The US President's 'wide-ranging' State of the Union address sets out a bold vision for his second term
President makes gay rights paramount as many welcome surprisingly liberal second-term agenda
Four challenges for Obama when he returns to the Oval Office after today's inauguration celebrations
Scientists hope 2012's record-breaking heat will drive climate change onto the political agenda
New York mayor Michael Bloomberg throws his weight behind the President. Will it make a difference?
Heathrow unguarded, a climate change sceptic at Environment and a green belt sceptic at Planning
Nearly all of Greenland's ice sheet began to melt for a few days in July. Is climate change to blame?
Petermann Glacier calves a second iceberg in two years, raising concerns at the rapid pace of ice loss
Opinion digest: David Cameron and Tory re-branding, a tip for England at Euro 2012 and Europe's impending dark age
Lord Smith gives guarded support for fracking as he tackles government over green issues