The US EPA will declare carbon dioxide a dangerous pollutant within “the next few months”, allowing emissions to be regulated under the Clean Air Act regardless of whether the US Congress passes the current climate change legislation.
A UK Royal Society study has concluded that many engineering proposals to reduce the impact of climate change are "technically possible". But they also stressed that the potential of geo-engineering should not divert governments away from their efforts to reduce carbon emissions.
Space-based solar arrays transmitting power back to Earth are now technically feasible – but very expensive. However private companies are already beginning to design prototypes, moving the concept out of the realm of science fiction.
UN Secretary-General Ban Ki-moon is visiting the Arctic Circle in Norway to see the melting polar ice cap for himself and draw attention to the need for action at climate change talks in December, saying it is "absolutely crucial" that world leaders take united action.
Greenland’s glaciers are both moving and melting at faster and faster rates – far quicker than the major climate models predicted. The Guardian’s Patrick Barkham filed this on-the-spot in-depth story on the calving of the ice.
A European Union ban on the manufacture and import of 100-watt and frosted incandescent light bulbs, in use since the 19th century, has come into force. They are being phased out to encourage the switch to more energy-efficient fluorescent or halogen lamps, which use up to 80% less electricity. All traditional bulbs disappear from shops across Europe in 2012.
In Copenhagen, site of the upcoming climate change summit, a third of people already cycle to work, school or university on some 350km (217 miles) of cycle routes around the city, and city officials plan to increase this to 50% by 2015. Cyclists have priority over cars and pedestrians at many major junctions and traffic lights.
Get Celsias headlines on Twitter: Celsiastweets