This also reconfirms the unique nature of the Holocene. Of several temperature run ups, this is the only one that suddenly became stable at the peak no less. It made sense for it to perhaps stabilize part way up this curve but it takes something extraordinary for this to occur the way it did. Its two degree variability is confirmed across the entirety of the data, so the two degree variability of the Holocene represents a continuance.
As I have previously posted this is caused by the elimination of the Northern Ice Cap by the thirty degree shift of the crust. If you have not, please read my posts.
Two other factors need to be now considered. These peaks and their shapes are conforming even to the pair of secondary peaks. This powerfully suggests a cosmological explanation, certainly for the peaks. They demonstrate our expectations for a fairly fast pass through a star system that we are orbiting. The secondary highs do not, but may show high ultra violet radiation sources been passed through or even incoming material that heats up the sun.
The take home message is that this is not random. And since we are not now in close orbit of our parent star, when that happens, our climate will get ten degrees warmer. It will be well forested in the Arctic and a lot of that Antarctic ice will melt. It will last for ten to twenty thousands of years while the effects wear off. The actual transit and build up will be fairly quick. There is a good chance that all the polar ice will actually be melted before the cold begins to settle back in.
It is still a good plan. We have swapped ten thousand years of good weather and one hundred thousand years of very bad for one hundred thousand years of very good weather and ten thousand years of very hot weather.
The second factor is that the scale is flawed as expected. It tends to shrink as you go back in time and variation progressively wrecks accuracy. The current scale is the best estimate. If the peaks are associated with stellar events the actual scale could be as much as one million years long with a solar orbit approaching 180,000 years. We could also be over estimating the more recent layering of the ice.
Using the peaks as fixed points, it should be possible to make a tentative match to a putative orbit and take it from there.
Ice Core Evidence for Global Warming - a sceptical/skeptical view
But, here they are:
An Excel spreadsheet and graph of the data can be downloaded from here.If one sits down to look at the curves, a few things are apparent:
1. Four times in the period, (ie, roughly every 100,000 years) the temperature has quickly shot up to 2°C - 3°C above today's and then slowly slipped back to about 8°C below today's temperature. It looks as though the Earth's complex, non-linear climate system has two stable states and flops rhythmically from one to the other.
2. We are currently hovering near the top of a cycle and an ice-age seems to be due. However, comparing today's position with the 4 previous peaks suggests that the temperature should have reached 2°C or more some 10,000 years ago, but it hasn't. If anything, the world is now somewhat colder than we might expect.
3. CO2 and temperature track each other well. When one goes up, so does the other and conversely. They show such a strong correlation that one might suspect they are causally connected.
5. One explanation might be: when the world gets warmer, the oceans expel CO2 and, some hundreds to thousands of years later, the gas concentration rises. When the world get colder the oceans absorb CO2 and, some time later, the concentration falls. For some reason, when the temperature is rising, CO2 tracks quicker than when the temperature is falling.
7. In an area of science where experiments are hard to do, nature has given us 4 repetitions. The Vostock core clearly shows that when the temperature reaches 2°C a mechanism kicks in which sets the temperature falling again and initiates an ice-age. Since this mechanism has repeatedly worked well after 100,000 years of disuse, it seems to be robust.
8. Since the Industrial Revolution, man has contributed increasing amounts of CO2 and other greenhouse gasses to the atmosphere. It is said that these extra greenhouse gasses will change the climate cycle and that this time the temperature will climb far above the historical maximum, plunging the world into disaster.
9. There is about 800 B tonnes of CO2 in the atmosphere and human activities release another 27 B tonnes per year, or 3% of the total . CO2 in the air dissolves in the oceans and there is a lot more in the oceans than there is in the atmosphere. CO2 in the oceans slowly forms limestones, chalk and other rocks. More than 100 times the amount of CO2 in the atmosphere is locked up in these stones (The White Cliffs of Dover are largely CO2). But how much goes where and how long it stays there is not well understood. (See 'non-linear' in para 1). Even if one accepts that man is contributing large amounts of CO2 to the atmosphere, it will dissolve in the sea and then turn to limestone without any help from us.
10. If we consider all greenhouse gasses, not just CO2, the most important by far is water vapour, which contributes 36% of the total effect. Short of wrapping all the oceans in plastic sheet, we can't do much about that.
12. A fact that is often overlooked is that the amount of heat radiated by the earth into space varies as the fourth power of the absolute temperature. That is, if the average temperature of the atmosphere rises from 20C to 21C (293K to 294K or .3%), the radiated energy increases by 1.4%. This fourth power law has a strongly stabilising effect on global temperature.
13. It may be true that this small amount of extra greenhouse gas will trigger run-away global warming, but it is hard to find solid evidence for it in the historical record. What evidence there is must come from models of the way the climate works. But models of such complicated mechanisms as the climate are notoriously unreliable until they have been refined and rigorously checked against the historical evidence. Which has not yet happened.13. I am not a climatologist, but there is a solid looking review paper here. There is a scientific review of Al Gore's film here.
Natural global warming seems to be expected about now in the cycle, but I'm sceptical/skeptical about man-made warming.
If the science is hard to understand, the politics is easy. The 'man-made CO2 calamity' gives the developed nations a wonderful stick with which to beat the emerging superpowers of India and China.
If the west can persuade them that they have a moral duty to clean up their industries, substantial extra costs are imposed on them which will do something to offset the west's higher wages.
On the campaign level in the west, things work as usual in practical politics. Here is one of several accounts by scientists who changed their views about global warming, from
http://www.canadafreepress.com/2007/global-warming051607.htm "I was on that gravy train, making a high wage in a science job that would not have existed if we didn't believe carbon emissions caused global warming. And so were lots of people around me; and there were international conferences full of such people. And we had political support, the ear of government, big budgets, and we felt fairly important and useful (well, I did anyway). It was great. We were working to save the planet! But starting in about 2000, the last three of the four pieces of evidence outlined above fell away or reversed. The pre-2000 ice core data was the central evidence for believing that atmospheric carbon caused temperature increases. The new ice core data shows that past warmings were *not* initially caused by rises in atmospheric carbon, and says nothing about the strength of any amplification. This piece of evidence casts reasonable doubt that atmospheric carbon had any role in past warmings, while still allowing the possibility that it had a supporting role," he added. "Unfortunately politics and science have become even more entangled. The science of global warming has become a partisan political issue, so positions become more entrenched. Politicians and the public prefer simple and less-nuanced messages. At the moment the political climate strongly supports carbon emissions as the cause of global warming, to the point of sometimes rubbishing or silencing critics."