In what was described as a watershed moment, more than 2,500 leading environmental experts agreed a statement that called on governments to act before the planet becomes an unrecognisable – and, in places, impossible – place to live.
At an emergency climate summit in Copenhagen, scientists agreed that "worst case" scenarios were already becoming reality and that, unless drastic action was taken soon, "dangerous climate change" was imminent.
In a strongly worded message that, unusually for academics, appealed directly to politicians, they said there was "no excuse for inaction" and that "weak and "ineffective" governments must stand up to big business and "vested interests".
Steps should be "vigorously and widely implemented", they said, to reduce greenhouse gases. Failure to do so would result in "significant risk" of "irreversible climatic shifts", the statement added.