Counting the environmental and social costs of the ‘green petrol’ expansion drive

At a superficial level, lower-carbon fuels made from renewable crops make much more sense than burning non-renewable fossil fuels.

But does it make sense to set aside ever larger chunks of farmland — and even parts of the sea — to growing plant-based petrol? Already, a substantial area of scarce farming land has been devoted to growing a variety of crops that are destined to fuel cars, planes and ships with biologically-derived fuels.

Next month, at the 30th meeting of the UN Framework Convention on Climate Change (COP30), Brazil will ask world leaders to support a global project to quadruple production of “sustainable fuels”, such as biofuels, hydrogen and biogases.

The focus of early “first-generation” biofuels was on oily or sugar-rich crops such as canola, soya, sugar cane or maize, but this soon raised concerns about the impacts on global food security and food prices as commercial farmers were lured into growing plant “petrol” and biodiesel rather than food.

Since then, there has been a push to develop second, third, fourth and fifth-generation biofuels from a wider variety of biological sources (see box further below), including genetically modified algae or hemp (dagga).

Yet despite enjoying government energy subsidies and tax incentives in several nations, the International Energy Agency notes that biofuel growth is running at less than half of what is needed to achieve net zero emissions by 2050.

The International Air Transport Association is also suggesting that the aviation industry will probably have to maintain its reliance on crop-based biofuels for the immediate future, until more sustainable fuels are developed.

What does this all mean for human food production, water, the soil or wildlife? Are quick-fix solutions to the climate change crisis creating a new set of social and environmental problems?

A recent study commissioned by the Brussels-based Transport and Environment (T & E) lobby group estimates that biofuel crops already take up 32 million hectares of land — roughly the size of Italy — to meet just 4% of global transport energy demand.

By 2030, this is projected to expand to 52 million hectares, equivalent to the size of France.

T&E claims that the same land could feed 1.3 billion people, while using just 3% of that area for solar panels would produce the same amount of energy.

The organisation argues that electric vehicles are more efficient than conventional fossil fuel cars, so solar energy could power close to a third of the world's current car fleet if those vehicles were electric.

The report, produced by the Cerulogy consultancy, indicates that the biggest suppliers of biofuel feedstock are the United States (mainly maize), Brazil (mainly sugar cane) and the European Union.

Yet, according to Cerulogy, biofuel production causes 16% more CO2 emissions than the fossil fuels it aims to replace. This estimate is based on the indirect impacts of farming and deforestation for biofuel crops, which release stored carbon.

A separate scientific review, by Prangon Chowdhury and colleagues, acknowledges that biofuels hold “immense potential”  to address global energy demands while mitigating climate change.

However, the Bangladesh-based researchers conclude that current biofuel policies still present a wide range of significant environmental, social and economic challenges.

These fuels were often viewed as more environmentally friendly than fossil fuels, mainly because they are regarded as carbon–neutral and free from fossil fuel inputs. However, the production of biofuels still consumes significant fossil energy during ploughing, fertilising and harvesting.

Food security, nutrition and health

The Chowdhury review cites several studies that raise critical concerns around the “food-versus-fuel” debate. They note that in Indonesia, palm oil plantations have displaced subsistence farming, undermining local food systems and increasing dependence on volatile global markets.

In other developing countries, economic incentives for biofuel cultivation often drive the conversion of natural areas into croplands, further exacerbating food insecurity and habitat loss.

This competition between food and fuel production has raised concerns about its implications for undernutrition, especially in low-income populations. However, some studies suggested that biofuel production occupies only around 2 % of global cropland, and even if this figure doubled or tripled, global food shortages are unlikely.

Chowdhury suggests that the issue is less about absolute food supply and more about food distribution, which is heavily influenced by food prices. Biofuel demand has been shown to contribute to food price inflation, particularly for staple crops like maize.

Land displacement and loss of livelihoods

A significant concern with large-scale biofuel plantations is the displacement of communities, particularly in developing countries where ambiguous land ownership leaves rural populations vulnerable.

Without formal land titles, many face dispossession and inadequate compensation.

Companies like Brasil Biofuels and Agropalma have been accused of illegal land grabbing and forced evictions in Brazil’s Pará province, with Quilombola (descendants of African slaves), riverine and campesino communities in the Amazon bearing the brunt of these practices.

In Rwanda, swamplands once used by local communities for fishing, grazing and occasional cultivation were converted into biofuel plantations. This shift sparked a conflict between local informal land rights and the government’s development plan, as the swampland — making up 10% of Rwanda’s land-scarce area — was designated as state property. As a result, the local community lost access to the land following a concession granted to the biofuel company, displacing populations and disrupting their livelihoods.

While the biofuel industry promised new rural jobs, Chowdhury says the reality often falls short of this promise.

“Many of these jobs are seasonal, low-paying and exploitative, perpetuating labour inequities. Large agribusinesses and plantation owners typically capture the majority of profits, while smallholders and rural labourers receive only a fraction.”

Environmental impacts

Growing more biofuels typically leads to the clearance of more land, causing deforestation, biodiversity loss and habitat destruction.

When forests are cleared to plant biofuel crops like sugarcane or palm oil, the direct consequences include the loss of living space for numerous wildlife species and the degradation of local ecosystems.

Often, there are secondary effects when land previously used for growing food is converted to biofuels. This displacement causes food production to shift to other areas, potentially leading to the conversion of additional natural habitats into agricultural land elsewhere. Alternatively, if farmers switch from growing food crops to biofuel crops due to higher market prices for biofuels, this can increase pressure on land resources and cause further deforestation as farmers seek to maintain food production levels.

One prominent example is Brazil, where the rapid development of sugarcane has contributed to deforestation and habitat loss and the expansion of cattle ranching deeper into the Amazon forest.

In Southeast Asia, especially in Indonesia and Malaysia, government incentives for growing palm oil have also led to conflicts with local communities and indigenous peoples who rely on these forests for their livelihoods.

Apart from the loss of wildlife habitat and subsequent biodiversity decline, land is converted into monocrop (single species plants), which further reduces habitat for wildlife, including fungi, beetles, birds and other crucial pollinator species.

Marine and freshwater impacts

Water use in biofuel production varies significantly, with several crops using high volumes in water-scarce areas such as Portugal and Spain.

Algal biofuels produced in some open pond systems in Hawaii use over 20 times more water than closed algal bioreactor systems in the Netherlands.

Marine and freshwater ecosystems are also at risk from biofuel production, particularly through the cultivation of microalgae, which is linked to eutrophication. This process leads to harmful algal blooms when sunlight penetration is reduced, along with lower oxygen levels and toxic bacteria that kill fish and other water species.

Invasive algal species from cultivation sites can also spread into coastal ecosystems such as mudflats, mangroves and coral reefs. Genetically modified biofuel species have raised particular concern because of their potential to invade and disrupt native ecosystems.

Biofuel production can also lead to contamination of water with nitrate fertilisers or increased water extraction from local groundwater wells during irrigation.

Chowdhury notes that agriculture already uses about 70 % of all freshwater extracted globally. As a result, water resources for agriculture are becoming increasingly strained due to growing competition from residential and industrial uses.

“Producing ethanol from corn consumes about 170 litres of water per litre of ethanol, while biodiesel from soybeans requires roughly 900 litres per litre of biodiesel.”

Soil degradation

One of the main worries is around the intensive farming of corn and soybeans, leading to erosion of topsoil and nutrients by water and wind. Moreover, removing crop residues such as mealie stalks for biofuel production further exposes the soil, diminishing its organic carbon levels, structure and erosion resistance.

• South Africa’s Biofuels Regulatory Framework, published in 2020, recognises that first-generation (crop-based) biofuels can be a risk to food security if commercial farmers switch from food to biofuels feedstock production. It also recommends that, as a water-scarce nation, farmers should prioritise rain-fed biofuel crops. The cultivation of oil-rich Jatropha is banned due to biodiversity concerns and to protect local bird and animal species from poisoning, since Jatropha is an alien plant with toxic leaves and pods. DM