Guardian: The world needed a climate treaty from the Copenhagen summit last week. All it got was an accord. There was no hiding the disappointment. The deal that emerged after more than a year of pre-summit negotiations and two weeks of face-to-face talks was merely, in Gordon Brown’s terms, "a first step". According to Barack Obama, it was "meaningful". Given the scientific case for urgent action to mitigate the impact of manmade climate change, it was reasonable to expect something …