Three fascinating papers were published in Science (Vol 310, 25th November 2005) last week on climate change and the relationship between carbon dioxide, methane and nitrous oxide levels and temperature over the last 650,000 years.
They report on new findings from the European Project for Ice Coring in the Antartica.
A graph in the 'perspectives section' by Brook (pg 1286) summarizes the findings,
view image (70 kbs).
The data tells me that:
1. The greenhouse gases are at higher levels now than they have been over the last 650,000 years.
2. Carbon dioxide levels correlated with temperature and have peak during previous interglacial warm periods just below 300ppm, view image (120 kbs).
3. In the past, increases in atmospheric carbon dioxide levels have tended to follow, rather than preceded, rises in temperature.
4. We are currently in an interglacial warm period and these periods tend to be followed by very cold periods.
I find the graphs fascinating.
While atmospheric carbon dioxide levels have clearly fluctuated with temperature in the past, they have tended to lag behind temperature. This doesn't accord with the current perception - what is understood to be the current consensus which is that carbon dioxide drives temperature?
I find the prospect of another ice age really scary. The graphs suggest to me that one is imminent - like in the next few hundred or thousand years? However, greenhouses gases have never been so high.
It is perhaps interesting to ponder .... If we were able to influence climate in a predictable way, and if we could delay indefinitely the onset of the next ice age, should we?
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Many, many thanks to the reader of this blog who sent me copies of the papers. There has been some discussion of the papers at the Real Climate blog, http://www.realclimate.org/index.php?p=221&lp_lang_view=en .
Louis - Again you are confusing the Enhanced Greenhouse effect causing warming of the atmosphere which is scientifically correct and provable with the results of that warming which at the moment is speculation. Alluding to religion seems to be a standard tactic of global warming skeptics however is more akin to your steadfast faith in the skeptic arguments that fly in the face of even the most basic high school physics.
If global warming produces an influx of fresh water into the Northern Atlantic that shuts down the Atlantic current then the result of warming could well be cooling of Northern Europe that is warmed by warm air transported from the tropics. The Younger Dryas was perhaps caused by this very thing.
Nobody has any idea other than informed guesses what the results of AGW might be. A blind faith that the results will be benign is yet another reason to call your side of the argument a religion.
What utter utter arrant nonsense.
"every change" - says who?
Climate change has been well quantified except some aren't up to understanding the basics as the folly of their blog rhetoric displays. Wouldn't pass year one physics or class one, year one stats for that matter.
and who are "global warmers", and "who" is saying what?
The impact of the thermohaline circulation on European climate is well known. How much do we have to have to play with salinity content to destablise it, is an interesting question. If you did interfere with it yes would would have some regional cooling. If one wanted to get some resolution on new scientific developments check the latest realclimate and Nature paper and think before spruiking. All may not be as it seems.
Richard,
I think Professor Stott has summarised it brilliantly on his environspin site which I also duplicated on my blog.
When the theory of global warming purports to explain every observed climatic change, then surely we have left science an entered into the realm of religion. Global warmers are now insisting that if the weather gets colder, its due to global warming.
As for the assertion of more severe climate change, no one has been able to quantify climate change, so how one can scientifically discern such proposals will remain problematical for a long time.
hmmm - the problem is Richard that the press reporting of the issue is over half from sceptics - but very little published in the literature against. So how much debate is "healthy" really. How much of this paralyses our ability for any rational thought or action on the issue.
Plus it has become allied with "green politics". If you argue for AGW you must also be anti-capitalism, anti-business, anti-GM and eat lentils. Why so? Whatever happened to clear independent thinking.
Further accessing the literature is somewhat difficult (hence realclimate exists to counter a bit).
Understanding the literature is also difficult.
i.e. it's complex stuff.
Most of us don't even properly understand the CO2 physics, role with respect to water vapour and why greenhouse is even a bad name. So not even at the basics of understanding. Not being arrogant - it's not that simple in the end. See Louis blog as a classic case of missing the entire point and the danger of assuming that you've discovered something fundamental that nobody else has ever thought of. Frequency probably depends on level of ego. New insight happens - but not often.
Similarly it's amazing to think that people would not assume the BoM would not have a high quality station network and these data are the ones they use for climate change studies - not cities with possible UHIs.
And in cities maybe the UHI effect may be overstated as the met stations are often in leafy green park settings. Might even balance out the UHI effect somewhat. Not saying this always happens.
Louis states that the theory of warming cannot be falsified, Really! should, we not say that the probably that warming is true and that it is human induced climate change is such that it is very unlikely that alternative explanations can account for the very large body of observations as well as the current theory.
Quantum mechanics is a case of an elegant and very well tested theory where science is still trying to prove it wrong with little success in the last 25 years! Climate change science is the same if you put up a good body of evidence it will be accepted as small part of the knowledge structure, but you need a lot of strong evidence to overturn strong theory and I do not see nearly enough contrary evidence in the scientific literature to overwhelm the current theory, however there is plenty of healthy debate.
Science is not religeon but an exercise in reducing uncertainty. It is the deep greens, the religeous and those with large economic intrests who seem to hold the most dogmatic views of all.
Jen - the assertion that all climate data are unavailable is simply incorrect.
For a small fee anyone can acquire the Bureau's Australian raw data. Given complaints about the Bureau's analysed data sets (Warwick Hughes) I would assume anyone would want the raw data and not processed data.
You could start there, on quite a large data sets, and test if the Australian warming arguments stack up.
I see any refusal to at least start there as rhetorical bluster and not fair dinkum, particularly if one is asserting people are "crooks". Strong words.
Perhaps after demonstrating some "credentials" with local data Jones, Hansen et al might be more forthcoming with raw data from other countries. One can imagine they may be harried by many interesting and colourful internet travellers for such data. Given the size of the data is mnay tens of gigabytes I can imagine it's not the sort of thing you would download over dinner.
Of course an introductory statistics course might also be useful, particularly if you need to understand complexities such as the difference between running means and simple single arithmetic means.
Oh for heavens sake read it !!
Phil Done,
You posted a reference to Greenhouses above, in which convection is proposed as the primary greenhouse mechanism.
You just shot your own foot.
I suspect you do not read your posts which you cut and paste here.
ENDER,
You cannot even spell,