In a new study that may greatly add to our understanding of the drivers behind climate change, researchers from Lund University in Sweden claim to have accurately reconstructed solar activity levels during the last ice age. By analyzing trace elements in ice core samples in Greenland and cave mineral formations in China, the scientists assert that regional climate is more influenced by the sun than previously thought.
The effect of the sun on natural climate change has been one of constant debate, and its degree of influence varies dependent upon the climate modelling used. However, this recent study by Lund University may suggest that direct solar energy input affects parts of the atmosphere which then indirectly changes atmospheric circulation, resulting in increases or decreases in temperature over certain regions.
According to the researchers, a measurable variance in solar activity during the last glacial maximum (22,500 - 10,000 years ago) resulted in increased winter precipitation during periods of low solar activity. The team claims that these results may explain the positive correlations between their solar activity reconstruction and the study of indicator isotopes they used as a measure of historical precipitation temperatures in the examined ice cores.
"Reduced solar activity could lead to colder winters in Northern Europe. This is because the sun’s UV radiation affects the atmospheric circulation. Interestingly, the same processes lead to warmer winters in Greenland, with greater snowfall and more storms." said Dr said Raimund Muscheler, Lecturer in Quaternary Geology at Lund University. "The study also shows that the various solar processes need to be included in climate models in order to better predict future global and regional climate change."
Further to their theory, the researchers believe that changes in wind patterns resulted from alterations in received temperatures, suggesting that a top-down solar influence increased oceanic feedback and may have acted as an additional amplification mechanism. In other words, variations in solar radiation affected the atmosphere, altering the barometric pressure which, in turn, changed the prevailing wind patterns in the upper atmosphere.
In atmospheric physics parlance, these winds are known as eddy-driven jets and a high-pressure increase over the North Atlantic (as evidenced in today's climate) is often accompanied by a displacement to the south of these winds. This results in a negative effect on the North Atlantic Oscillation (the atmospheric pressure difference at sea level between the Icelandic low and the Azores high), which can produce colder winds and higher levels of snowfall.
As a result, the alteration of these winds changes the way in which heat is exchanged between the oceans and the atmosphere. In the Lund University reconstruction and modeling, evidence is shown that this particular effect was being exacerbated by the amount of solar energy striking the Earth's atmosphere in direct relationship to the activity of the sun.
"The study shows an unexpected link between solar activity and climate change. It shows both that changes in solar activity are nothing new and that solar activity influences the climate, especially on a regional level," said Dr Muscheler. "Understanding these processes helps us to better forecast the climate in certain regions."
The upshot of all this is that the team claims that these results provide a testable theory for an alteration of current orbital sun/climate hypotheses, as the position and strength of the eddy driven jet is, along with other influences, proven to be related to orbital forcing (the effect on climate of slow changes in the tilt of the Earth's axis and shape of the orbit).
As such, the scientists believe that this indicates that changes in solar activity influence the climate, particularly at a regional level, and that the variations in the sun’s output also influences the climate irrespective of whether the planet is largely mild as it is today, or in the grip of an ice age.
The results of this research have been published in the journal Nature Geoscience
Source: Lund University
But by all means, keep buying your Priuses. That lithium comes from magic fairies, right?
It's almost as if someone profits from environmental buzzwords and the general public's scientific complacency...
Up until very recently, the idea that solar variability drove climate was taken as a given. It was only in recent decades that there was a claimed "deviation" between climate and the solar cycles.
But as we have been finding out, more and more over the last 2+ years, is that much of this "deviation" could be due to the very "adjustments" that have been made to the temperature data, ostensibly to correct for various kinds of measurement errors.
Really? you're only starting to think that now? The earth has been warming since the ice age, it doesn't worry me. What does worry me is the destruction and polution of the planet.
If, instead of leaping to conclusions, people actually read the above article they would find that it is mainly about regional climates being affected by changes to wind and ocean circulations brought on by variations in the sun's output. It adds that it does have some overall influence on how the Milankowiec cycles operate, though they themselves are miniscule in their influence. That is way science works, extending our knowledge. Of course the sun affects earth's climate, it is the source of all our energy, so how could it do otherwise? What we do not know is just how valid this report is. For that we are going to need others to repeat the work. That too is also the way science works.
It is questionable as to who the "morons" referred to in the above comments really are when we have severe droughts, violent flooding and increased storm intensities, entirely in line with climate model predictions, yet the topic can still generate some, if not all, of the above comments.
We know that we are headed for at least 3 degrees C rise in global temperatures, which is going to have dramatic effects, not least of which will be in agriculture. One would have thought that the prospect of starving to death would be sufficiently worrying to persuade people to question the MSM's take on the matter, especially its need for advertising revenue as dictated by the fossil fuel industry. Isn't it in fact moronic not to explore the matter sensibly, instead of simply parroting what FOX News and the like have to say about it?
Anyone so inclined could do worse than visit skepticalscience.com, where they will find a load of information on the topic. It is also worth watching Admiral Titley's TED talk at: www.youtube.com/watch?v=7udNMqRmqV8 to see just how concerned the American navy is about climate change. The navy cannot afford to simply dismiss the notion that climate change is all a hoax the way above commenters do because they have some very real problems coping with sea-level rise and what it is going to do to their ports and their vessels' abilities to use them. The insurance industry is similarly constrained because climate change is going to cost them a lot of money, as can be seen in this article: http://www.pwc.co.uk/sustainability-climate-change/issues/insurance-leaders-respond-to-climate-change.jhtml
There can be no denying that the greenhouse effect is real. We know that without it, the earth would be just under 35 C cooler than it is today and we would not exist. There can be no denying that CO2 is a greenhouse gas and there can be no denying that it is very long-lived in the atmosphere. There can be no denying that even if we stopped pumping the stuff into the atmosphere today, we are destined to at least a 3 C rise since the start of the Industrial Revolution with a business as usual approach. There can be no denying that we as a species have a problem, unless one cannot be bothered to study just how much harm that is going to create, of course.
If it weren't so sad, one could see many of the above comments as a case of turkeys voting for Christmas, or Thanksgiving, depending on which side of the pond one is.