Glaciers in the Andes have shrunk by up to 50 per cent since the 1970s, and some could disappear altogether, a study warns.

Thousands of supporters of Hugo Chavez rallied outside his presidential palace in Caracas today in an alternative inauguration for a leader too ill to return home for the real thing.

A third of the Earth's land surface is classified as desert, from the McMurdo Dry Valleys of Antarctica to the North African Sahara – and it is a subject that represents a life's passion for landscape photographer George Steinmetz. Inspired by a hitchhiking trip across North Africa in the 1970s, the American aerial artist has spent the past 15 years documenting deserts from above.

Mexican President Felipe Calderon is clearly a fan of lexical clarity – last week, he put a motion to congress to change his country's name from the United Mexican States to, simply, Mexico. It would put Mexicans in a select group of countries without the need to point out that they're an Independent Democratic Republic of Whatever (well done, Canada, Malaysia, Georgia and others).

The trail

Jordi Ruiz Cirera, 28, has won the Taylor Wessing Photographic Portrait Prize 2012 for his photograph of Bolivian woman who (only reluctantly) agreed to have her portrait taken. 

Argentina's world class forwards were instrumental in a 2-1 away win over Chile last night that gave the visitors a three-point lead in the standings as the South American World Cup qualifying campaign takes a break until March.

Stopping Lionel Messi is the primary concern of South American teams facing Argentina in the World Cup qualifiers. This week it is Uruguay's turn.

On the eve of the Rio+20 conference, the world’s 105 science academies have warned international leaders that a failure to act now on population growth and over-consumption will have “potentially catastrophic implications for human wellbeing”.

In the Cordillera Real range in Bolivia he came down some slopes by bicycle

It's best not to mess with Theresa May. There was a sharp edge to the Home Secretary's exchange with Ken Clarke as they accepted the Spectator Parliamentary award for Double Act of the Year.

Bolivia's Salar de Uyuni is the world's largest salt flat, a landscape so bright, you've got to wear shades. Graeme Green gets an eyeful

Cheering crowds greeted more than 1,000 indigenous protesters as they entered Bolivia's capital, La Paz, after a two-month march from the Amazon lowlands.