An international coalition has appealed to former US vice-president and environmental campaigner Al Gore to take up their concerns about the world's rapidly developing biofuels industry.
They have told him that large-scale biofuel production and new incentives to promote biofuels, based on "energy-crop monocultures", are having a devastating impact on biodiversity and contributing to global climate change.
South Africa is in the process of developing a draft biofuel strategy, but it has run into strong criticism from environmental groups.
The coalition asked Gore to consider their concerns before addressing the World Biofuels Markets Congress in Brussels this week and speaking at the First Biofuels Congress of the Americas in Argentina in May.
The coalition said one of their major concerns was that energy crop monocultures threatened the global climate.
"Energy yields are highest from crops growing in the tropics; hence much of the global biofuel demand is being, and will continue to be, met from Asia, Latin America and Africa.
"Already, biofuels production is leading to increased rates of deforestation in many rain forest nations, including Indonesia, Malaysia, Colombia, Brazil, Paraguay, Argentina and Cameroon."
For example, Indonesia planned to expand palm oil production for biofuels 43-fold, a move that threatened most of that country's remaining rain forests and peat lands.
Indonesia is the world's second-most biologically diverse country, after Brazil. South Africa ranks third.
"If those plans are implemented, up to 50 billion tonnes of carbon are likely to be released into the atmosphere - the equivalent of over six years of global fossil fuel burning, that would clearly stand in the way of our common objective of stabilising the climate before feedback mechanisms make this impossible."
Nasa had shown that the rate of Amazon deforestation correlated directly with the increasing world market price of soya, the coalition said. "That price is expected to rise sharply as demand for soya biodiesel grows."
The coalition also told Gore that many organisations, particularly from the global south, had signed declarations expressing concerns about the threats posed by biofuel monocultures, including threats to food security, human and land rights, and biodiversity.
"Recently the poor in Mexico have seen the price of corn - their staple food - rise by nearly 70% in six months, leading to civil unrest because of US ethanol production."
South African environmental groups have expressed similar concerns about the rising price of maize locally. Both agricultural expansion and a shift to more intensive agriculture - much of it for GM (genetically modified) crops - would be devastating for biodiversity, the coalition warned.
"The millennium ecosystem report has shown that 60% of ecosystems are already degraded.
"An expansion of biofuel monocultures will lead to more habitat loss, more pollution and more alien invasive plants," it said.