Biodiversity and fossil fuel extraction

The other legacy of our energy consumption

There’s a global biodiversity crisis unravelling before our eyes and most of the major threats to biodiversity (such as habitat loss and invasive species) are being exacerbated by the growing impact of climate change. Science has convincingly demonstrated the connection between the burning of fossil fuels and climate change. Less well understood is the impact on our natural world of the actual extraction of these fossil fuels – coal, oil and gas.

A growing footprint

The process of extracting fossil fuels, which includes drilling and all forms of mining, has traditionally been seen as a temporary and spatially limited disturbance to an ecological system. In many cases it is assumed that some kind of restoration activity, often legally mandated, will return the ecosystem to a state close to its pre-disturbance state. Because of this, extraction activities have been considered trivial disruptors of natural systems in comparison with other human activities (such as agriculture). Indeed, in many countries extraction areas are considered ‘borrowed’ rather than ‘consumed’.

The assumption of a relatively small disturbance footprint (for example, less than 0.05% of the land surface of Australia is disturbed by mining and mineral processing) has meant that it was previously easy to dismiss the environmental impacts of extraction as unimportant at larger scales. But should it be dismissed? In reality, ecosystem disturbance and degradation, as a direct or indirect result of extraction, has an increasingly large spatial footprint.

In order to meet demand driven by growth in incomes, consumption of goods and industrial development in major emerging markets, fossil fuel consumption is projected to increase dramatically by 2035: oil demand by more than 30%, and natural gas and coal demand by around 50%. As the most easily accessed reserves are depleted, attention is shifting to new areas and methods, such as coal seam gas and shale oil extracted by fracking. This threatens regions that are currently undeveloped and often highly biodiverse.

“We identified two key areas most at risk from future fossil fuel development: northern South America (the Amazon Basin) and the western Pacific Ocean (the Coral Triangle).”


Figure 1: Overlap between fossil fuel reserves and species richness (top panel) and threatened species (bottom panel). The two highest risk areas are circled. (Modified from Butt et al., 2013)

 Direct and indirect impacts

The direct impacts of fossil fuel extraction on biodiversity include the degradation of habitat at the local-scale, species loss, disturbance, fragmentation and edge effects; all of which can compromise ecosystem function at larger scales. The indirect effects of extraction, however, can have even more profound, large-scale impacts on biodiversity. The infrastructure required to support extraction (roads, airports, power lines, towns) facilitates further human development and a resulting cascade of impacts including land clearing, species invasions, and the illegal harvesting of wildlife. The third category of impact is the consequences of disasters (eg, catastrophic oil spills).

So, given the distribution of known fossil fuel reserves and biodiversity, are there any areas that raise particular concern? We mapped the spatial overlap between areas of high marine and terrestrial biodiversity and reserves of fossil fuel. We also compared where high numbers of threatened species were in relation to reserves of fossil fuels (Figure 1). Based on this analysis, we identified two key areas most at risk from future fossil fuel development: northern South America (the Amazon Basin) and the western Pacific Ocean (the Coral Triangle).

Critical areas

The Amazon Basin, which covers eight countries in South America (Colombia, Peru, Ecuador, Bolivia, Venezuela, Suriname, French Guiana and Guyana) contains 10% of the world’s biodiversity and over 50% of its tropical forest. The Coral Triangle of Southeast Asia is the most biodiverse marine area of the world, containing two-thirds of the world’s coral species and one-third of the world’s species of fish (see box).

We also analysed the relationship between petroleum reserves and terrestrial species richness (Figure 2). This revealed four broad quadrants of threat level. Regions in the upper right of the figure (red) represent large reserves and high levels of biodiversity. These are areas of particular concern and included in this quadrant are Bolivia, Venezuela and Borneo.

Ecoregions such as North Burma, Senegal and Ecuador have medium-to-high species richness but are in areas of small petroleum reserves, so we would expect the pressure on biodiversity from fossil fuel extraction to be low. Regions with large petroleum deposits but low species richness (purple) are expected to experience habitat degradation and associated processes, but the net impact on biodiversity will be relatively small.

An international responsibility

There is an additional worry relating to these regions of concern. Many of the countries with high biodiversity where fossil fuel extraction is expanding suffer from poor regulation and enforcement. They also lack the ability to respond effectively to environmental disasters that are too frequently connected to the extraction of fossil fuels. Such regions may also be too remote to attract media coverage and thus environmental damage caused in these areas may remain undetected and unaddressed.

Figure 2: Petroleum reserves and species richness, by ecoregion. (From Butt et al., 2013)

Figure 2: Petroleum reserves and species richness, by ecoregion. (From Butt et al., 2013)

It is essential that fossil fuel extraction in these regions takes place according to best practices, including rigorous environmental monitoring to ensure that damage is minimized. Recognition of the direct and indirect threats to biodiversity from fossil fuel extraction in these regions is essential in the establishment of suitable norms and processes which can guide controlled development so that environmental damage is minimised.

International environmental organisations could fulfil an essential role by ensuring that fossil fuel extraction takes place according to best practices and ideally avoids areas of high biodiversity. It is crucial that trade-offs between biodiversity conservation and development are properly assessed to ensure threatened or endemic species are not lost.

International pressure can also help to ensure that any environmental damage that does occur is mitigated and the companies involved are appropriately penalised, as in the case of BP and the Deepwater Horizon disaster.

One possible mechanism to preserve biodiversity in fossil fuel-rich areas was recently attempted at Yasuní National Park in Ecuador. This highly biodiverse area also has the country’s largest oil reserves. In 2007 the Ecuadorean government proposed that in return for not extracting the oil from the park, and keeping the forest biodiversity, they would be compensated. The funds were to be raised through the international Green Climate Fund (UNFCCC), to the value of $3.6 billion, about half the value of the oil.

Ten per cent of the money was raised, from countries, regions, corporations, foundations and individuals, to be invested in renewable energy projects. Unfortunately, due to lack of global commitment, the project failed. Oil extraction will now go ahead. With strong international support, schemes such as this could be a way of protecting biodiversity in fossil fuel rich areas.

More info: Nathalie Butt


Butt N, HL Beyer, JR Bennett, D Biggs, R Maggini, M Mills, AR Renwick, LM Seabrook &HP Possingham (2013). Biodiversity Risks from Fossil Fuel Extraction. Science. 342: 425-426.

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