From an economic policy perspective, an important distinction between biofuels and fossil fuels is that only the former is sustainable or renewable.
Whereas we can continue to obtain energy from biofuels indefinitely in principle, the Earth's reserves of fossil fuels was determined millions of years ago[3] and is therefore fixed as far as our foreseeable future is concerned.
The great variability in the ease of extraction of fossil fuels however makes its endgame scenario one of increasing prices over one or more centuries rather than of abrupt exhaustion.
[4] From the perspective of climate and ecology, biofuels and fossil fuels have in common that they contribute to the production of atmospheric carbon dioxide, which has emerged in recent decades as the fastest-changing greenhouse gas, whose principal impacts are global warming and ocean acidification.
Burning of both fossil fuels and biofuels usually also produces carbon monoxide, which is toxic and can kill a person after mixing with the haemoglobin of the blood, increasing its concentration in the body.