A rise of two degrees centigrade in global temperatures -- the point considered to be the threshold for catastrophic climate change which will expose millions to drought, hunger and flooding -- is now "very unlikely" to be avoided, the world's leading climate scientists said yesterday.
The latest study from the United Nation's Intergovernmental Panel on Climate Change (IPCC) put the inevitability of drastic global warming in the starkest terms yet, stating that major impacts on parts of the world -- in particular Africa, Asian river deltas, low-lying islands and the Arctic -- are unavoidable and the focus must be on adapting life to survive the most devastating changes.
For more than a decade, EU countries led by Britain have set a rise of two degrees centigrade or less in global temperatures above pre-industrial levels as the benchmark after which the effects of climate become devastating, with crop failures, water shortages, sea-level rises, species extinctions and increased disease.
Two years ago, an authoritative study predicted there could be as little as 10 years before this "tipping point" for global warming was reached, adding a rise of 0.8 degrees had already been reached with further rises already locked in because of the time lag in the way carbon dioxide the principal greenhouse gas is absorbed into the atmosphere.
The IPCC said yesterday that the effects of this rise are being felt sooner than anticipated with the poorest countries and the poorest people set to suffer the worst of shifts in rainfall patterns, temperature rises and the viability of agriculture across much of the developing world.
In its latest assessment of the progress of climate change, the body said: "If warming is not kept below two degrees centigrade, which will require the strongest mitigation efforts, and currently looks very unlikely to be achieved, the substantial global impacts will occur, such as species extinctions, and millions of people at risk from drought, hunger, flooding."
Under the scale of risk used by IPCC, the words "very unlikely" mean there is just a one to 10 per cent chance of limiting the global temperature rise to two degrees centigrade or less.
Professor Martin Parry, a senior Met Office scientist and co-chairman of the IPCC committee which produced the report, said he believed it would now be "very difficult" to achieve the target and that governments need to combine efforts to "mitigate" climate change by reducing CO2 emissions with "adaptation" to tackle active consequences such as crop failure and flooding.
Speaking at the Royal Geographical Society, he said: "Ten years ago we were talking about these impacts affecting our children and our grandchildren. Now it is happening to us."
"Even if we achieve a cap at two degrees, there is a stock of major impacts out there already and that means adaptation. You cannot mitigate your way out of this problem... The choice is between a damaged world or a future with a severely damaged world."
The IPCC assessment states that up to two billion people worldwide will face water shortages and up to 30 per cent of plant and animal species would be put at risk of extinction if the average rise in temperature stabilises at 1.5C to 2.5C.
Professor Parry said developed countries needed to help the most affected regions, which include sub-Saharan
Rajendra Pachauri, the chairman of the IPCC, said that 2015 was the last year in which the world could afford a net rise in greenhouse gas emissions, after which "very sharp reductions" are required.
Dr Pachauri said the ability of the world's most populous nations to feed themselves was already under pressure, citing a study in
Campaigners said the IPCC findings brought added urgency to the EU's efforts to slash emissions. John Sauven, executive director of Greenpeace, said: "The EU needs to adopt a science-based cap on emissions, ditch plans for dirty new coal plants and nuclear power stations that will give tiny emission cuts at enormous and dangerous cost, end aviation expansion and ban wasteful products like incandescent lightbulbs."
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The effects of climate change will be felt sooner than scientists realised and the world must learn to live with the effects, experts said yesterday.
Martin Parry, a climate scientist with the Met Office, said destructive changes in temperature, rainfall and agriculture were now forecast to occur several decades earlier than thought. He said vulnerable people such as the old and poor would be the worst affected, and that world leaders had not yet accepted their countries would have to adapt to the likely consequences.
Speaking at a meeting to launch the full report on the impacts of global warming by the Intergovernmental Panel on Climate Change (IPCC), Professor Parry, co-chairman of the IPCC working group that wrote the report, said: "We are all used to talking about these impacts coming in the lifetimes of our children and grandchildren. Now we know that it's us."
He added politicians had wasted a decade by focusing only on ways to cut emissions, and had only recently woken up to the need to adapt. "Mitigation has got all the attention, but we cannot mitigate out of this problem. We now have a choice between a future with a damaged world or a severely damaged world."
The international response to the problem has failed to grasp that serious consequences such as reduced crop yields and water shortages are now inevitable, he said. Countries such as
Rajendra Pachauri, chairman of the IPCC, said: "Wheat production in
The summary chapter of yesterday's report was published in April, after arguments between scientists and political officials over its contents. Prof Parry said: "Governments don't like numbers, so some numbers were brushed out of it."
The report warns that Africa and the Arctic will bear the brunt of climate impacts, along with small islands such as
It says extreme weather events are likely to become more intense and more frequent, and the effect on ecosystems could be severe, with up to 30% of plant and animal species at risk of extinction if the average rise in global temperatures exceeds 1.5C-2.5C. The consequences of rising temperatures are already being felt on every continent, it adds.
Prof Parry said it was "very unlikely" that average temperature rise could be limited to 2C, as sought by European governments. That would place 2 billion more people at risk of water shortages, and hundreds of millions more will face hunger, the report says.