'Climate change making Everest more dangerous'
Climate change is making Mount Everest more dangerous to climb, a Nepalese Sherpa said in Kathmandu after breaking his own record by making a 20th ascent of the world's highest peak.
The most pressing scientific question and political challenge about global warming at present is this: can we avoid 'dangerous' global warming, and prevent it reaching levels beyond which it will become irreversible?