Paul Holland of the British Antarctic Survey (BAS) stuck to his findings last year that a shift in winds linked to climate change was blowing ice away from the coast, allowing exposed water in some areas to freeze and make yet more ice.

BBC: Melt may explain Antarctica's sea ice expansion

Last August Mr Ayling spelled out his intention to shift his focus gradually from cut-price leisure travellers to the premium passengers from whom airlines make money.

ECONOMIST: British Airways

Mr Mohamud said there had been a paradigm shift in Somalia since his government took office last year.

BBC: Somali conflict: Mohamud and Cameron hail 'new era'

President Bush delivered his last State of the Union address to Congress Monday night, a speech dominated by his description of a policy shift that he said had brought success and the promise of victory in Iraq.

NPR: Fact-Checking the State of the Union

According to Mr Tyrie, this marks a shift of opinion inside his own party: when he published a pamphlet last year suggesting that the upper chamber should be directly elected, virtually no Conservatives agreed.

ECONOMIST: Lords reform

President Obama began to stress America's 'strategic shift' towards Asia late last year, and he reiterated it in his State of the Union address.

BBC: Barack Obama confronts the China challenge

On 12 October 2010, the shadow chancellor, making his first Commons appearance since being appointed by new Labour leader Ed Miliband last week, challenged Mr Osborne on whether there had been any shift in his plans to eliminate the deficit by 2015.

BBC: Johnson critices Osborne in first Commons clash