News roundup: Carbon offsetting criticised, green muscle cars and more
When trees aren't green: carbon offsetting debate rages again as scientists condemn treeplanting schemes [Guardian]
New bio-ethanol Hummer proves that green cars are not for wimps [CNET]
California is blazing a trail in the fight against climate change, with Schwarzenegger hailed as unlikely green hero [Independent]
Planting and preserving more rainforests could slow global warming [Science Daily]
Live Earth lineup announced: Madonna to headline London gig with Beastie Boys, Bloc Party and more
