Biofuels are widely considered one of the most promising sources of

renewable energy by policy makers and environmentalists alike. However,

unless principles and standards for production are developed and

implemented, certain biofuels will cause severe environmental impacts

and reduce biodiversity – the very opposite of what is desired.

Corn-based ethanol is currently the most widely used biofuel in the

United States, but it is also the most environmentally damaging among

crop-based energy sources. A new article qualitatively contrasts major

potential sources of biofuels, including corn, grasses, fast-growing

trees and oil crops. The study highlights their relative impacts on the

environment in terms of water and fertilizer use and other criteria to

calculate the environmental footprint of each crop.

“The central goals of any biofuel policy must minimize risks to

biodiversity and to our climate,” says lead author Martha Groom of the

University of Washington. She recommends the further use of algae and

fast-growing trees as biofuel sources because they yield more fuel per

acre than any feedstocks currently being pursued.

As well as comparing potential biofuel feedstocks, the study also

recommends a number of major principles for governing the development

of environmentally friendly biofuels. Feedstocks should be grown

according to sustainable and environmentally safe agricultural

practices with minimal ecological footprints (the area of land required

to grow and support sufficient amounts of the crop). In particular,

emphasis should be placed on biofuels that can sequester carbon or have

a negative or zero carbon balance.

“While some biofuels may be an improvement over traditional fuels,

we believe we should focus much more on the biofuels of the future that

can be developed in small spaces, rather than extensively on crop

lands,” explains Groom. “We also must shun biofuels that are grown by

clearing biologically-rich habitats, such as tropical rainforests, as

has occurred with oil palm and some other biofuels.” The study was

co-authored by Elizabeth Gray, the director of science for The Nature

Conservancy’s Washington state program, and Patricia Townsend, a Ph.D.

candidate in the Department of Biology at UW.

This study is published in Conservation Biology.

Source : Wiley-Blackwell