You can calculate the amount of carbon dioxide emissions from your home or vehicle at http://climatecare.org/. The website also allows you to offset your emissions by supporting projects across the world that are working towards reduce CO2 emissions.
 'Claims for hybrid cars gimmickry'
According to a report in The Times Online edition, road tests carried out by Auto Express magazine found cars promoted as eco-friendly were emitting 56 per cent more carbon dioxide than what was claimed by their manufacturers. The cars included Honda Civic hybrid, Volkswagen’s Polo BlueMotion, which is hailed as Britian's greenest car.
While on the one hand the eco-friendly car market is growing rapidly, this report is expected to make it difficult for consumers to decide which car to really opt for.
See Times Online for full report.