Next decade 'may see no warming

[frigidmagi]

BBC

The Earth's temperature may stay roughly the same for a decade, as natural climate cycles enter a cooling phase, scientists have predicted.

A new computer model developed by German researchers, reported in the journal Nature, suggests the cooling will counter greenhouse warming.

However, temperatures will again be rising quickly by about 2020, they say.

Other climate scientists have welcomed the research, saying it may help societies plan better for the future.

See how modelled temperatures may develop

The key to the new prediction is the natural cycle of ocean temperatures called the Atlantic Multidecadal Oscillation (AMO), which is closely related to the warm currents that bring heat from the tropics to the shores of Europe.

The cause of the oscillation is not well understood, but the cycle appears to come round about every 60 to 70 years.


Imagine the payoff of knowing with some certainty what the next 10 years hold in terms of temperature and precipitation
Professor Michael Schlesinger

It may partly explain why temperatures rose in the early years of the last century before beginning to cool in the 1940s.

"One message from our study is that in the short term, you can see changes in the global mean temperature that you might not expect given the reports of the Intergovernmental Panel on Climate Change (IPCC)," said Noel Keenlyside from the Leibniz Institute of Marine Sciences at Kiel University.

His group's projection diverges from other computer models only for about 15-20 years; after that, the curves come back together and temperatures rise.

"In the long term, radiative forcing (the Earth's energy balance) dominates. But it's important for policymakers to realise the pattern," he told BBC News.

Deep patterns

Modelling of climatic events in the oceans is difficult, simply because there is relatively little data on some of the key processes, such as the meriodional overturning circulation (MOC) - sometimes erroneously known as the Gulf Stream - which carries heat northwards in the Atlantic.

Only within the last few years have researchers begun systematically deploying mobile floats and tethered buoys that will, in time, tell us how this circulation is changing.


Atlantic circulation

Enlarge Image

As a substitute for direct measurements of the MOC, the Kiel team used data going back 50 years from the Labrador Sea, where warm water gives up its heat to the atmosphere and sinks, before returning southward lower in the ocean.

Combining this ocean data with established models of global warming, they were able to generate a stream of model results that mimicked well temperatures observed in the recent past over the north Atlantic, western Europe and North America.

Looking forward, the model projects a weakening of the MOC and a resulting cooling of north Atlantic waters, which will act to keep temperatures in check around the world, much as the warming and cooling associated with El Nino and La Nina in the Pacific bring global consequences.

"We have to take into account that there are uncertainties in our model; but it does suggest a plateauing of temperatures, and then a continued rise," said Dr Keenlyside.

'No distraction'

The projection does not come as a surprise to climate scientists, though it may to a public that has perhaps become used to the idea that the rapid temperature rises seen through the 1990s are a permanent phenomenon.

"We've always known that the climate varies naturally from year to year and decade to decade," said Richard Wood from the UK's Hadley Centre, who reviewed the new research for Nature.

"We expect man-made global warming to be superimposed on those natural variations; and this kind of research is important to make sure we don't get distracted from the longer term changes that will happen in the climate (as a result of greenhouse gas emissions)."

Buoys. Image: Nerc
Ocean buoys should produce more data about the Atlantic oscillation

Dr Wood cautions that this kind of modelling is in its infancy; and once data can be brought directly from the Atlantic depths, that may change the view of how the AMO works and what it means for the global climate.

As with the unusually cold weather seen recently in much of the northern hemisphere - linked to La Nina conditions - he emphasises that even if the Kiel model proves correct, it is not an indication that the longer-term climate projections of the IPCC and many other institutions are wrong.

Michael Schlesinger, the US scientist who characterised the AMO in 1994, described the new model as "very exciting".

"No doubt we need to have more data from the deep ocean, and we don't have that at present," the University of Illinois at Urbana-Champaign researcher told BBC News.

"But imagine the payoff of knowing with some certainty what the next 10 years hold in terms of temperature and precipitation - the economic impacts of that would be significant."

I find myself in the emotional position of the man who just got missed by the gunman across the street. We've may have just dodged a bullet of major warming occuring in the next 10 years, giving us extra time. On the flip side there's nothing saying that it won't come back only worse, or in other words, Global Climate Change still has a full clip of ammo left to fire at us.

[Charon]

Personally, I think this is terrible news.

I have the dread that when people realize that the temperature has stopped going up a lot of them are going to go "Oh, hey. See I knew global warming was a myth! No need to start looking for alternative power sources!" And that decade is going to lead to laxity which is gonna hit us hard in 2020.

But I'm a pessimistic paranoid freak, so what do I know?

[The Grim Squeaker]

Personally, I think this is terrible news.

I have the dread that when people realize that the temperature has stopped going up a lot of them are going to go "Oh, hey. See I knew global warming was a myth! No need to start looking for alternative power sources!" And that decade is going to lead to laxity which is gonna hit us hard in 2020.

But I'm a pessimistic paranoid freak, so what do I know?

Don't worry, running out of oil will do that ;. Of course, there's the temptation to switch to coal, and to bulldoze the rainforests for biofuels like Brazil is doing...

[Charon]

Personally, I think this is terrible news.

I have the dread that when people realize that the temperature has stopped going up a lot of them are going to go "Oh, hey. See I knew global warming was a myth! No need to start looking for alternative power sources!" And that decade is going to lead to laxity which is gonna hit us hard in 2020.

But I'm a pessimistic paranoid freak, so what do I know?

Don't worry, running out of oil will do that ;. Of course, there's the temptation to switch to coal, and to bulldoze the rainforests for biofuels like Brazil is doing...

Yeah but it probably isn't going to be until 2015 at least before people on a whole start realizing that we're actually running out of oil. And levels won't get low enough to warrant change on that fact alone for at least another fifteen years after that. Coal in the West is pretty much dead, when Oil goes out as a major power source coal won't be far behind. But with China and India growing, the West is going to quickly become not the issue in terms of coal use.

Getting to other sources of energy, wind and water are absolute jokes. There have been some advancements with burning algaes to run generators but that will probably never take off. Unless we get some serious breakthroughs, solar is not going to be able to pick up the slack, we don't have enough uranium to keep fission viable for very long. Personally, I'm banking on fusion reactors. So european scientists had better hurry the fuck up on getting us a generator that has a net gain of energy.

[frigidmagi]

Read this Charon.

[SirNitram]

Oh. Great.

So all the deniers will be given ammo.

Do you know how many people now treat SARS or avian flu as a pointless crying wolf, because nothing happened? This is that on a worse scale.

[Charon]

Read this Charon.

Ah, I'd forgotten that part of the nuclear thing and foolishly paid more attention to my hippie fear-mongering Environmental Biology class movie.

I'd still prefer to not have that much radioactive waste floating about (not that it's that much... but still), but that's not a big issue unless the stuff is more harmful to the environment than the carbon dioxide we are currently pumping into the air. Which I'm fairly certain it isn't.

[Destructionator XV]

I'd still prefer to not have that much radioactive waste floating about (not that it's that much... but still), but that's not a big issue unless the stuff is more harmful to the environment than the carbon dioxide we are currently pumping into the air. Which I'm fairly certain it isn't.

Don't forget the radioactive stuff we are currently pumping into the air.

Coal has uranium and other radioactive things in it too, but unlike in a nuclear reactor where it is all contained in one place, it is just released into the air when burned.

[Mayabird]

Translation from the technical talk:

Circulation of water from the deep ocean basins takes a long time, and we don't really know much about it. It's cold water back from the Ice Age down there, and because of a bunch of stuff we don't understand but can model a bit, circulation of that cold, deep water back to the surface will increase. There's a lot of it, a huge reservoir of cold, but as it is replaced by warm surface waters of right now, it will slowly run out. And then we're screwed again.

And if you try to tell this to the scoffers, they'll act like a creationist when a scientist says that Archaeopteryx probably isn't the "first bird" or ancestor to all birds and then says that evolution is invalidated. You try to explain that things are more complicated, but they'll just claim that this one factoid that isn't entirely related to the main giant theory disproves the entire shebang and nothing will convince them. That would be fine if they didn't drag along a lot of fence-sitters with them, and we need the numbers if there are going to be the wide-scale major changes needed to avert catastrophe.

The really twisted thing is that the longer we delay things, the worse the crash will probably be because the world's population is only getting bigger.

Do you know how many people now treat SARS or avian flu as a pointless crying wolf, because nothing happened? This is that on a worse scale.

For avian flu, I would say "because nothing has happened yet." It still has the potential to become a pandemic strain like it did in 1918. Evolution doesn't stop because the media has a short attention span. Of course, it might never happen, but the flu is still jumping to humans on a regular basis, and it's all a matter of statistics when one will jump and have just the right mutations to be human to human transmittable.