Met Office: Global temperatures to rise 4C by 2060

Published by Jon Land for 24dash.com in Environment

Global temperatures are likely to rise by more than 4C before the end of the century without action to cut greenhouse gas emissions, scientists warned as the latest round of climate talks got under way today.

And rising levels of emissions, along with "feedbacks" in the climate system which could speed up the rate of warming, could lead to temperature rises of 4C by 2060 - within many people's lifetimes, the Met Office Hadley Centre said.

The researchers warned of "dangerous" temperature rises as negotiators gathered in Bangkok to discuss a new treaty on cutting emissions, ahead of crunch talks in December in Copenhagen aimed at agreeing a deal.

Changes in temperature, which in some areas could exceed 10C, and in rainfall could have serious consequences for food security, water resources and people's health, the study presented at a conference in Oxford today warned.

Temperature rises in the Arctic could exceed more than 15C, with intensive burning of fossil fuels, while southern and western Africa could see warming of up to 10C.

Rainfall could decrease by more than a fifth in some areas, with reductions in the amount of rain in parts of Africa, Central America, the Mediterranean and parts of coastal Australia.

But in other areas, such as India, rainfall could increase by more than 20%, leading to a higher risk of flooding from rivers, the study said.

A spokesman for the Department for Energy and Climate Change (Decc) said the research showed global warming could exceed 4C if emissions continued to rise unchecked.

"A rise of this scale would have serious consequences for the global community with food security, water availability and health all being adversely affected.

"This report illustrates why it imperative for the world to reach an ambitious climate deal at Copenhagen which keeps the global temperature increase to below 2 degrees."

With just 70 days until world leaders are scheduled to meet in Copenhagen to finalise a new deal which aims to make significant cuts in global greenhouse gas emissions, UN climate chief Yvo de Boer warned time "has almost run out".

He told negotiators who are meeting in Bangkok for one of the last climate meetings before the talks in Copenhagen that "real progress" could be made towards achieving a deal in December.

In recent weeks UK ministers have warned attempts to achieve a new deal hang in the balance and could fail.

Dr Richard Betts, who was presenting the study today at a conference at Oxford University examining the consequences of 4C temperature rises, warned: "Four degrees of warming averaged over the globe translates into even greater warming in many regions, along with major changes in rainfall.

"If greenhouse gas emissions are not cut soon then we could see major climate changes within our own lifetimes."

The paper, led by Michael Sanderson, of the Met Office Hadley Centre, updates the Intergovernmental Panel on Climate Change's (IPCC) findings in 2007, warning that 4C rises could happen sooner and with fewer emissions than previously thought.

Dr Debbie Hemming, who co-authored the paper, said a 4C rise by 2060 was "certainly not implausible".

The impacts of increasing greenhouse gas emissions could be felt sooner and more strongly because of "feedbacks" in the carbon cycle, which had not been included in the IPCC results, she said.

These include the impacts of warming temperatures on forests which may die back, releasing more carbon dioxide, and on oceans which would absorb less CO2 as they warm, as well as the increase in decomposition of organic matter in the soil which would put more CO2 back into the atmosphere.

For the UK, the changing climate could spell rises of around 5C-6C, with hotter drier summers, warmer wetter winters and an increased likelihood of heavy rainstorms and the flooding they can bring.

The study called for global emissions to peak within the next decade and then decrease rapidly in a bid to try to avoid temperatures rising more than 2C across the world.

David Norman, director of campaigns for conservation charity WWF-UK, said: "Yet again, the over-riding message from the scientists is abundantly clear - climate change is real, it's happening faster than previously anticipated and the implications for both people and the environment are potentially severe.

"Politicians have already pledged to keep the world below a 2 degree temperature rise, but the window of opportunity to make this more than an empty promise is rapidly closing."

He said the Copenhagen talks had the potential to help protect the lives and livelihoods of millions of people who would be at risk from the impacts of climate change such as an increase in the number of severe storms, and that the "time for stalling has long since passed".

Delegates at the UN negotiations in Bangkok needed to make real commitments this week to show they understood the urgency of the situation and produce a strong and fair deal in Copenhagen in December, he said.