Little time left to halt warming
Monday 24 October 2011
A lack of international will means the chances of bringing climate change under control may already be "slipping out of reach", scientists have warned.
A study by the Swiss science university ETH Zurich shows that without an early and steep cut in greenhouse gas emissions, global temperatures are not "likely" to remain less than 2C higher than pre-industrial levels. The 2C target, which experts say is needed to avert dangerous climate change, was agreed by the UN climate conference in Copenhagen in 2009.
But countries that signed up to the Copenhagen Accord have yet to commit to measures far-reaching enough to meet it, according to experts.
A voluntary agreement hammered out in the dying hours of last December's UN climate talks in the Danish capital is said to fall well short of the cuts required.
The new report, published today in the journal Nature Climate Change, sounds a further loud warning that time is running out. It suggests that for a "likely" chance (more than 66%) of holding warming below 2C by the end of this century, emissions must peak before 2020.
Emission levels will also have to drop drastically to around 44 billion tonnes in 2020, and then keep falling. By 2050, they will need to be well below 1990 levels at around 20 billion tonnes, says the research.
This is an ambitious goal. Last year's emission levels were estimated to be 48 billion tonnes. If no action is taken to reduce global emissions, experts fear they could grow to 56 billion tonnes in 2020.
Authors of the new study, led by Dr Joeri Rogeli, from the Swiss science university ETH Zurich, wrote: "Without a firm commitment to put in place the mechanisms to enable an early global emissions peak followed by steep reductions thereafter, there are significant risks that the 2C target, endorsed by so many nations, is already slipping out of reach."
The scientists base their conclusions on a comprehensive risk analysis of emission scenarios.
The research takes into account results from a number of previous integrated assessment models on climate change. These incorporate data from a range of different disciplines and are designed to inform policy.
Three pathways were identified that could result in a "very likely", or more than 90%, chance of not exceeding the 2C threshold.
All involved a peak during this decade, high post-peak reduction rates, net negative emissions, and heavy use of renewable energy sources and carbon capture technology.
Scenarios showing peak emissions around 2030 were likely to keep warming below 3C, but would miss the 2C target. Another study published in Nature Climate Change suggests that if greenhouse gas emissions continue to rise, the 2C threshold could be crossed between 2040 and 2060. This is well within the lifetime of many people alive today.
The research examines the idea of looking at climate change projections from a different angle, shifting the emphasis from "what" to "when".
Lead author Dr Manoj Joshi, from the University of Reading, said: "It is not just about avoiding potentially dangerous climate change, but also about buying time for adaptation.
"This approach to communicating the impacts and uncertainties of climate change draws attention to rates of change rather than just the change itself. It complements existing methods, and should be employed more widely."
Feed ducks frozen peas instead of stale bread, charity asks
Kielder Forest considered as site for return of wild lynx to the UK after 1,300 year absence
The ugliest animals on earth: Blobfish, axolotl and proboscis monkey battle it out to be named least attractive beast
Snowfalls are now just a thing of the past
Have you heard 'the hum'? Mystery of Earth's low droning noise could now be solved
- 1 Alan Rickman admits editing 'terrible' script with friends in Pizza Hut behind backs of writers on Robin Hood: Prince of Thieves
- 2 Rarest Beanie Baby of them all could be sold for £62,500 on eBay
- 3 Driving while dehydrated can be just as dangerous as drink driving, study suggests
- 4 Ben Affleck asked TV chiefs to hide slave-owning ancestry, new hacked Sony emails published by Wikileaks claim
- 5 Farmer told to tear down mock-Tudor castle after hiding construction behind hay bales
If I’m being racially abused I don’t need a stranger with a saviour complex to rescue me
The only black face in the Ukip manifesto is on the page about overseas aid
Ukip is the only main political party to not address LGBT rights in its manifesto
Food banks: One million Britons will soon be using them, according to Trussell Trust
Religion isn't growing, it is becoming vigorous in its demise, says philosopher AC Grayling
BBC election debate: The one photo that summed up the whole 90-minute leaders debate
£18000 - £23000 per annum: Recruitment Genius: They work with major vehicle ma...
£16500 per annum: Recruitment Genius: A Chiropractic Assistant is needed in a ...
£18000 - £26000 per annum: Recruitment Genius: They work with major vehicle ma...
£28000 - £30000 per annum: Recruitment Genius: This company provides coaching ...