Mexican telecom giant Carlos Slim has topped Forbes magazine's billionaire's list - the first time since 1994 that an American has not led the rankings.

Mr Slim's fortune rose by $18.5bn (£12.4bn) from last year to $53.5bn.

That beat Microsoft founder Bill Gates into second place, with US investor Warren Buffet in third.

After a tough year in 2009,

The Italian government has signed a deal with Google to put the contents of two national libraries on the internet.

Up to one million antiquarian books - including works by Dante, Machiavelli and Galileo - will be scanned and made available free on Google Books.

There is no copyright issue as all the works were published before 1868.

The Italian

UN Secretary-General Ban Ki-moon has asked the world's science academies to review work of the Intergovernmental Panel on Climate Change (IPCC).

Work will be co-ordinated by the Inter-Academy Council, which brings together bodies such as the UK's Royal Society.

The IPCC has been under pressure over small errors in its last major assessment of climate science in 2007.

Mr Ban said the overall concept of man-made climate change was robust, and action to curb emissions badly needed.

The Inter-Academy Council will convene a panel of experts to conduct the review.