The world is rapidly depleting its “carbon budget” for the first half of this century, according to a report by economists and climate-change experts, The Guardian reported.

Sea levels are likely to rise by about 1.4 metres globally by 2100 as polar ice melts, according to a major review of climate change in Antarctica, the BBC said.

Fifty years after the signing of the Antarctic Treaty, Brendan Borrell wrote in The New York Times, perhaps it is now time for nations to defend their Antarctic claims.

Groundwater found near the site of the world's worst industrial chemical accident in Bhopal, India, is still toxic and poisoning residents a quarter of a century after a gas leak killed thousands, The Guardian reported two studies as saying.

Governments should not wait for a full Doha Round trade deal before slashing punitive tariffs on wind turbines, solar panels and water-saving showers, Britain’s top trade official told Reuters.

The permanent darkness of the ocean depths is home to a great range of animals, including tubeworms that live off oil seeping from the seabed, Reuters quoted US scientists as saying.

Overfishing of large predatory fish plays a key part in causing algal blooms that block sunlight and strangle marine ecosystems, Nature reported.

Giant otters, monk seals, walruses, spectacled bears, red pandas and fossa are among the carnivores most in need of conserving, according to the most-detailed study yet of the animals, according to the BBC.

Rhino poaching is increasing despite efforts to protect the animals, the BBC cited a report by leading conservation organisations as saying. The global surge in the illegal trade has been driven by demands from Asian medicinal markets, the report concluded.

A study by Chinese and American scientists reveals that female giant pandas use chirp calls to inform male pandas exactly how fertile they are, the BBC said. The discovery suggests that panda vocal signals are more important than previously thought, and will aid in conservation.

Canada – through its support for developing tar sands in Alberta and by abandoning its Kyoto Protocol obligations -- is now the major obstacle to a climate deal in Copenhagen, George Monbiot argued in The Guardian.

A comprehensive food study found greater environmental benefits can be achieved by focusing on improvements to key aspects of production and distribution, according to Science Daily.