A hellish vision of a world warmed by 4C within a lifetime has been set out by an international team of scientists, who say the agonisingly slow progress of the global climate change talks that restart in Mexico today makes the so-called safe limit of 2C impossible to keep. A 4C rise in the planet's temperature would see severe droughts across the world and millions of migrants seeking refuge as their food supplies collapse.
"There is now little to no chance of maintaining the rise in global surface temperature at below 2C, despite repeated high-level statements to the contrary," said Kevin Anderson, from the University of Manchester, who with colleague Alice Bows contributed research to a special collection of Royal Society journal papers published tomorrow. "Moreover, the impacts associated with 2C have been revised upwards so that 2C now represents the threshold [of] extremely dangerous climate change."
The new analysis by Anderson and Bows takes account of the non-binding pledges made by countries in the Copenhagen Accord, the compromise document that emerged from the last major UN climate summit, and the slight dip in greenhouse gas emissions caused by the economic recession. The scientists' modelling is based on actual tonnes of emissions, not percentage reductions, and separates the predicted emissions of rich and fast-industrialising nations such as China. "2010 represents a political tipping point," said Anderson, but added in the report: "This paper is not intended as a message of futility, but rather a bare and perhaps brutal assessment of where our 'rose-tinted' and well-intentioned approach to climate change has brought us. Real hope and opportunity, if it is to arise at all, will do so from a raw and dispassionate assessment of the scale of the challenge faced by the global community."
A rise of 4C could be seen as soon as 2060 in a worst case scenario, according to research in the same journal, led by the Met Office's Richard Betts and first revealed in the Guardian last year. Betts accepts the scenario is extreme but argues it is also plausible given the rapidly rising trend in emissions.
Rachel Warren, at the University of East Anglia, described a 4C world in her research paper: "Drought and desertification would be widespread ... There would be a need to shift agricultural cropping to new areas, impinging on [wild] ecosystems. Large-scale adaptation to sea-level rise would be necessary. Human and natural systems would be subject to increasing levels of agricultural pests and diseases, and increases in the frequency and intensity of extreme weather events."
Warren added: "This world would also rapidly be losing its ecosystem services, owing to large losses in biodiversity, forests, coastal wetlands, mangroves and saltmarshes [and] an acidified and potentially dysfunctional marine ecosystem. In such a 4C world, the limits for human adaptation are likely to be exceeded in many parts of the world."
Another Met Office study analyses how a 4C rise would differ from a 2C rise, concluding that threats to water supplies are far worse, in particular in southern Europe and north Africa, where regional temperatures would rise 6-8C. The 4C world would also see enhanced warming over most of the US, Canada and northern Asia.
In sub-Saharan Africa, "the prognosis for agriculture and food security in a 4C world is bleak", according Philip Thornton, of Kenya's International Livestock Research Institute, who led another research team. He notes there will be an extra billion people populating the continent by 2050.
"Croppers and livestock keepers in sub-Saharan Africa have in the past shown themselves to be highly adaptable to short- and long-term variations in climate. But the kind of changes that would occur in a 4C+ world would be way beyond anything experienced in recent times. It is not difficult to envisage a situation where the adaptive capacity and resilience of hundreds of millions of people could simply be overwhelmed by events," Thornton's team concludes.
Another team tackled another complex question: what would happen to humid tropical forests in a 4C world? There was the risk of forest die-off in the Amazon, central America and parts of Africa, but some regions, eg around the Congo basin, would have the potential for forest expansion. The scientist noted, however, that in practice deforestation might be the most important factor.
The speed – as well as the size – of the temperature rise is crucial too, warned scientists from Oxford University, as faster rates of global warming could outpace the ability of human civilisation and the natural world to adapt. "Dangerous climate change depends on how fast the planet is warming up, not just how hot it gets," said Myles Allen of Oxford University's department of Pphysics. "It's not just how much we emit, but how fast we do so."
Comments in chronological order (Total 461 comments)
Post a comment29 November 2010 12:23AM
Yes these dangers are real. It is also good to see that science has learned from the Copenhagen debacle and is using information to combat the disinformation. Unfortunately, I can already hear the squeals of the contrarians. They will say this is scaremongering, propaganda, and the product of some sort of scam to make money out of measures to combat climate change. What will follow is the normal tiresome squabble in which the contrarians with little grasp of the science, will use their own cobbled together arguments to try and nullify the science. Those with more insight into the science will try to point out where they are going wrong. The contrarians will take no notice of this and nothing will be achieved.
Incidentally there is a typo in the penultimate line "Pphysics" instead of "Physics".
29 November 2010 12:26AM
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29 November 2010 12:31AM
Good grief, this makes for depressing reading. It's hard to see any light at the end of the tunnel, especially with such a lack of political will at the Cancún COP16 climate talks.
Incidentally, as a semantic aside, there are some very bad editorial errors in this article. There is even whole text missing!
29 November 2010 1:03AM
As another aside. I think most people, including some apparently quoted in the article, fail to understand how this climate change will impact on human society. Modern human societies, especially in the developed world, rely on a complex infra-structure to support and feed their population. This infra-structure is based on an economy, which is linked to the world financial market. Such financial markets are set up in such a way as to feed off optimism and growth. The flip-side of this mechanism, is that if pessimism or a crisis looms, these markets go into meltdown.
If the impacts of climate change are anywhere near that predicted, the financial markets would be hit by crisis after crisis long before the really serious effects are felt.
It is one thing to talk about what counter-measures we will use to address this changing climate, but who is going to do this, and how will they do it? Look how the credit crunch crippled our governments and forced them into unpopular actions, whose full effects have yet to be experienced. Yet we have never faced a global environmental crisis before. How are these hugely weakened governments going to be in a position to put in place a cohesive strategy to address the problem? As in over 20 years they have so far failed to produce any meaningful response to the problem? This despite most governments having accepted the science a long time ago. Also in the last 20 years it is has been a period of relative prosperity, which will rapidly disappear in the face of a crisis. Who is going to invest in anything if it is likely it will get worse?
We had an opportunity over 20 years ago to re-structure our economies on a proper sustainable development footing i.e. to do away with the need for continuous growth, and a fiercely competitive international market which drives the need for growth. But we squandered that chance, and instead we upped the ante with globalisation, making our economies far more vulnerable to an international crisis. When are we going to learn?
29 November 2010 1:19AM
Did this study overlook the big freeze in South America during July and August and of course the late Autumn freeze here in the UK?
All of this hype and propaganda based on a minute bit of man made CO2 is just crazy. Once again, councils have spent their time and our money on warming and for the third winter in a row will be caught wanting for another freezing winter while the Eco nut jobs only think of warming.
With 37% of UK's electricity produced from gas, expect the lights to go out. Don't expect stupid, expensive, imported wind turbines to make up the difference either.
Low carbon / high carbon will not make a noticeable difference on nature and climate except on futurologists rigged models.
This scam has to end soon so lets have the debate now and get it done with based on actual facts we do know about. Please...
29 November 2010 1:45AM
@Sceptic999
The problem is that the natural CO2 in the atmosphere is reabsorbed via the ocean or vegetation. This way balance is preserved. Anthropogenic CO2 upsets this natural balance, resulting in a surplus of CO2 in the atmosphere, which results in increased warming patterns.
29 November 2010 1:50AM
This is news? They do it every week, though the number of degrees C. moves around a bit; "could" being the key word as usual.
29 November 2010 2:01AM
See article in The New Republic by Prof. Timothy Snyder, "The Coming Age of Slaughter: Will global warming unleash genocide?" , Oct. 28, 2010. He contends that had food been bountiful in Europe in the 20s as they were by the 1960s, it is very unlikely that the Nazi and Stalinist regimes would have taken the forms they did, as he writes in "Bloodlands: Europe Between Hitler and Stalin". Maybe we can spare ourselves not only environmental collapse, but also the idealogies of mass murder that will tempt leaders with violent solutions to environmental problems. China is still run by a party that oversaw the starvation of around 30 million people between 1958 and 1961. Nixon did not bring this up with Mao in the 1972 meeting. Jeez, I wonder why.
29 November 2010 2:09AM
Did the paper happen to mention what the optimum temperature for Gaia is?
29 November 2010 2:31AM
ImranCan
"like how did the Maldives (which are allegedly threatened with 'innundation') survive the 100m sea level rise in the last 12,000 years ??? HOW DID THAT HAPPEN ? Duh."
Your answer is in your question. 12,000 years ago there was a glaciation that retained enough water for the sea levels to be 100m lower than they are today. The Maldives and any other land was 100m+ above sea level back then. And also, sea levels have been stable for over 4000 years which, gave these corral reeves, i.e. growing organisms, some time to get to the state they are now.
The point is that due to current warming trends the rest of the ice sheets that remained are indeed melting, rising sea levels above levels that have existed for the last 4000+ years.
29 November 2010 2:38AM
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29 November 2010 2:45AM
Orkneygal
"Did the paper happen to mention what the optimum temperature for Gaia is?"
The optimum temperature is irrelevant. The problem is not that the climate changes as such. The point is that it changes too quickly. Human society has developped over the last 4000 years in a relatively stable environnement/climate.
The trend of the warming currently occuring because of greenhouse gases released by human activity seems to be heading for off the charts records in a period of time uncommon with natural climate variation time frames. Simply put, too much, too fast. Hence a very high risk human society will not be able to adapt quickly enough and break down.
29 November 2010 2:47AM
@RadicalThinking
The Maldives and any other land was 100m+ above sea level back then.
I'm not even sure where to start with this ..... basic geology, basic education ..... ? where do I begin ? I would suggest Charles Darwin on the formation of atolls .....but I think it would be pointless.
29 November 2010 2:47AM
if, could, would, maybe, perhaps blah blah ... in the meantime IT IS f'ing freezing and snowing outside!
29 November 2010 3:00AM
ImranCan
You said yourself sea levels have risen 100m in 12,000 years. That means land was 100m above sea levels 12,000 years ago.
Islands like the maldives are corrals reeves which are living breezing organisms. Atols are built by successive layers of dead corral growing on top of each other. So corrals do follow sea levels.
However, the current problem is that the warming + the acidification of waters are killing corrals so they cannot follow sea levels anymore.
29 November 2010 3:10AM
from the article:
.
This sort of speculative conclusion is pure, regurgitated alarmist rubbish.
How can a rise of 4 degrees C in ave. global temps cause widespread droughts? Rainfall patterns may or not be different today but surely a warmer climate will produce more evaporation from the oceans and more precipitation.
29 November 2010 3:13AM
should read:
29 November 2010 3:18AM
GThynne
"surely a warmer climate will produce more evaporation from the oceans and more precipitation."
Yes you are right, as recent floodings have proved. However, more precipitation doesn't mean they are evenly spread whether geographically or in time. Hence more severe droughts during dry seasons in between heavier precipitation in wet seasons is the most likely pattern. And this is pretty much what is already happening, like the fires in russia and the flooding in pakistan.
29 November 2010 3:24AM
After reading the East Anglia climategate emails between high level AGW "scientists" conspiring to blacklist researchers and publications for discovering contrary evidence - I lost interest in the whole climate parade charade.
I know, five "independent" panels found that it was OK for scientists to confuse science with politics.
But this particular article was quite entertaining. Lots of good apocalyptic speculation about what "could" happen "if" all of the worst case scenarios predicted by computer models proved true - none of which have proven true to date.
But it would make a great SyFy channel disaster movie.
Funny how people just aren't happy unless they can huddle in fear pretending that the end of the world is near.
To quote the melodious Talking Heads: Same as it ever was. Same as it ever was.
29 November 2010 3:25AM
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29 November 2010 3:33AM
"
It's too late
But it's not too late.
29 November 2010 3:44AM
RadicalThinking
No, recent floodings do not prove your assertion that precipitation in a warming world will be more intense but less frequent.
As I said in my previous post, the assertion that a warmer world will lead to widespread droughts is merely speculation designed to alarm
29 November 2010 3:49AM
Whew!! Just in time for Mexico and putting the wind up the Fly-in holiday makers oops sorry delegates.
There is much talk of peak oil, someone hinted at peak coal and peak this and that. Amid all this gloom and doom, this article may signal the arrival of peak alarmism.
29 November 2010 4:25AM
One can accept that climate is changing, some places will get warmer and some colder, some places will get wetter and some drier; this is a natural process. I am unsure if this is caused or aggravated by man, it’s not my area of expertise (not that I have one).
Isn’t it time to accept that trying to get a consensus on reducing emissions in a reasonable time frame is not possible. Every country will have a position and this position is unlikely to change because of numerous local reasons. Politicians have been talking about this for decades and seem no closer to consensus.
If one accepts that consensus cannot be achieved in the required time frame, what is being done to investigate/implement measures that can counter or slow down change?
Charges are being levied for various products and services to try and reduce emissions but what is happening to this money. Is it being hypothecated into measures to improve the situation or is it just being thrown into government coffers as an extra tax measure used for many non-climate related activities.
I personally would have more belief in Climate change if I saw that the extra costs I am incurring are being used to resolve/alleviate the situation.
Rather than the UN being involved in non-production conferences they should start investigating remedies that do not rely on countries radically changing their habits.
This doesn’t mean that countries can ignore the issue. Each country should be trying to be a good steward of the piece of Earth that they have been granted.
29 November 2010 6:32AM
Not science....
Alchemy!
29 November 2010 7:06AM
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29 November 2010 7:06AM
kennymac825
Peak alarmism, rfol. Nice one Kenny.
29 November 2010 7:09AM
4 degrees C globally by 2060 and e.g. in southern Europe 6-8 degrees.... so in some places we would see warming rates of over 1 degree per decade.
When is this warming going to take place? Right now we see warming of 0.1-0.2 degrees per decade and no signs of rate picking up? Or will the warming come all of a sudden?
29 November 2010 7:11AM
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29 November 2010 7:17AM
Its just this kind of unwarranted unsubstantiated alarmism that makes me certain that its all a scam. How studip do they think we are?
29 November 2010 7:30AM
SteB1
Says you. And what makes the warmists right? So-called science? They think we know so much but weathers not rocket surgery. You grasp and cobble lol
29 November 2010 7:37AM
Yawn................................ here we go again.
29 November 2010 7:41AM
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29 November 2010 7:42AM
runner911
Don't hang around if you dont want too. Some of us have got lives to go to. If we can get through the blizards.
29 November 2010 7:44AM
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29 November 2010 7:45AM
saigonio
Right on dude. Stop lying to us and maybe we'll belive you.
29 November 2010 7:48AM
antipodean1
No I referenced this article which you would know if you had bothered to read my post.
29 November 2010 7:49AM
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29 November 2010 7:52AM
Gneiss
N* shit.
29 November 2010 7:56AM
Do they think they get more credible if their predictions become more extreme?
Thought process: okay, we've lost the argument on risk. Few people think there's much of a risk that human activity will heat the world. Therefore, if we make the consequences really, really bad, people will worry about the risk even if they think it is small.
Come on, guys. We aren't that stupid.
Oh, and I like the 2060 date for the end of the world. Far enough away that we'll mainly be dead before it happens, like all the best doomsday cults. Always a mistake to prophecy doom in the near future, like the poor Jehovah's Witnesses in the early 20th century.
29 November 2010 7:59AM
@CO2Central
All together now!
Correlation is not causation!
29 November 2010 7:59AM
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29 November 2010 8:06AM
Learnt nothing.
It seems this author - along with many of his Guardian/Observer colleagues - hax learnt nothing from Climategate, the failure of Copenhagen, and even the wrist slapping enquiries on Climategate and IPCC errors. These 'enquiries', as a minimum recommended a toning down of the scaremongering on the basis it is counter-productive.
You are doing precisely the same as the lead up to Copenhagen. Roll out a batch of hastily written articles making the case for doing something desparate to stop AGW. But for every such article, you create more AGW sceptics. The claims and predictions are so far fetched, the amount to a primeval characteristic of mankind - to fear that The End of the World is Nigh.
And despite the claims of trolling warmist commentors, such views are not 'head in the sand'. On the contrary, we have many genuine problems that are killing millions of people every year, that we routinely fail to to adress. To be focusing so much attention on a theory (record CO2 emissions in 2009, but no warming for past 12 years - unless you are artistic with moving means) verges on the obscence.
At least such articles - and many of the comments - remain entertaining.
29 November 2010 8:09AM
Bearing in mind that the only 'proof' of 3 K climate sensitivity is the 'cloud albedo effect' part of global dimming for which there's no experimental proof and the theory is plain wrong, how can you justify this alarmist article?
The experimental reality is that climate sensitivity is <<1 K so no problemo.
29 November 2010 8:09AM
There are no bounds to the stupidity and greed of some people.
29 November 2010 8:19AM
Hmm. With a 4c rise people might be able to get to work today.
29 November 2010 8:44AM
duncanm
Look what happened to them. All dead obviously. And does anybody think the so-called climate made a difference? Warmisms just another religion.
29 November 2010 8:45AM
Does this stream-of-consciousness drivel from the UEA representative:
remind anybody else of the (false) prophet in Life of Brian:
"
?
29 November 2010 8:49AM
The people of the UEA have been coping with desert conditions for centuries since the days of Brian. They've got indoor ski slopes.
29 November 2010 8:52AM
Has anyone actually read the Anderson and Bows paper, and not just the article about it. I just have, although I admit it would take more time to absorb it's findings.
Firstly, I have to admit I stopped reading the literature on ACC some time back. I was personally convinced of the phenomena, and there were too many unknowns, such as would there be an agreement, or whether there would not be an agreement. So I thought I was wasting my time looking for detail with so many unknowns.
Having just read this paper it is a very sober and very sensibly written paper. To be quite frank it is shocking. I am sorry to be so blunt but you contrarians are talking out of your backsides. Get real, we are talking about the future for our children and all the children of the world. None of your crap about this being emotive - it is real unlike your pie in the sky abstract economic nonsense. You are self-centred and you are delusional if you do not think this is a real issue. So stop your pathetic rhetorical games. If you just don't want the measures to prevent ACC because of your economic idealism, then just have the guts and bravery to say this and stop dressing it up in this disingenuous scepticism about the science.
Reading the paper confirmed much of the impressions I had gained on my understanding of the issue from a while back. Firstly, as I had always suspected the 2 degree rise figures are not derived from science and is "likely to lead to dangerously misguided policies". It also seems that there is a substantial difference between modelled emissions and emissions derived from empirical data. With the actual emissions appearing to be quite a bit higher than the modelled emissions.
The authors appear to think that there is little chance of the 2 degree target being met, or even anywhere near this. It is thought that unless our economic model changes dramatically there is little hope of meeting targets. I have not yet got a grasp on all the scenarios. However, no clear picture can be drawn because so much depends on the complete unknown of how much we reduce or do not reduce our emissions. It concludes "they raise serious questions as to whether the current global economic orthodoxy is sufficiently resilient to absorb the scale of the challenge faced".
Please think again. All your cherished notions of your economic ideals face a far bigger threat from ACC, than from the measures to prevent it. Read the paper and then tell me it is a scam.