Loftslag og veður – öfgar aukast

Við aukna öfga í veðri, þá er eðlilegt að almenningur spyrji sig hvort þessir öfgar geti verið vegna loftslagsbreytinga og hlýnunar jarðar. Hingað til hafa vísindamenn ekki treyst sér til að segja annað en, á þann veg, að líkur á öfgum aukist með aukinni hlýnun  – vegna aukinnar orku í veðrakerfum, aukinni uppgufun og vatnsgufu í lofthjúpnum o.sv.frv.

Undanfarin misseri hafa vísindamenn farið að hugsa þetta upp á nýtt, sérstaklega í ljósi rannsókna sem sýna að hægt er að tengja saman öfga í veðri og loftslagsbreytingar (sjá Min o.fl. 2011 og Pall o.fl. 2011 – en áður var fjallað um þær rannsóknir hér – Aukin flóðahætta af völdum hnattrænnar hlýnunar). Með framförum í tölfræðitólum, loftslagslíkönum og sterkari tölvum, þá hefur þessi tenging færst frá því að vera nánast útilokuð og yfir í vera vel möguleg.

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Sjá nánar á loftslag.is - Loftslag og veður – öfgar aukast

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Heimildir og ítarefni

Þessi umfjöllun byggir mikið til á umfjöllun Nature News: Climate and weather: Extreme measures

Sjá einnig ritstjórnargrein í Nature: Heavy Weather

Heimasíða ACE – Attribution of Climate Events

Grein Min o.fl. 2011 má lesa hér (ágrip): Human contribution to more-intense precipitation extremes

Grein Pall o.fl. 2011 má lesa hér (ágrip): Anthropogenic greenhouse gas contribution to flood risk in England and Wales in autumn 2000

Grein Dole o.fl. 2011 má lesa hér (ágrip): Was there a basis for anticipating the 2010 Russian heat wave?

Sjá einnig eldri umfjöllun á Nature News: Increased flood risk linked to global warming

Tengt efni á loftslag.is

• Aukin flóðahætta af völdum hnattrænnar hlýnunar
• Eru tengsl loftslagsbreytinga og öfga í veðri ?
• Er að verða hnattræn veðurfarsbreyting?
• Óvenjulegt veður árið 2010
• Árið 2010, heitt og öfgafullt
• Tengsl milli öfgaveðurs og loftslagsbreytinga?

 

Athugasemdir

[jón spæjo (IP-tala skráð) 17.9.2011 kl. 08:36]

frábær grein,

Climate change: who cares any more?

By Simon Kuper

Published: September 17 2011 00:47 | Last updated: September 17 2011 00:47

When someone offered me a trip to India, I said, “Definitely.” A couple of years ago I’d have fretted about the carbon emissions. But like almost everyone else, I have given up trying to prevent climate change. We in the west have recently made an unspoken bet: we’re going to wing it, run the risk of climatic catastrophe, and hope that it is mostly faraway people in poor countries who will suffer.

Worries about climate probably peaked in 2007. That year I attended a workshop full of northern European policymakers and politicians. The moderator asked who believed climate change was a serious problem. Practically everyone in the room raised their hands. We then spent two days discussing action. I left feeling that if you were running a country like Britain in 2007, you probably thought climate change was the single overriding issue. Terrorism, immigration and even the economy were details by comparison.

But in 2008 the economic crisis hit. To quote political scientist Roger Pielke Jr’s “iron law”: “When policies focused on economic growth confront policies focused on emissions reductions, it is economic growth that will win out every time.” In fact, Pielke, who teaches at the University of Colorado, thinks the pre-2008 talk about action was mostly just talk anyway. “It was easier for our societies to pretend we were doing something on the issue when we felt rich, and were naive about the challenges of actually transforming our energy system,” he says. “But we never adopted any policies that had a chance to do the job.”

Nowadays few societies even pretend to be doing anything anymore. The Copenhagen global summit on climate in 2009 flopped. Carbon emissions are rising at the high end of the scenarios of the Intergovernmental Panel on Climate Change. Worse, the global economy is becoming less carbon-efficient per unit of output, as more countries turn to coal. When Japan and Germany decided to go off nuclear after the Fukushima disaster, they weren’t thinking about climate.

It’s sometimes said that democracies think too short-term to be able to tackle climate change. Well, dictatorships aren’t tackling it either. They too obey Pielke’s iron law. If they can get an extra person a car, they will. Sure, countries are developing alternative energies such as wind and solar. It’s handy to have something besides fossil fuels. But we will still consume every molecule of fossil fuel we can find.

No big state is doing enough about climate change. For the planet, it barely matters whether Barack Obama (who believes climate change is real) or Rick Perry (who doesn’t) wins next year’s US election. Obama won’t stop climate change either. Ordinary people sense the cause is lost. The wasteful minutiae of daily life that might once have worried us – running a big bath, eating a steak, idly googling old classmates – we now just do. Governments aren’t taxing this waste much.

We journalists are dropping the topic too. It’s been a thrilling year for news, but the great absence on the news sites is climate change. Max Boykoff, a colleague of Pielke’s at Colorado who tracks newspaper coverage of the issue, finds that European and north American newspapers are writing much less about it now than in 2006/7. Asian newspapers are also writing somewhat less, even though their economies are doing fine. The environment bores readers.

Almost everyone has given up. The question then becomes: what will happen? Nobody is sure. Almost all climate scientists think the outcome will be bad, perhaps catastrophic. They foresee more storms, droughts, floods and crop failures around the world, as Obama said in 2009 when he was still talking about these things. However, climate is far too complex a system to permit exact predictions. Nobody knows whether global temperatures will rise two degrees centigrade this century, nor whether that is the tipping point for catastrophe. When climate scientists make exact predictions, says Pielke, it’s usually a bid to focus the minds of politicians and voters. It hasn’t worked.

Rich countries now have a semi-conscious plan: whatever happens, we’ll have the money to cope. We’ll build dikes, or pipe in more water from somewhere else, or turn up the aircon if it gets too hot. Our model is the Netherlands: the country below sea level protects itself against flooding through a network of dams, sluices and barriers. This costs about €45 per Dutch person per year. The Dutch think that even as climate change raises sea levels, their defences can cope for another four centuries. By then there’ll be new technologies.

In short, rich countries will buy protection. If they need to abandon vulnerable cities like New Orleans or Venice, they will. The bigger problem is for poor countries. If Bangladesh floods or Nigeria dries up, they probably won’t cope well. But then our mental health in the west is built on not worrying too much about what happens to Bangladeshis or Nigerians.

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