Palm oil comes, not from regular palm trees, but from the 'oil palm' - this tree grew originally in Africa, but is now being farmed in Asia very successfully. So successfully that native rainforest is routinely being cleared by burning in order to grow more oil palms.
Palm oil is cheap and versatile, it transports well and is just-spreadable at room temperature. The yield from just one oil palm is impressive. If oil palms were replaced with another oil-producing crop, even more land would need to be cleared to produce the same output.
The palm oil industry has grown too quickly - palm oil is in practically every convenience food item and every convenience beauty item that you can think of. Unsustainable farming methods are rife - clearing vast areas of fragile, ancient rainforest by burning, means trees and animals are wiped out. Heartbreaking images of orphaned orangutans are just the tip of the problem. This banned Christmas advert by Iceland supermarket (in collaboration with the charity Greenpeace) explains the problem visually in a family-friendly thought-provoking cartoon.
Please check your regularly-purchased items for palm oil. Sometimes you can avoid it completely -Meridian' peanut butter, 'Pip & Nut' peanut butter (the kids' favourite) and 'Whole Earth' (my favourite) are all palm oil free and come in 1kg bulk tubs. The only digestive biscuits without palm oil that I could find (or rather, that my friend tracked down for me) are 'McVities Digestives Lights'. It's also worth knowing that 'McVities Rich Tea Classic Biscuits' are palm oil free. On the biscuit topic, Bahlsen Choco Leibniz biscuits (dark and milk) happen to be palm oil free - yum! Most recently I was very pleased to discover that ASDA's own brand oatcakes are made without palm oil (I have been looking for palm-oil-free oatcakes for months and months...)
Lots of chocolate bars do contain palm oil, so please check that any you buy are labelled as containing 'sustainable palm oil' - this certification by RSPO (Roundtable on Sustainable Palm Oil) should indicate transparent supply chains and no clearing of previously-untouched forest, plus a certain standard of workers' rights. It's good to know that 'Green & Blacks' and 'Divine' chocolate brands are palm oil free.
To save yourself from trawling the supermarket shelves, have a look at the fantastic Ethical Consumer website's page listing palm-oil-free products.
Once you start checking for palm oil, you begin to realise how much processed stuff (containing goodness knows what) has crept into daily life. Go and have a look in your cupboards now and see if there are any swaps you could make next time you shop...