10 years to avoid climate change catastrophe, warns Met Office
Carbon emissions must start to fall within 10 years to limit the global temperature rise to the crucial 2C mark, experts at the Met Office warned.
Even if emissions peaked in 2020, there would be a 50/50 chance of temperatures rising by more than two degrees and heralding potential global catastrophe, scientists told the Copenhagen climate change conference.
Leading industrialised nations have agreed that global warming should be limited to 2C above pre-industrial levels to avoid "dangerous" climate change, and it is one of issues being debated in Denmark.
The Met Office's Avoid study - carried out with several other British scientific groups - found that limiting the rise to 1.5C was now "virtually impossible" because of all the greenhouse gases already pumped out.
That goal has been called for by some poor African countries and small island states - areas of the world seen as being most at risk from global warming.
Even if emissions were suddenly reduced to nothing, there would still be a rise of 1.3C because of the existing greenhouse gases in the atmosphere, Avoid has found.
Researchers calculated that if emissions started falling by 4% per year after 2018 that would give a 50% chance of keeping warming below 2C.
But if the peak came just two years later in 2020, the decline would then have to be 5% per year to deliver the same odds.
Vicky Pope, the Met Office's head of climate science, told the BBC: "If you go to 2025 before peaking, it's virtually impossible to stay under 2C."
She added: "There's no way you'd get a 50 [er cent chance of avoiding 1.5C."
Delegates in Copenhagen heard that ensuring a reasonable chance of keeping the temperature rise under 1.5C would involve "negative emissions" - or removing CO2 from the air.
If carbon output peaks later than 2020, "geo-engineering" techniques such as mirrors in space and artificial trees would be needed to hit the 2C target.
More than 190 countries are gathered in Copenhagen for UN climate change talks.
Earlier this week the Met Office said the past decade has been the warmest period in the 160-year record of global surface temperatures.
Liam Neeson's Downton dreams
Greenland’s dark snow may start global warming ‘feedback loop’
Snowfalls are now just a thing of the past
Campaigners lobby Duchess of Cornwall to persuade her son-in-law to cease Knebworth solar farm
Climate change means rate of growth of trees has gone up by 77%
BMC GF01 Ultegra Disc Road Bike, review: Road bike brakes are going through a revolution
- 1 Mario Balotelli: Staff at arson-hit Manchester Dogs' Home convinced Liverpool striker is behind five-figure donation
- 2 Scottish independence live: Scotland gives a clear 'No' in historic referendum - as it happened
- 3 iOS 8 is full of shiny new features - but it's terrible news for app developers
- 4 Friends 20th anniversary: Six things we wouldn't have without influential comedy series
- 5 Scottish independence: Tory revolt against 'devo max' grows as Rail Minister Claire Perry joins
Daniele Watts: Django Unchained actress detained by Los Angeles police after being mistaken for a prostitute
Scottish independence referendum: A nation divided against itself
Scottish independence: David Cameron is becoming the 'George Bush of Britain'
Russia freezes Ukraine into submission: Kiev admits country doesn't have enough fuel for winter
Scottish independence: The Queen breaks silence on referendum debate – as think tank warns of £14bn black hole if Scotland votes Yes
Portuguese academic says British are 'filthy, violent and drunk'
£32000 - £42000 Per Annum: Clearwater People Solutions Ltd: Our client is curr...
£27000 - £31000 Per Annum Excellent Benefits: Clearwater People Solutions Ltd:...
£300 - £350 Per Day: Clearwater People Solutions Ltd: Our client is currently ...
Competitive Salary: Randstad Education Group: Randstad Education is urgently s...