Martin Roberts, PlanetArk 20 May 10;
A large but limited amount of land can be used to provide plant-based fuel without cutting the world's food supply, environmentalists and consultants told a global biofuels gathering on Wednesday.
Governments around the world have promoted biofuels in order to cut greenhouse emissions and their dependence on fossil fuels, as well as prevent pollution.
"In climate change, in oil spills, the Earth is paying the price for providing us with all this easy, unsustainable oil," Margo Oge of the United States Environmental Protection Agency told the World Biofuels conference in Seville.
Public debate, however, has focused on whether grain used to make fuel is needed to combat world hunger. Biofuels makers have often replied that they use up just 3 percent of the global grain supply.
Martina Fleckenstein of the World Wild Fund for Nature said the WWF estimated 380-450 million hectares could be sustainably planted for fuel feedstocks, alongside 1.6 billion ha needed to guarantee the world's food supply.
Carlo Hamelinck of consultants Ecofys provided a similar estimate of 480 million ha, which could provide enough biofuel to make the world's energy mix sustainable by 2045.
"It is large, but not shocking. It can make a large contribution to the global energy supply," he said in the southwestern Spanish city.
Estimates on how much of the world's energy supply could be met by biofuels varied widely.
Hamelinck predicted 50 percent, while Enrique Cerda, a professor of genetics at Seville University, said data from the United Nations Food and Agriculture Organization showed biofuels could only provide 3 percent of the total energy supply.
Hamelinck urged biofuel manufacturers to use raw materials grown with sustainable water supplies, and without eroding soil or using land needed to maintain biodiversity.
"In the coming years we will see if the industry is serious about sustainability," he said. "It is up to you to demand feedstocks which are sustainable."
Supporters of biofuels say growing crops for fuel can provide much-needed cash flows to small farmers in developing countries.
Tanzania could plant sugar cane, jatropha, sweet sorghum and palm oil to make biofuel, Energy Minister William Mganga Ngeleja said, but the southern African country cultivated less than 10 percent of its arable land.
"The exact amount of land used will depend on investment flows, but this gives you some idea of the potential.
"I would like to take this opportunity to entice and welcome investors in biofuels to come and invest in Tanzania," he said.
(Reporting by Martin Roberts)
