Research suggests climate change target ‘not safe’
From the University of Exeter via Eurekalert
An analysis of geological records that preserve details of the last known period of global warming has revealed ‘startling’ results which suggest current targets for limiting climate change are unsafe.
The study by climate change experts at the University of Exeter has important implications for international negotiators aiming to agree binding targets for future greenhouse gas emission targets.
Professor Chris Turney and Dr Richard Jones, both from the University’s Department of Geography, have reported a comprehensive study of the Last Interglacial, a period of warming some 125,000 years ago, in the latest issue of the Journal of Quaternary Science.
Caption: This is Professor Chris Turney in the field in Svalbard. Credit: University of Exeter
The results reveal the European Union target of limiting global temperature rise to less than 2°C above pre-industrial levels shouldn’t be considered ‘safe’.
From their analysis, the scientists found 263 estimates of the conditions when sediments and ice were laid down during the Last Interglacial, allowing them to reconstruct past temperatures around the globe. To compare the reconstructed estimates with today, they took the Last Interglacial values away from modern temperatures averaged over the period 1961 to 1990.
The results show temperatures appear to have been more than 5˚C warmer in polar regions while the tropics only warmed marginally; strikingly similar to recent trends. Not only this, but taken together, the world appears to have been some 1.9˚C warmer when compared to preindustrial temperatures. Critically, the warmer temperatures appear to have resulted in global sea levels some 6.6 to 9.4 metres higher than today, with a rate of rise of between 60 to 90 centimetres per decade — more than double that recently observed.
The higher temperatures seen during the Last Interglacial are comparable to projections for the end of this century under the low emission scenarios contained within the recent Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).
Professor Turney said: “The results here are quite startling and, importantly, they suggest sea levels will rise significantly higher than anticipated and that stabilizing global average temperatures at 2˚C above pre-industrial levels may not be considered a ‘safe’ target as envisaged by the European Union and others. The inevitable conclusion is emission targets will have to be lowered further still.”
The full paper, Does the Agulhas Current amplify global temperatures during super-interglacials?, appears in the latest edition of the Journal of Quarternary Science. It can be viewed here: http://onlinelibrary.wiley.com/doi/10.1002/jqs.1423/abstract
Notes for editors:
A blog by Professor Chris Turney on this subject, called A Lesson from Past Global Warming, can be viewed on his website at www.christurney.com
sublime says:
October 1, 2010 at 2:20 pm
‘Why am I reading this bs? ‘
Because it makes a whole lot more sense than the bs you’re spouting?
Tom Bakewell says:
October 1, 2010 at 2:02 pm
Well, at least one of them is a geographer… I know that’s a lame excuse, not having expertise in or about the subject of one’s paper.
I’d rather see this sort of work done by geologist(s). But wait, we’re trained to draw lessons from the past records, which is why most of us are unimpressed by the ‘evidence’ as squeezed from ‘data’ by the AGW crowd. And like historians, why our opinions are not welcomed or valued by the samesuch folks.
As a lurking geologist, I totally agree. I live on the coastal plain in eastern Virginia, and when I hear or read about a few meters of sea level rise (not that I want it to happen), I wonder how many people are aware that ancient marine (i.e. ocean) sediments extend as far west as Richmond (and cover a good bit of the eastern portion of the mid-Atlantic states). The sediments represent several cycles of marine transgressions and regressions with sea level rises much greater than a few meters, but to the best of my knowledge, anthropogenically generated CO2 has never been postulated as the cause.
As a side note, I’d be willing to bet that a lot of AGW…er CC…CCD alarmists enjoy hunting marine fossils along the cliffs of the Chesapeake Bay, never appreciating the irony.
I think the general numbers are correct. Temps were about 2.0C to 2.5C warmer (4.0C to 5.0C at the poles and 1.0C or so warmer in the tropics) during the last interglacial. Sea level was about 5 metres higher.
CO2, however, was just 275 ppm (with one short spike at 285 ppm). So CO2 certainly did not cause it.
The Milankovitch Cycles reached a very rare high peak at the time – summer solar insolation was at a max in the far North – and in the 50,000 year lead-up to this period, it was not that low so there was not as much ice built-up beforehand that needed to be melted first in order for the peak solar insolation to have its greatest effect – both of these effects need to occur for an interglacial to actually happen and for it to have a greater impact). So lots of the ice melted in the Arctic and the planet’s Albedo was lower (probably lower than at any time in the last 400,000 years).
———————
The max limit for +2.0C from temperatures is the same as 450 ppm for CO2.
+2.0C = 3/ln(2)*ln(450/280)
It is really a CO2 target of 450 ppm, not a temperature target at all.
————–
Without in any way meaning to lend support to this article, I presume the sea level rise of 6 – 9 cm a year is a journalistic slip up. In the paper they say sea level is
“rising some 6–9 mm a−1 (Kopp et al., 2009) – at least double the current global average.” so I don’t think it’s fair to criticise/ridicule Turney on those grounds.
What troubles me more is the mixing of campaigning with science. OK, Chris Turney is a populariser but he has written campaigning articles on CAGW (e.g. We must acknowledge global warming, and act, The Times, 21 December 2007;
Time we acted on climate-change warnings, The Press, 21 February 2007). We can only be ourselves and if as scientists we are convinced (trying not to use the word ‘believe’) of the importance of some issue it’s understandable that we might contribute to the media in some way, I suppose even campaign for a cause. But (and its a big but) once you do that how do can you go on to pursue objective science?
In my research I try hard to run multiple working hypotheses (mwh), try to argue against what my current understanding suggests is true, argue against my own convictions. I suggest that unless an individual pursues mwh (and if we’ve strong convictions about something then there’s the greater need to aggressively pursue mwh) then dodgy science is the result.
The stronger your convictions, the more you think you are right and the less necessary mwh seem to be. Individually it’s not easy and corporately it is even tougher to question the ruling paradigms as the team fights against you, (with dirty tricks and all as witnessed by ClimateGate) though I take comfort that truly great individuals (e.g. Steve M) can prevail. On the other hand it’s even more dangerous to play onside, egos are flattered, mwh seem unnecessary and all manner of rubbish slips through if you say the right things. It’s a lesson for WUWT. And if climate scientists (if that’s what they are) had pursued mwh we’d have been saved a lot of grief, including being beaten about by hockey sticks or the hubris of believing we can agree “to the historic deal setting 2 degrees Celsius as the maximum limit for global temperature rise.”
Whatever the shortcomings or otherwise of the abovementioned study, there is a welter of information indicating a doubling of CO2 will likely lead to a global average temperature increase in excess of 2C. Please read a review of various approaches by Knutti and Hegerl 2008 at http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf.
The paper breaks estimate approaches into:
– instrumental period
– current mean climate state
– GCMs
– last millenium
– volcanic eruptions
– last glacial maximum data
– last glacial maximum models
– proxy data from millions of years ago…
It scores each approach on:
-similar climate base state
-similar feedbacks and timescales
– near equilibrium state
– most uncertanties considered
– quality/number of observations
– uncertainty in forcing
– confidence from multiple estimates
– constraint on upper bound
– overall confidence
It has an easily digestible summary graphic showing sensitivity and ranges for each approach. Likely climate sensitivity is 3C (+/-1C). (Suggested reading: Mark Lynas “Six Degrees” chapters 2C and 3C for potential impacts. The assumption by many posters that no negative impacts will accrue from such changes is optimistic at best.)
On reading this, I had a picture of a king, drawn by Bulwer, standing on the sand commanding the tide. YCMTSU!
At what point did British academics turn bat-sh*t crazy? When I was in uni, we had a certain reverence for the Brits who came over – their undergrad and pre-uni ed seem somewhat more disciplined and focused than what we Canucks were used to. Current observation tends to suggest that’s pretty much evaporated…
Also read: Your Tax dollars at work, US Fish Wildlife Service issues über alarmist report.
http://www.heliogenic.net/2010/09/30/your-tax-dollars-at-work-u-s-fish-wildlife-service-issues-uber-alarmist-report/
global sea levels some 6.6 to 9.4 metres
With a little dredging that would make Exeter a sea port. Does anyone wonder what 3 degrees might accomplish?
“I presume the sea level rise of 6 – 9 cm a year is a journalistic slip up. In the paper they say sea level is
“rising some 6–9 mm a−1 (Kopp et al., 2009) – at least double the current global average.” so I don’t think it’s fair to criticise/ridicule Turney on those grounds.”
Has a correction been issued ?
Am I reasonable to assume that Dr Turney reads his own glowing press ?
IS saying one thing to professionals and then another to the public at large
a strategy or an error ?
Unless a correction has been released I assume the former.
RE: King Cnut
Henry of Huntingdon, the 12th-century chronicler, tells how Cnut set his throne by the sea shore and commanded the tide to halt and not wet his feet and robes; but the tide failed to stop. According to Henry, Cnut leapt backwards and said “Let all men know how empty and worthless is the power of kings, for there is none worthy of the name, but He whom heaven, earth, and sea obey by eternal laws.” He then hung his gold crown on a crucifix, and never wore it again.
Ammonite says:
October 1, 2010 at 5:27 pm
Whatever the shortcomings or otherwise of the abovementioned study, there is a welter of information indicating a doubling of CO2 will likely lead to a global average temperature increase in excess of 2C. Please read a review of various approaches by Knutti and Hegerl 2008 at http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf.
An “interesting” paper. Based on my own, admittedly brief, perusal of it, I’d have to say that the climate sensitivity to a doubling of atmospheric CO2 could be 3C… or it could be a bologna sandwich. I rate it a pick’em.
This is more “science by press release”. I see nothing in the abstract to support the claim of the press release, that the seas will rise significantly more than previously thought.
BS seeking funding.
David Wendt,
even if I accepted your “doubling increases 2 centigrade” theory; two piddling centigrade will make no darn difference whatsoever.
So let me get this straight… In the last interglacial, all on its own and without the help of people making CO2, the planet got 5 C hotter than now, then plunged back into ice. And during this interglacial, even though we are approaching the end of it, and are several degrees cooler than then; warming is unprecedented and it’s our fault? And the answer is to reduce CO2 production? Because that was involved how last time?
Something is not adding up here for me…
A disclaimer is required. That no science was used in the production of this (sciency )product. On reflection, as a WUWT contributer suggested weeks ago, the 1st rank of AWG shills are in full retreat. To cover their retreat they encourage the 2nd raters and useful idiots to publish in support of the great cause.Hence strange claims such as this.
Can we fix the sun, so that it doesn’t interfere with our temperature too? Maybe a big blanket to block the sun out so we can be freezed down to -15 degrees like that new planet in the Goldilocks zone.
Paul Coppin says:
October 1, 2010 at 5:42 pm
At what point did British academics turn bat-sh*t crazy? When I was in uni, we had a certain reverence for the Brits who came over – their undergrad and pre-uni ed seem somewhat more disciplined and focused than what we Canucks were used to. Current observation tends to suggest that’s pretty much evaporated…
I ask myself the same question. When I did my degree (in the UK) it took considerable hard work to achieve a II.I degree classification. Relatively few people got them.
Now I find that my degree has been seriously devalued. More than 50% of degrees are now II.I classification – because industry wanted more II.I material, so what did they do? they lowered the bar to generate more of them!
Everwhere I look in the UK university system I see the same lowering of standards.
Truly sad.
Many critical comments here today. If all any of us read was the press release, they are most deserving. I looked the abstract up, a copy of which is below. Funny thing this, take the title away and it sounds like a different paper. (which is behind a pay wall)
Does the Agulhas Current amplify global temperatures during super-interglacials?
“Keywords:
* abrupt future climate change;
* El Niño–Southern Oscillation (ENSO);
* Southern Ocean;
* Southern Hemisphere westerlies;
* thermohaline circulation
Abstract
Future projections of climate suggest our planet is moving into a ‘super-interglacial’. Here we report a global synthesis of ice, marine and terrestrial data from a recent palaeoclimate equivalent, the Last Interglacial (ca. 130–116 ka ago). Our analysis suggests global temperatures were on average ∼1.5°C higher than today (relative to the AD 1961–1990 period). Intriguingly, we identify several Indian Ocean Last Interglacial sequences that suggest persistent early warming, consistent with leakage of warm, saline waters from the Agulhas Current into the Atlantic, intensifying meridional ocean circulation and increasing global temperatures. This mechanism may have played a significant positive feedback role during super-interglacials and could become increasingly important in the future. These results provide an important insight into a future 2°C climate stabilisation scenario. Copyright © 2010 John Wiley & Sons, Ltd.”
I don’t think you people, including myself, were harsh enough. I just hate it when the press release give a false impression of what the paper or abstract, has to say. It is junk like this that gives us earth scientists a bad name.
E.M.Smith says:
October 1, 2010 at 6:56 pm
So let me get this straight… In the last interglacial, all on its own and without the help of people making CO2, the planet got 5 C hotter than now, then plunged back into ice. And during this interglacial, even though we are approaching the end of it, and are several degrees cooler than then; warming is unprecedented and it’s our fault? And the answer is to reduce CO2 production? Because that was involved how last time?
Something is not adding up here for me…
========================
The only variable at this point is, the profit motive.
Just in time for Mexico!
How do these idiots expect anyone to believe their pure ranting BS. The more they predict doom and gloom and it’s worse than we thought they lose more supporters. They’d be better off just to STFU.
Is the University of Exeter the new East Anglia?
It seems the global warming debate on blogs like this now boil down to a partisan popularity contest. Meanwhile the world’s major Scientific Bodies still believe Global Warming is a dangerous reality as much as they did before “climategate.” Imperfect as they are, I’ll take “eco-fascist” scientific community over blog chest-thumping.
Of course, in the run-up to Copenhagen last year Dr. Stefan Rahmstorf of Germany’s Potsdam Institute declared that a two-meter sea-level rise [over the next 300 years] had now become almost ‘unstoppable’ unless we could extract enough CO2 from the atmosphere to cool the planet. I suppose we will all just ‘go with the flow,’ whatever that might be.
Just for reference; as the anthropogenic contribution to the CO2 in atmosphere is assumed to be on the order of 110 ppm, to anthropogenically double the current CO2 concentration in the atmosphere, we would need to find and burn almost four times as much fossil fuel as has already been done in the last 100 years. I assume that burning carbon recovered by plants from the atmosphere would not count.
Quote from the report
From their analysis, the scientists found 263 estimates of the conditions when sediments and ice were laid down during the Last Interglacial, allowing them to reconstruct past temperatures around the globe. To compare the reconstructed estimates with today, they took the Last Interglacial values away from modern temperatures averaged over the period 1961 to 1990.
unquote
So they now require to upgrade a 1,000 met stations, when this guy has resolved global climate with 263 estimates. So clearly current efforts are total overkill (snip) sorry sensitive word