Cleaning up cars: do biofuels, electricity or hydrogen represent the best bet for the environment?

摘要

There are countless voices clamouring for public attention ahead of the UN Climate Change Conference in Copenhagen this December. The risks posed by climate change are now widely accepted, but the array of options for cutting greenhouses gases isrnmind-boggling. One thing is clear: cutting CO_2rnemissions from cars will have to play a large part in the process. Globally, transportation contributes one-quarter of all greenhouse gas emissions, with 80% of that coming from road transport and half of that from cars. Furthermore, total CO_2 emissions from cars will double by 2050 unless alternatives to fossil fuels are developed.