Some 3.8 billion years ago was a mystery that scientists have long attempted to solve.
Way back then, the Earth was a completely different place, and so was the solar system. The sun shined with less luminescence – as much as 30 percent weaker – which meant the Earth should have been really cold. So cold, in fact, that liquid water would not have existed.
11 Year Solar Cycle
But the geologic record shows that water was, indeed, present and provided the foundation for the proverbial “primordial soup” that gave rise to life. How come? This is what’s called the “faint young sun problem.”
There are many theories… Clearly more went on than we know.
Why does this matter to modern day climate change?
“One thing that paleoclimate research definitely does do is to put modern day climate change into perspective,” Geochemist James Kasting of Penn State University points out.
The disappearance of glaciers goes hand in hand with warming temperatures. But it turns out that the process may be more complicated than rising CO2 levels in the atmosphere. For insight, we look to the past.
Dr. M. Vizcaino Trueba
What kept the ice sheets at bay has been explored in a recent paper in the journal Paleoceanography by UC Berkeley geographer M. Vizcaino and colleagues.
The scientists believe that during the Pliocene, a permanent “El Nino state” may have been taking place.
In a permanent El Nino, sea temperatures remain constant across the Pacific, and the cold water upwelling, known poetically as the “cold tongue” goes limp. As a result, warmer air invades North America, Greenland, and part of Eurasia around the Black Sea, raising temperatures by as much as 9 degrees Fahrenheit. Conversely, temperatures become the coolest in much of northeast Eurasia. This overlaps nicely with where glaciers would otherwise exist, northeast Eurasia being glacier-free. The researchers write:
The climate reorganization caused by a permanent El Nino results in temperature anomalies over the northern high latitudes remarkably coincident with known locations of ice sheet growth.
The “cold tongue” could be more important than we thought.
Please read the article in full here: http://www.terradaily.com/reports/A_History_Of_Climate_Change_999.html
Source: Terra Daily – by Staff Writers – Moffett Field CA (SPX) Jun 22, 2010
Photo Credit: Steele Hill, SOHO, NASA/ESA
