Guardian: The head of the UN body charged with leading the fight against climate change has conceded that Barack Obama will face a “revolution” if he commits the US to the deep carbon cuts that scientists and campaigners say are needed. Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change (IPCC), said domestic political constraints made it impossible for the US president to announce ambitious short-term climate targets similar to those set by Europe. And he questioned the …