Edging toward a climate tipping point
The cost of global warming can no longer be quantified solely in terms of gross domestic product as the changes the world will experience and the resulting loss of life will be so immense, climate economist Nicholas Stern said on Wednesday.
In 2006, Stern published a major report on the economics of climate change which said average global temperatures would rise by 2 to 3 degrees centigrade in the next 50 years and could reduce global consumption per head by up to 20 per cent.
"That particular calculation had the one good model based on consumption and GDP but I would look at it now more broadly," Stern, who is chair of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics, told Reuters in an interview.
"One simple measure of cost in terms of loss of GDP or consumption is a fairly narrow way of looking at things. It doesn't get at the full nature of the risk management question," he added, referring to the massive loss of life which would likely arise from billions of people being displaced due to floods and droughts if emissions are allowed to rise.
The latest climate science shows the planet has warmed by 0.8 degrees centigrade above last century but if left unmanaged, the world could face temperatures of 4, 5 or 6 degrees higher this century, Stern said.
The planet has not experienced such temperature rises for millions of years, he added.
If countries deliver the top end of emissions cut targets, emissions would plateau at 50 billion tonnes per annum carbon dioxide equivalent but they need to fall below 35 billion tonnes by 2030 and 20 billion by 2050 to have a 50-50 chance of limiting temperature rise to below 2 degrees this century.
"We are not really starting to bring emissions down, at best we might be holding them," Stern said.
A 4, 5 or even 6 degree world is difficult to describe, but many areas will turn into deserts, countries will submerge and the whole pattern of the north Indian monsoon might change which shapes the activity of hundreds of millions of people in the most densely populated parts of the world, he said.
"Southern Europe looking like the Sahara desert, Bangladesh under water – these are the kinds of things that could happen."
Most climate models have underestimated the risks as they omit the timing and consequences of "tipping points", or thresholds beyond which a small additional rise in average temperature results in irreversible changes, Stern warned.
Stern said investment equivalent to 2 per cent of global GDP was needed to limit, prevent and adapt to climate change.
Rich countries have pledged to find $100 billion a year by 2020 to help poorer countries adapt to climate change. The United Nations' Green Climate Fund is designed to channel some of that money but is so far an empty vessel.
"We always argued $100 billion was on the low side. In terms of the extra investment needed, figures of $200-300 billion are probably in the right ballpark," Stern said.
While waiting for the money to materialise, some of the countries most vulnerable to climate change are making plans. Ethiopia aims to move to middle-income status by 2025 without increasing its carbon emissions and China's twelfth five-year economic plan represents a radical change, Stern said.
Stern is a member of the high level advisory group on climate finance which recommended various funding sources for the Green Climate Fund, like the auctioning of carbon permits, taxation on aviation and shipping activities and the abolition of fossil fuel subsidies.
These could deliver around half the $100 billion needed by 2020, based on an assumption of a $20-25 a tonne carbon price.
"Over time we argued carbon markets would be building up, but it has gone slower than many including ourselves would have wished," Stern said.
On the plus side, progress on clean technology development is moving very quickly.
The capital cost of solar photovoltaic has come down by a factor of five in the past 5-6 years and will probably fall by a further factor of two in the next two years.
The cost of onshore wind has become much more competitive and China is planning 200 more nuclear power stations in the next 20 years.
"The good news since the Stern Review is the way in which technological change has set in and governments around the world are taking this issue enormously seriously," Stern said.
Comments on this article
Tipping point...
1. One does not need to postulate a tipping point to identify the initial major problem of global warming. If sea levels rise 2 metres, a significant part of today's built urban infrastructure will become unusable and irrelevant. It will need to be rebuilt at a higher level - at great expense. I live on the Gold Coast - I can see what will happen (from a safe 75 metres above sea level).
2. The reason why the coal, oil and gas companies do not want renewable energy sources is that it will cut 90% of their revenue. Once we have harnessed photosynthesis, and its (sun powered) technological equivalents, for energy production - the generation of energy will be intrinsically at no cost. The cost of the maintenance of such power plants, and of energy distribution, will be much less. And as technology improves, continue to reduce. That is not a desired outcome.
High School Science
High school science shows us that the temperature in a vessel containing ice will remain at near zero till all the ice has melted. This is due to the latent heat of melting of the ice. The more heat you put in the more ice melts rather than the temperature rising.
While the Earth is not a vessel, global ice is still acting as a heat sink by melting instead of increases of surface, ocean and air temperatures. By making reasonably accurate estimates of the global ice lost each year we can calculate an estimate of the heat that is causing Global Warming. That heat value just happens to be the same order of magnitude as the heat released by burning fossil fuels each year. Those same fossil fuels that will be largely gone by 2050. Rapidly moving to renewable energy production for a major portion of our primary energy supply will both conserve fossil fuels for those uses that they are needed and reduce Global Warming.
Dan
Not quite
There are uncertainties regarding the net effect of clouds, that does not mean that they are overstated. In any case, uncertainty in this regard is no reassurance.
The climate is not "returning to where it has been during previous times during the Holocene epoch when the sea was metres higher". That is plainly wrong. The climate has been very stable for the last 10,000 years ( known as the holocene ).
Sea levels have indeed been higher in the mre distant past, when coincidentally CO2 levels were higher. I suggest you have a look as Prof Richard Alley's 2009 lecture to the AGU http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml that explains the paleoclimate relationship between CO2 and temperature
Speaking of cherries...
Timothy Northcott: current temps are likely as high as any during the Holocene (the current interglacial period starting ~10-12,000 years ago). What makes you think they're going to stop there?
And what makes you think sea levels are going to stop rising anywhere short of the +6 metre mark that was achieved during the Eemian interglacial, 125,000 years ago, when CO2 levels were substantially lower than they are today?
If you're going to start talking about whether CO2 is even the cause, then you'll need to come up with some other explanation as to why the gentle cooling trend that's been going on for the past 6,000 years has suddenly completely reversed itself over the past couple of centuries. Some very smart people have been working on that problem for 150 years now, and we know what answer they've come up with.
Alvin Stone: here's the link
Alvin Stone: here's the link to the relevant section of IPCC AR4:
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch11s11-3-3-2.html
Some areas of Spain, southern Italy, Greece & Turkey were predicted to have a 30-50% reduction in rainfall by the end of the century. Given some of those areas are already rather dry now, that'd be pretty bad. Perhaps not quite "Sahara", but not far short. And that's "mean" impact, not the "worst case", which is more what's described in the article above.
And pretending that low-probability outcomes don't exist merely puts blinkers over people's eyes - saying "Hey, climate change is likely to be bad", without also saying "but there's also slight chance it'll be either just a little bad, or so unbelievably bad that it's debatable that your country will even exist in a century or two".
Cherry pick
George,
Scientists are quite clear that they do not understand clouds and the models that have watervapour feedback as being overly positive are now being proved as overstating the threat of dangerous warming. The climate is just returning to where it has been during previous times during the Holocene epoch when the sea was metres higher, the arctic could be sailed through and the premafrost was no longer permanent.
Over egging
Stern's comment that Europe will look like the Sahara Desert is exactly the kind of things climate scientists don't want. This need to overplay the likely serious consequences undermines the solidity of the science when they don't appear. Tim Flannery's comments and those of various other activist types hugging the spotlight have done more harm than good.
Climate change is real, it is dangerous, it will have serious consequences but we don't need to say Southern Europe will turn into the Sahara. Serious droughts, loss of water and heatwaves are likely but desertification, because of the land forms and sea, is less so.
Cherry pick
@ Timothy Northcott - Oh great, so one study suggests clouds "could" offset some global warming. So now we can all forget about every other study showing ralid arctic melting, sea level rise, melting of permafrost etc etc
Clearly we have to include ALL the evidence not just one little bit that suits our current argument.
Cherry pick
@ Timothy Northcott - Oh great, so one study suggests clouds "could" offset some global warming. So now we can all forget about every other study showing ralid arctic melting, sea level rise, melting of permafrost etc etc
Clearly we have to include ALL the evidence not just one little bit that suits our current argument.
No Tipping Point
David,
Read: http://www.climatespectator.com.au/news/cloud-changes-could-slow-global-warming-research?utm_source=Climate%2BSpectator%2Bdaily&utm_medium=email&utm_campaign=Climate%2BSpectator%2Bdaily&utm_source=Climate+Spectator&utm_campaign=5c3694b453-CSPEC_DAILY&utm_medium=email as the evidence for negative feedbacks from clouds is starting to become evident so there will be no runaway global warming and no need to worry about tipping points.
Economists don't understand the scale of the problem
Economist consensus is shown in the paragraph "If countries deliver the top end of emissions cut targets, emissions would plateau at 50 billion tonnes per annum carbon dioxide equivalent but they need to fall below 35 billion tonnes by 2030 and 20 billion by 2050 to have a 50-50 chance of limiting temperature rise to below 2 degrees this century."
This is not what the climate science already knows, and has known for about a decade.
Highest atmospheric [CO2] for interglacial warm periods eg the Holocene is no higher than ~300 ppm.
Even with a margin of error, this means that we cannot leave atmospheric CO2 above 350 ppm for long, else we'll trigger runaway greenhouse warming - warming oceans and thawing permafrost releasing CO2 and much more powerful CH4.
What does this mean? It means rapid phasing out of all fossil fuel use as quickly as economies can manage.
Emission trading schemes, in which we agree on how much CO2 we will release, won't cut it quickly enough. Only an escalating carbon price via a fossil carbon consumption tax can do the job, by guiding and informing decisions on investment in low/zero carbon technologies and innovation.
200 more nuclear power stations....
seems the Chinese know the best way to deliver cheap emission free power.