Press Association: A Nobel Prize-winning scientist has warned that switching from fossil fuels to biofuels could do the planet more harm than good. Prof Paul Crutzen calculated the global warming effects of the fertiliser needed to grow energy crops like biodiesel and bioethanol were much worse than has been estimated. He believes a larger proportion than thought of the nitrogen in fertilisers is converted into nitrous oxide, a potent greenhouse gas, New Scientist magazine reported. The …