It’s no secret that volcanic eruptions can cool the planet by spewing ash and droplets of sulfuric acid into the atmosphere that obscure the sun. Now researchers at Germany’s GEOMAR Helmholtz Centre for Ocean Research Kiel and Harvard University have found evidence that suggest the reverse could also be true. The researchers have discovered a strong historical link between global temperature increases and increases in volcanic activity.
Using observations of ash layers in cores taken from the seafloor around the Pacific region, the researchers reconstructed the history of volcanic eruptions for the past one million years. When they compared this data with the climate history, they found that periods of fast, global temperature increases and associated ice melting were followed with periods of high volcanic activity.
Using geological computer models, the researchers have come up with a possible explanation for the link.
"In times of global warming, the glaciers are melting on the continents relatively quickly,” says Dr. Marion Jegen, a geophysicist from GEOMAR. “At the same time the sea level rises. The weight on the continents decreases, while the weight on the oceanic tectonic plates increases. Thus, the stress changes within in the earth to open more routes for ascending magma."
Because the rate of global cooling at the end of warm phases is much slower compared to the rate of warming at the beginning of such phases, there are less dramatic stress changes and less volcanic activity during these times.
"If you follow the natural climate cycles, we are currently at the end of a really warm phase,” says Dr. Steffen Kutterolf, the lead author of the study. “Therefore, things are volcanically quieter now.”
Kutterolf adds that since the impact from man-made warming is still unclear, the next step will be to investigate shorter-term historical variations in an effort to understand the implications for the present day.
The results of the team’s study are published in the journal Geology.
Source: GEOMAR
It is not important who, what or why the planet is warming. I.e. it is the ‘GW’ in AGW is what matters, not the ‘A.’ What is important is that the current warming is headed for conditions by mid-century that can only be described as dire. We know that the warming is not going to stop by then either, no matter what we do, other than perhaps full-blown nuclear war. A cure worse than the disease if ever there were one. So we know that our families, indeed all future generations, are in for a bleak time of it. What we can also be fairly sure of is that at some point society will not withstand the stress the rising temperatures will create. We can be fairly certain that drought will be a common feature of the future climate and food production will be severely curtailed as a result. Parts of the world have already experienced food riots. We can only expect there to be more of them, many more. Seeing as supermarkets only carry around 3 day’s supply, how long will it be before the mob takes over? From there, we can expect fuel deliveries to stop and seeing as society relies heavily on transport to function the descent into chaos will be rapid. Do we really want our children and grandchildren to have to endure such privations?
Future generations will look back on this generation in particular and wonder why we were so selfish not to act to ameliorate the harm that all the science is warning us of. Was the captain of the Titanic wrong to at least try to avoid the iceberg because? It was, after all, not man-made i.e. not anthropogenic in origin? That might sound stupid, but surely arguing about the ‘A’ in AGW is just as stupid. The Titanic disaster only killed about 1500 people. GW, regardless of its cause, is on target to kill many orders of magnitude more. Their blood will be posthumously on our hands unless we do more than only give lip service to taking any action. And all the while the fossil fuel industry executives just keep reaping in their profits. One can only assume that they don’t have any children, or if they do, they don’t care about them. Strange how the teaching of ‘Do unto others ...’ has be so completely forgotten by those that do most to try and convince us that they are Christians, and some indeed to convince us that their nation is blessed by God.
Anyone expected to be alive by mid-century, or is the guardian of someone who will, would do well to watch the 2012 Cabot Annual Lecture (available on Youtube). Perhaps after watching it, the denialati might be persuaded to keep their mouths shut and their minds open. They are all in the same boat as the rest of us and no amount of wealth is going to buy them forgiveness, or even shelter from the forthcoming storm.
There is a force much larger and more powerful, than we are giving to the human race, which can influence GW or global cooling - the Sun.
Wasn't there a recent report that there was GW on Venus, and Mars? I understand humans think their influence is great, . . . but really?!?