The study compared total life-cycle emissions from biofuels from various sources with diesel. Fuel from canola has 49% lower emissions over its life cycle than diesel and, for a waste product such as used cooking oil, emissions can be 87% lower than diesel.
However, total life-cycle emissions from biofuels derived from palm oil plantations established by clearing rainforest or swamp forest are up to 21 times higher than diesel.
The problem is that some biofuels do indeed come from these sources.
The CSIRO report points to other studies that have estimated that a substantial proportion of international palm oil production is established by clearing - and often burning - these forests in Indonesia and Malaysia, which together supply 83% of the world's palm oil:
- It has been estimated that in Malaysia nearly half of all new oil palm plantations involve deforestation, with 87% of deforestation between 1985 and 2000 due to oil palm expansion.
- From 1982 to 1999, about 16,000 square miles of Indonesian tropical rainforest was converted to plantation. Oil palm plantations were responsible for at least 44 percent of that rainforest loss.
And although palm oil hasn't so far been a major source of biofuels, that may slowly change:
with growing demand for biodiesel, especially in Europe, with increasingly large suggested as well as mandatory targets, it has been observed that it is unlikely production will be able to meet future demand without the use of palm oil as a feedstock.
It seems that biofuels do have the capacity to lower greenhouse emissions from transport. But whether their contribution will be good, bad or ugly depends critically on where they come from.It's true: oils ain't oils.