Disadvantages of Biofuels: The Hidden Costs Behind “Green” Fuels

Biofuels carry notable drawbacks: land-use change can erase climate gains, they may compete with food production, demand significant water and fertilizers, threaten biodiversity, create air-quality trade-offs, deliver lower energy density and infrastructure challenges, rely on limited feedstocks, and depend on volatile policies and subsidies. While advanced biofuels can mitigate some issues, high costs, feedstock scarcity, and certification risks remain. This article explains where and why these disadvantages arise, and how they vary across biofuel types and regions.

Key disadvantages at a glance

The following list distills the principal drawbacks of biofuels across environmental, technical, and economic dimensions, highlighting where their benefits can be undermined or reversed.

• Land-use change and carbon debt can cancel climate benefits for years or decades.
• Competition with food crops can raise prices and intensify land pressure.
• High water use, fertilizer, and pesticide inputs can degrade water quality and soils.
• Habitat conversion can reduce biodiversity and damage ecosystems.
• Air pollutant trade-offs (e.g., NOx, aldehydes, ozone precursors) can harm health.
• Lower energy density and cold-flow issues reduce performance and reliability.
• Infrastructure incompatibilities (e.g., pipelines, materials) add cost and complexity.
• Feedstock limits constrain scalability; waste streams are finite and contested.
• Economic volatility and reliance on mandates/subsidies create policy risk.
• Certification gaps and fraud risks can mask unsustainable supply chains.

Taken together, these factors mean biofuels are not automatically climate- or eco-friendly; outcomes depend on what is grown, where and how it is produced, and how it is blended and used.

Climate impacts and land-use change

Biofuels are often labeled “carbon neutral,” but this overlooks land-use dynamics. Converting forests, grasslands, or peatlands to grow biofuel crops releases stored carbon, creating a “carbon debt.” Depending on the ecosystem and crop, it can take years to centuries of biofuel use to repay that debt through avoided fossil emissions.

Indirect land-use change (ILUC) can occur when existing cropland is diverted to biofuels and food production expands into new areas, causing additional deforestation elsewhere. Studies have found ILUC can markedly reduce or even negate lifecycle greenhouse gas (GHG) savings. For example, palm oil biodiesel linked to peatland drainage can have higher life-cycle emissions than fossil diesel; soy expansion into tropical regions carries similar risks. Policy responses such as the EU’s restrictions on “high ILUC-risk” feedstocks and national deforestation-free supply laws reflect these concerns.

Food, land, and biodiversity pressures

When biofuel production uses food crops (e.g., corn, sugarcane, soy, palm), it can tighten global grain and oilseed markets, contributing to price volatility. While biofuels are rarely the sole driver of food price spikes, mandates and subsidies can amplify demand during tight markets. In land-constrained regions, increased demand can push cultivation into marginal or biodiverse areas, threatening species and ecosystem services.

Even non-food bioenergy crops (e.g., some grasses or short-rotation woody crops) can displace other land uses, with biodiversity impacts depending on local practices. Monocultures generally support less wildlife than mixed or natural habitats, and large-scale plantations can fragment landscapes.

Water use, soil health, and pollution

Many biofuel pathways require substantial water. Processing corn ethanol typically consumes several liters of water per liter of ethanol, and irrigation needs in arid regions can be far higher. Sugarcane can be rain-fed in some areas but draws heavily on water where irrigation is used. Fertilizer and pesticide use—common in high-yield energy crops—drive nutrient runoff, algal blooms, and soil degradation. Residue removal for cellulosic biofuels, if not carefully managed, can reduce soil organic carbon and increase erosion.

Air quality and health trade-offs

Biofuels change tailpipe emissions in complex ways. Ethanol blends can reduce carbon monoxide and some aromatics but increase emissions of acetaldehyde and, under certain conditions, ozone-forming compounds. Biodiesel typically lowers particulates and carbon monoxide but may increase nitrogen oxides (NOx) depending on engine calibration and blend levels. These trade-offs are highly context-specific and influence urban air quality and public health.

Energy density, operability, and infrastructure challenges

Ethanol has about one-third less energy per liter than gasoline; common blends like E10 reduce fuel economy by roughly 3%, while E85 can drop mileage by around 25–30% in conventional engines. Biodiesel (B100) has slightly less energy than petroleum diesel and can present cold-flow and oxidation-stability challenges; low-temperature gelling risks require additives or heating, and high blends can pose compatibility issues with some seals and hoses.

Infrastructure constraints add cost. Ethanol’s affinity for water and solvent properties limit use of existing petroleum pipelines and storage without upgrades, increasing reliance on rail and trucking. “Blend walls” (e.g., E10/E15 limits in legacy engines and fueling networks) cap near-term market uptake without vehicle and station upgrades. Aviation and marine fuels face even stricter performance and safety requirements, constraining substitution options.

Scalability and feedstock limits

Waste and residue-based feedstocks (e.g., used cooking oil, tallow, agricultural residues) generally deliver better lifecycle performance but are inherently limited in volume and increasingly contested by multiple industries (renewable diesel, sustainable aviation fuel, oleochemicals). As demand rises, supply chains may reach farther afield, inflating transport emissions and inviting fraud or mislabeling. Cellulosic technologies have advanced, yet commercial-scale output has lagged earlier projections due to logistics, pretreatment costs, and technical complexity.

Economics, policy dependence, and market risks

Many biofuel pathways rely on mandates, tax credits, or low-carbon standards to be competitive. This dependence exposes producers and consumers to policy shifts, eligibility rules, and lifecycle accounting methodologies. Recent debates over modeling (e.g., updates to carbon-intensity calculators and land-use assumptions) and regional policies—such as U.S. renewable fuel standards, state low-carbon fuel programs, and evolving EU rules—underscore the uncertainty. When carbon intensity scores or eligibility change, plant economics can swing rapidly, stranding investments.

Certification, traceability, and fraud risks

Sustainability certifications aim to prevent deforestation and ensure traceability, but complex global supply chains can obscure origins, especially for used cooking oil, palm-based feedstocks, or cross-border blending. Auditing challenges and inconsistent standards across jurisdictions can allow leakage, greenwashing, or outright fraud, undermining claimed environmental benefits.

Advanced biofuels: progress, but persistent constraints

Advanced pathways—such as hydroprocessed esters and fatty acids (HEFA) for renewable diesel and sustainable aviation fuel, alcohol-to-jet (ATJ), and Fischer–Tropsch fuels from biomass—can deliver substantial GHG reductions when fed by genuine wastes and residues. However, they remain limited by feedstock availability, high capital costs, and competition with other decarbonization options (notably electrification for road transport and emerging e-fuels for aviation). As countries implement aviation SAF mandates (e.g., Europe’s ReFuelEU Aviation) and revise crediting schemes, scarcity of suitable feedstocks is a central bottleneck and cost driver.

When biofuels do the most harm

The situations below are red flags indicating that a biofuel pathway is likely to underperform or even worsen environmental outcomes compared with fossil fuels.

• New cultivation replaces forests, peatlands, or biodiverse grasslands.
• Food crops are diverted to fuel in land- or water-stressed regions.
• High fertilizer and irrigation inputs are required to maintain yields.
• Long, opaque supply chains without robust, verifiable certification exist.
• Cold climates or legacy engines require high-cost modifications to operate blends.

While not exhaustive, these conditions often correlate with higher lifecycle emissions, ecological harm, and social risks, signaling caution for investors and policymakers.

Bottom line

Biofuels can cut emissions in specific niches, but their disadvantages are substantial when they drive land-use change, compete with food, strain water resources, worsen local air quality, or depend on scarce feedstocks and unstable policies. Robust safeguards, transparent accounting, and prioritizing true wastes and residues are essential—yet even then, scalability remains limited, and alternatives like electrification often deliver clearer, faster climate benefits in road transport. Biofuels’ most defensible roles are likely to be targeted: hard-to-electrify sectors (aviation, marine) and genuine waste-based pathways with strict oversight.

Summary

Major disadvantages of biofuels include potential land-use change that erases climate gains, food-versus-fuel tensions, high water and chemical inputs, biodiversity loss, air pollutant trade-offs, lower energy density and operability issues, infrastructure constraints, limited and fraud-prone feedstocks, and heavy dependence on policies. Advanced biofuels mitigate some issues but remain constrained by cost and scale. Careful pathway selection and strict safeguards are required—and even then, biofuels are not a universal decarbonization solution.

Is biofuel expensive?

In recent years, biofuels have consistently been more expensive compared to fossil fuels in Europe. With the current price hikes in many of the feedstocks used for biofuels like vegetable oils, cereals, used cooking oil and animal fats, the price difference to fossil fuels is becoming ever larger.

What are the advantages of biofuels?

The main advantages of biofuels are that they are a renewable energy source, reduce reliance on fossil fuels, and can lower greenhouse gas emissions compared to petroleum products. Biofuels also boost energy security by providing a domestic energy source, create economic opportunities in rural communities, and can be produced from a variety of materials, including waste products.
 
Environmental Benefits

• Renewable and Sustainable: Opens in new tabUnlike finite fossil fuels, biofuels are made from biological materials like plants and waste, which can be replenished and are sustainable. 
• Reduced Greenhouse Gases: Opens in new tabThe production and use of biofuels can lead to lower net greenhouse gas emissions, as the carbon released during combustion is balanced by the carbon dioxide absorbed by the plants during their growth cycle. 
• Biodegradable: Opens in new tabBiofuels are generally non-toxic and biodegradable, making them less harmful to the environment than petroleum-based fuels. 

Economic and Social Benefits

• Energy Independence: Opens in new tabUsing domestic biofuels reduces a country’s dependence on foreign oil, enhancing energy security and national security. 
• Economic Development: Opens in new tabBiofuel production can create jobs in agriculture, engineering, and transportation, especially benefiting rural communities and farmers. 
• Support for Rural Economies: Opens in new tabThe demand for crops used in biofuel production can increase farm incomes and support local rural economies. 

Operational and Technical Benefits

• High-Quality Engine Performance: Opens in new tabBiofuels can often be used in existing engines with little to no modification, and some studies show they can improve engine performance and longevity. 
• Diversified Energy Supply: Opens in new tabThe use of biofuels diversifies the energy supply, making the overall energy system more resilient. 
• Waste Utilization: Opens in new tabBiofuel production can utilize agricultural waste and byproducts, transforming them into valuable energy sources and reducing waste. 

What are five disadvantages of biofuels?

Disadvantages of biofuels

• Impact on drive units.
• Less energy efficiency.
• Increase in food prices.
• Risk to biodiversity.
• Water demand.
• Degradation of natural habitats.
• Technical problems.

What are the negative effects of biofuels on the environment?

Biofuels harm the environment through factors including: significant land use changes and deforestation, which create a “carbon debt” and impact biodiversity; heavy use of fertilizers and pesticides, which pollute water and contribute to emissions of the potent greenhouse gas nitrous oxide; release of hazardous air pollutants and ground-level ozone during production and combustion; and potential negative impacts on water resources due to irrigation and pollution from processing.
 
Land Use and Deforestation 

• “Carbon Debt”: Opens in new tabCreating farmland for biofuel crops, especially by clearing forests, releases stored carbon into the atmosphere, creating a “carbon debt”. The carbon released may not be recovered by the biofuel for decades, if ever, making some biofuels worse than fossil fuels. 
• Biodiversity Loss: Opens in new tabLarge-scale cultivation of biofuel crops replaces natural habitats like forests and prairies, leading to a loss of biodiversity and threatening endangered species. 

Pollution and Greenhouse Gas Emissions 

• Fertilizer Use: Opens in new tabGrowing biofuel crops requires substantial amounts of fertilizers. Excess fertilizer runs off into waterways, contaminating ground and surface water and increasing eutrophication. 
• Nitrous Oxide (N₂O) Emissions: Opens in new tabMicrobial action converts excess nitrogen fertilizer into N₂O, a greenhouse gas almost 300 times more potent than carbon dioxide in trapping heat. 
• Pesticide Use: Opens in new tabThe large-scale use of pesticides in biofuel crop cultivation pollutes critical habitats and can lead to toxic algal blooms. 
• Hazardous Air Pollutants: Opens in new tabBiofuel manufacturing plants can release high levels of hazardous air pollutants, sometimes comparable to oil refineries, which negatively affect air quality and human health. 
• Ground-level Ozone: Opens in new tabThe production and combustion of biofuels can lead to increased ground-level ozone and smog, which are harmful to respiratory health. 

Water Resources

• Water Consumption: Opens in new tabThe cultivation of many biofuel crops, such as maize and sugar cane, requires significant amounts of water, and large-scale production can strain water resources, particularly in water-scarce regions. 
• Water Quality: Opens in new tabRunoff from fields treated with fertilizers and pesticides pollutes both surface and groundwater. 

Indirect Land Use Change (ILUC) 

• Demand for biofuel crops can drive expansion into new agricultural areas, potentially leading to the conversion of natural or non-food lands for food production or other purposes, creating indirect land use changes and additional environmental impacts.