Polar bears have been around for millions of years longer than previously thought – and might be resilient to current climate change and habitat loss.

As US crops wither in drought, researchers are turning to symbiotic fungi to help crops survive extreme conditions without resorting to genetic engineering

It created a media feeding frenzy and dragged climate scientists' reputations through the mud, but nobody will be prosecuted for the "climategate" email hack. Thousands of emails were stolen from the servers of the Climatic Research Unit (CRU) at the University of East Anglia in November 2009 and posted on a Russian email server. Climate sceptics seized on them to claim that scientists had conspired to withhold or alter data, unfairly manipulated the peer-review process and smeared their critics.

A new crop of weight-loss drugs is expected to reach the clinics this year and the next, but will their side effects be hard to swallow?.

It's chemistry's greatest challenge – inventing systems that turn water and sunshine efficiently into cheap, clean energy for all.

It's time for evolution to take centre stage in the practice of medicine, says the world's first "Darwinian paediatrician" Paul Turke.

Controlling smog and soot is the classic win-win situation, so it's great that the world is finally waking up to the idea, says Drew Shindell.

Women living in an illegally polluted region of Italy are more likely to have birth defects, possibly due to accelerated ageing of their cells.

The launch of the UK Biobank, the world's largest medical database, will reveal the effects of genes and environment on health.

Oil giant Shell last week overcame the last major legal obstacle to its plans in the Arctic Ocean this summer. On Wednesday, the US Department of the Interior (DoI) approved the firm's oil spill response plan, effectively granting permission for exploratory drilling in the Beaufort Sea, north of Alaska.