Ecologists protested at the US embassy in London Feb. 12 over President Bush's refusal to join the Kyoto agreement to cut greenhouse gases and tackle climate change. The long-stalled treaty goes into effect this week, committing 136 countries to reduce gas emissions by 5.2 percent below 1990 levels in the next decade. Prime Minister Tony Blair has declared climate change "the biggest, long-term challenge the global community faces". But the US, the biggest producer of greenhouse gases by far, is the only major industrial country not to have signed.