Nuts picked from Amazon rainforests helped fuel the world's first commercial airline flight powered by renewable energy on Sunday. A Virgin Atlantic jumbo jet flew from London to Amsterdam with one of its fuel tanks filled with a bio-jet blend including babassu oil and coconut oil.

Biofuels, which are currently mainly produced from crops such as grain, vegetable oils and sugar, are seen by advocates as a way to cut emissions of greenhouse gases and reduce dependence on fossil fuels. There has been concern, however, that an expansion in the area of crops grown for energy has helped drive up food prices, and some scientists have questioned the environmental benefits of so-called first generation biofuels.