The chances are that all of you reading this will have eaten or used something today that contains the fruit of the oil palm tree.

Palm oil is in most things such as chocolate, bread, crisps, margarine, soap, cooking oil, detergent, ice cream and lipsticks, and it could even be the bio-diesel in the local bus.

I first came across it in Nigeria 50 years ago where cassava starch was dunked in it to make it easier to swallow, and for frying plantain, but it’s now much more than a subsistence crop grown for local consumption. The oil squeezed from the plum-sized fruit that grows in large bunches, and the finer oil from the kernels, is now the largest single vegetable oil produced globally, at about 30 per cent, ahead of soya, rapeseed, olives and sunflowers.

It dominates world trade, with the majority being used in the US and Europe, and the largest exporter is Malaysia, with Indonesia growing the most. While there are local farmers, most of the major development in the last couple of decades has been by large companies with national support, and the increase has had a serious destructive effect.

Indonesia has doubled its plantation acreage since 2000, and generally in South-East Asia this means clearing five million acres of rainforest each year – the island of Sumatra will have little original forest left within five years. While some of the clearing is for illegal logging, most of it is for palm oil, using heavy machinery to clear and then burn.

This not only means there are fewer trees to take up CO2 but the burning releases much more, particularly as the underground peat often catches fire. Indeed in 1997/98 the smouldering peat produced so much haze that flights in the region were effected and there was a spike in the global annual increase in CO2 in the atmosphere – the only time it has been close to three parts per million, when it is normally around two. Worryingly, many of these peat fires are still going strong, a decade later.

This destruction of the natural vegetation landscape is also a considerable threat to wildlife with orang-utans and Sumatran tigers close to extinction as the natural forest cover disappears.

Neither is it good news for plantation workers, with chemicals, such as European-banned paraquat, being widely used.

Palm oil international trade is poorly regulated and the majority of companies buying it don’t even know where it’s grown. However a small step in the right direction is Unilever’s decision to boycott the largest Indonesian producer because of its record of forest clearance, and perhaps we should follow suit with palm oil bio-diesel.