x) more driving per hectare from solar-powered electric vehicles than from first-generation biofuels like corn ethanol.

The following points outline how biofuel demand translates into land-use change and why that matters.

• Expansion into carbon-rich ecosystems: New cropland for oil palm, soy, or sugarcane can replace forests or peatlands, releasing large carbon stocks and harming biodiversity.
• Displacement effects: When existing cropland shifts from food to fuel, food production may move into new areas, indirectly causing deforestation elsewhere.
• Intensification pressures: Higher commodity prices spur greater fertilizer and pesticide use to boost yields, increasing nitrous oxide (a potent greenhouse gas) and water pollution.
• Long carbon payback times: The “carbon debt” from land conversion can take a decade to many decades to offset, depending on the ecosystem and crop yields.

Taken together, these mechanisms explain why land is the binding constraint: even if a particular farm is efficient, the system-wide response to increased biofuel demand can undermine climate and conservation goals.

Climate implications: lifecycle emissions vary widely

Biofuels’ greenhouse-gas performance depends on the entire lifecycle: farming, fertilizer, transport, processing, and land-use change. Without ILUC, several fuels show moderate to strong reductions versus fossil fuels. When ILUC is included, some common pathways can approach parity with—or exceed—the emissions of the fossil fuels they replace. Debates remain active in 2024–2025 over modeling assumptions and observed land-use outcomes.

Below is a snapshot of typical feedstocks and their indicative risks and benefits based on recent literature and policy assessments.

• Corn ethanol (U.S.): Often shows modest GHG reductions versus gasoline if ILUC is excluded; with ILUC, results range from near-parity to worse than gasoline in some studies. Fertilizer-related nitrous oxide is a key factor.
• Sugarcane ethanol (Brazil): Generally lower emissions than corn due to higher yields and co-generation from bagasse; ILUC risk persists where expansion displaces pasture or native vegetation.
• Soy biodiesel: Can reduce tailpipe particulates but has substantial ILUC risk, especially where soy expansion displaces forests or savannas.
• Palm oil biodiesel: High ILUC risk tied to deforestation and peat drainage; the EU has classified palm-based biodiesel as high ILUC-risk and is phasing it down toward 2030.
• Used cooking oil and waste animal fats: Typically strong GHG benefits with low land-use pressure; supply is limited and increasingly contested across regions.
• Cellulosic fuels from residues (e.g., corn stover, forestry residues): High potential GHG benefits if harvested sustainably and if soil carbon is maintained; commercial scale-up has been slow.
• Algae and novel feedstocks: Technically promising but not yet commercial at scale; land and water footprints depend on system design.

The bottom line: feedstock choice and accounting for land-use change determine whether a biofuel achieves real climate gains. Robust, transparent lifecycle analysis is essential for credible policy and investment.

Food security and price volatility

Diverting cropland to fuel can tighten global food supplies and raise prices, with disproportionate impacts on low-income consumers. The “food versus fuel” tension has been evident during past commodity price spikes when biofuel mandates kept demand high even as supplies tightened. In the U.S., roughly one-third to two-fifths of the corn crop goes to ethanol annually (some returns to the feed market as distillers grains), underscoring the scale of the linkage between energy policy and food markets.

Water, soil, and biodiversity pressures

Beyond GHGs, large-scale biofuel agriculture can stress local ecosystems. Irrigation-intensive crops heighten water scarcity; fertilizer runoff contributes to algal blooms and dead zones; and monocultures can degrade soils and reduce habitat complexity.

The following list summarizes key environmental externalities associated with biofuel expansion.

• Water use and quality: Irrigation demand in water-stressed regions and nutrient runoff that impairs rivers, lakes, and coastal zones.
• Soil health: Increased erosion and loss of soil organic carbon if residue removal or tillage is not managed carefully.
• Biodiversity loss: Conversion to monocultures fragments habitats and reduces species richness, especially in tropical and subtropical regions.
• Air quality trade-offs: Ethanol blends can raise acetaldehyde emissions; some biodiesel blends may increase NOx without modern controls, though they can reduce particulates.
• Agrochemical dependence: Higher pesticide and herbicide use can affect pollinators and non-target species.

These impacts vary by region, crop, and practice, but they compound the core land-use concern and must be managed to avoid shifting burdens from climate to local environments.

Scalability limits and where biofuels still fit

Global volumes of truly low-ILUC, sustainable biofeedstocks are limited. Advanced cellulosic technologies and sustainable aviation fuels (SAF) are progressing but remain supply constrained and costlier than fossil counterparts. Given land and feedstock limits, biofuels are best targeted where alternatives are hardest today.

The points below identify the niches where biofuels tend to deliver the greatest value with the least land pressure.

1. Waste- and residue-based fuels: Used cooking oil, tallow, municipal solid waste, and forestry residues offer high climate value with minimal land-use expansion.
2. Cellulosic fuels from agricultural residues: Careful, site-specific harvesting of corn stover or wheat straw can avoid soil carbon losses while supplying feedstock.
3. Aviation and maritime: Drop-in fuels help decarbonize sectors that are difficult to electrify in the near term, especially when made from wastes and residues.
4. Renewable gas and diesel from wastes: Anaerobic digestion and hydrotreatment can leverage existing waste streams to displace fossil fuels.
5. Cover crops and perennials on marginal land: Limited potential but can deliver soil and habitat benefits if they do not displace existing production.

Focusing limited sustainable feedstocks on the toughest-to-abate uses maximizes climate benefit while minimizing land and food-system tensions.

How to reduce the downside

Policymakers and industry can materially cut biofuels’ land risk by tightening sustainability criteria, improving traceability, and rewarding fuels based on verifiable carbon intensity. Recent moves—such as EU restrictions on high ILUC-risk feedstocks and performance-based credits in U.S. programs—reflect this shift, but enforcement and data quality are crucial.

The following measures are widely cited as effective levers to align biofuel use with climate and conservation goals.

1. Cap or phase down high ILUC-risk fuels: Limit crop-based biodiesel from palm and other risky feedstocks; prioritize wastes and residues.
2. Protect high-carbon and high-biodiversity lands: Enforce no-deforestation and no-conversion rules, including peatlands and native grasslands.
3. Use robust lifecycle accounting: Include ILUC and nitrous oxide; reward continuous improvement and verifiable supply chains.
4. Invest in alternatives: Scale electrification for light-duty transport and support e-fuels where renewable power is abundant.
5. Improve agricultural practices: Precision fertilizer use, cover cropping, reduced tillage, and better water management to lower emissions and runoff.
6. Strengthen traceability: Certification, satellite monitoring, and digital chain-of-custody to prevent leakage and greenwashing.

These tools won’t eliminate all risks, but they materially improve the odds that biofuels deliver genuine, durable climate benefits without worsening land or food pressures.

Summary

The primary downside to biofuels is their land-use footprint: competition with food and the risk of deforestation and habitat conversion can negate climate gains and harm biodiversity. While certain pathways—especially those based on wastes, residues, and carefully managed cellulosic feedstocks—can be climate-positive, sustainable volumes are limited. The most prudent course in 2024–2025 is to reserve scarce, low-ILUC biofuels for hard-to-electrify sectors like aviation, tighten sustainability rules (including ILUC accounting and no-deforestation safeguards), and accelerate electrification and other zero-carbon options wherever feasible.

What are the downsides of biofuels?

Disadvantages of biofuels include deforestation, loss of biodiversity, increased food prices and potential food shortages, significant land and water requirements, high production costs, and the release of air pollutants like nitrogen oxides and fine particles that negatively impact public health and contribute to smog. Furthermore, the energy required for biofuel production and transport can be substantial, sometimes even exceeding the energy content of the fuel itself, and the quality and efficiency of these fuels can vary. 
Environmental & Land Use Concerns

• Deforestation and Habitat Loss: Opens in new tabGrowing crops for biofuels requires large amounts of land, which can lead to deforestation and destruction of natural habitats, reducing biodiversity. 
• Water Consumption: Opens in new tabBiofuel crop production often demands substantial water resources for irrigation, potentially straining local water supplies and disrupting ecosystems. 
• Soil Erosion: Opens in new tabLarge-scale monoculture farming for biofuels can lead to soil erosion and degradation. 
• Air Pollution: Opens in new tabBurning biofuels releases air pollutants, including fine particulate matter, ozone, and nitrogen dioxide, which can trigger respiratory problems, heart attacks, and contribute to smog. 

Socioeconomic Impacts

• Food Prices and Shortages: Opens in new tabUsing land to grow biofuel crops reduces the amount of land available for food production, which can drive up food prices and potentially lead to food shortages. 
• High Production Costs: Opens in new tabSignificant investments in infrastructure and technology are needed to produce biofuels, making them more expensive than traditional fossil fuels. 

Energy and Production Issues

• Production Energy Use: The process of producing, transporting, and refining biofuels can consume a large amount of energy, sometimes to the point where the energy input is not significantly less than the energy output. 
• Variable Quality and Efficiency: The quality of biofuels can vary depending on the feedstock and production process. Additionally, some biofuels are less efficient than other fuels, releasing more heat and less usable energy. 
• Technical Challenges: High-ethanol biofuels may require modifications to car engines, and higher blends of biodiesel can gel in cold weather, limiting their use. 

What are 5 disadvantages of biodiesel?

Cons of Biodiesel:

• Tailpipe Emissions. Assets that run on biodiesel still have tailpipe emissions.
• Can be More Expensive. The cost of biodiesel depends on the blend level and the feedstocks.
• Gels in Cold Weather. Higher blends of biodiesel gel in the engine in cold weather.
• Not Available Everywhere.

Why don’t we use biofuel?

Biofuels cost more to produce than fossil fuel. They tend to consume more resources and energy to produce. Many divert water and land from food production and some consume more energy than they yield.

Is biofuel reliable or unreliable?

The reliability of biofuels as an energy source depends on a variety of factors, such as the feedstocks used, the production methods employed, and the end-use of the biofuels. In general, biofuels can be a reliable energy source if they are produced and used in a responsible and sustainable manner.