BARCELONA • Despite promises by big companies that produce, trade and use palm oil to clean up their supply chains, complaints still pour in about the conversion of forests into plantations from West Africa to South-east Asia, experts say.

A fledgling effort to balance forest protection and palm oil production aims to ease those tensions by enabling companies to meet growing demand for the cheap, edible oil while ensuring villagers can feed their families, and curbing climate changing emissions from deforestation at the same time.

Led by an independent team of 50 scientists, a draft of the High Carbon Stock Study - commissioned by Asian oil palm growers, agribusiness giant Cargill and consumer goods firm Unilever - was released last month for consultation.

It proposes a new method for evaluating which land could be used for oil palm plantations, taking into account pressure to limit global warming and developing nations' desire to prosper.

"You don't protect the world's forests by coming out with big picture commitments for their own sake. You can only (do it) by giving people who live in and depend on those forests a proper economic stake in that set of decisions," said Mr Jonathon Porritt, chair of the steering committee overseeing the study.

The High Carbon Stock Study is the latest attempt to classify land into different types of forest. It proposes thresholds to determine whether oil palm cultivation should be permitted based on the amount of vegetation and carbon stored above and below ground.

Under this system, land estimated to have 75 tonnes or more of carbon per hectare above ground - equivalent to 100 tonnes of biomass - and 75 tonnes or over in the soil could not be cleared.

This "red zone" would cover peat land, old-growth forests, selectively logged forests and native forests that have grown back for at least 20 years after being cut down, the study says.

In the "green zone", where an oil palm plantation would store more carbon over 25 years than the vegetation now on the land, clearing would be allowed. That is likely to apply to grassland and scrubland.

The more controversial "amber" area lies in between.

It is in this area that tough decisions would have to be made in balancing projected carbon emissions from cutting down forest and the potential boost to local livelihoods from the palm oil industry.

The type of land expected to fall into this band would be young regenerating forest and other types of degraded forest.

REUTERS