Independent: A promised tax on plastic bags, a pledge to make all new buildings zero-carbon, higher charges for flights, a crackdown on new gas-guzzling cars and a handout to less thirsty ones – Alistair Darling’s budget contained a number of conspicuous green measures yesterday, but they were not enough to satisfy environmental campaigners. The essence of their charge was that while the new moves were welcome, the Chancellor was tinkering at the margins of environmental problems, and the …