In yet another dramatic warning the World Meteorological Organisation (WMO) has said atmospheric volumes of greenhouse gases blamed for climate change hit a new record in 2012.
“For all these major greenhouse gases the concentrations are reaching once again record levels,” WMO Secretary-General Michel Jarraud told a news conference in Geneva.
Reuters Newsagency reports Mr Jarraud was presenting the United Nations climate agency’s annual Greenhouse Gas Bulletin.
Mr Jarraud said the accelerating trend was driving climate change, making it harder to keep global warming to within two degrees Celsius, a target agreed at a Copenhagen climate summit in 2009.
“This year is worse than last year, 2011 and 2011 was worse than 2010,” he said.
“Every passing year makes the situation somewhat more difficult to handle, it makes it more challenging to stay under this symbolic two degree global average.”
Reuters reports greenhouse gas emissions are set to be 8-12 billion tonnes higher in 2020 than the level needed to keep global warming below two degrees, the UN Environment Program said earlier this week.
If the world pursues its “business as usual” trajectory, it will probably hit the two degree mark in the middle of the century, Mr Jarraud said,.
He noted that this would also affect the water cycle, sea levels and extreme weather events.
“The more we wait for action, the more difficult it will be to stay under this limit and the more the impact will be for many countries, and therefore the more difficult it will be to adapt.”
He said the ocean dominated the climate system rather than the atmosphere, and the time needed to warm the seas meant the full impact of current emissions would only be felt later.
“Even if we were able to stop today, we know it’s not possible, the ocean would continue to warm and to expand and the sea level would continue to rise for hundreds of years.”
Delegates from over 190 nations meet in the Polish capital, Warsaw, next week for a UN conference to work on emission cuts under a new climate pact to be signed by 2015, but to come into force only in 2020.
The WMO bulletin said the volume of carbon dioxide, or CO2, the primary greenhouse gas emitted by human activities, grew faster in 2012 than in the previous decade, reaching 393.1 parts per million (ppm), 41 per cent above the pre-industrial level.
The amount of the gas in the atmosphere grew by 2.2ppm, higher than the average of 2.02ppm over the past 10 years.
Carbon dioxide was very stable and is likely to remain in the atmosphere for a long time, Mr Jarraud said.
The concentrations were the highest for more than 800,000 years, he said.
“The increase in CO2 is mostly due to human activities,” Mr Jarraud said.
“The actions we take now or don’t take now will have consequences for a very, very long period.”
The second most important greenhouse gas, methane, continued to grow at a similar rate to the past four years, reaching a global average of 1819 parts per billion (ppb) in 2012, while the other main contributor, nitrous oxide, reached 325.1ppb.
In Australia Dr Pep Canadell, Executive Director of the Global Carbon Project at CSIRO, commented: “The new trends in atmospheric greenhouse gases are the definitive proof of the unprecedented and relentless human impact on the planet.
“The fact is that current efforts to address climate change are not enough to stabilise the climate system.”
Professor Peter Rayner, a carbon cycle expert and a Professorial Fellow at the School of Earth Sciences and at the University of Melbourne, said: “The bad news is that these numbers were so predictable.
“The apparent inexorable upward trend continues.
“The good news is there were no nasty surprises. I
“n particular the local evidence we see for permafrost melting and methane releases isn’t yet visible in the atmosphere as a whole.
“The numbers tell us the main game is the burning of fossil fuel.
“Until we get to work on that problem these yearly summaries will remain signposts to failure.”
