POZNAN, Poland Clearing tropical forests to plant biofuels is a bad idea for the climate and reduces the diversity of animal and plant life, a study found on Monday.
"Keeping tropical rain forests intact is a better way to combat climate change than replacing them with biofuel plantations," according to scientists from seven nations writing in the journal Conservation Biology.
Millions of hectares of forest land in South East Asia has been converted to palm oil plantations to produce biofuels -- seen as greener than fossil fuels because plants soak up greenhouse gases from the atmosphere as they grow.
But the study, released on the opening day of 187-nation talks on a new U.N. climate treaty in Poland, said it would take 75 years for carbon emissions saved from using biofuels to make up for carbon released into the atmosphere by burning down a forest to clear it for a biofuel plantation.
And the balance would only be achieved after more than 600 years if the habitat was carbon-rich peatland, it said. Planting biofuels on degraded grasslands, however, could lead to a net removal of carbon after only a decade.
"Sourcing biofuel feedstock from crops such as palm oil simply doesn't make environmental sense," said Emily Fitzherbert from the University of East Anglia, England, who was one of the authors.
The spread of biofuel plantations in Asia has also led to a loss of habitat for species such as rhinos and orangutans according to the report, by scientists in the Netherlands, the United States, Malaysia, Germany, Indonesia, Britain and Denmark.
"Subsidies to purchase tropical biofuels are given by countries in Europe and North America supposedly to reduce their greenhouse gas emissions from transport," said lead author Finn Danielsen of Denmark's Nordic Agency for Development and Ecology.
The scientists said that plants thriving alongside palm oil in plantations were usually ones that liked bright sunshine while forest species such as lianas, orchids and native palms and others that favored shade died out.
They said that only one in six forest animal species could survive in plantations.
The authors called for the development of common global standards for sustainable production of biofuels. And they said the problems were not just in South East Asia.
"In Latin America, forests are being cleared for soy production which is even less efficient at biofuel production compared to oil palm," said co-author Faizal Parish of the Global Environment Center.
He said that reducing deforestation was a far better way for countries to fight climate change while also meeting their obligations to protect biodiversity.
-- For Reuters latest environment blogs click on: blogs.reuters.com/environment/
(Editing by Mark Trevelyan)