March 13, 2015
Chinese oil corporation: Same climate forces at work 1.4 billion years ago
A new study, conducted by scientists at the China National Petroleum Corporation, has found that the same climate forces at work today were also around 1.4 billion years ago – suggesting that current warming observations may be partially due to Earth’s natural climate rhythms.Published in the Proceedings of the National Academy of Sciences journal, the study is based on geological evidence and it found that Earth’s climate is significantly affected by how our planet orbits the Sun, also known as orbital forcing of climate change.
"This study helps us understand how past climate changes have affected Earth geologically and biologically,” said study author Donald Canfield, a professor at Nordic Center for Earth Evolution, University of Southern Denmark.
It's sedimentary, my dear Watson
The study was based on 1.4 billion-year-old sediments from the Xiamaling Formation in China. The sediments were analyzed and the results revealed how layers of organic material changed over time. These changes were attributed to cyclical changes in wind patterns, rain fall, and ocean circulations. The team said these results imply orbital forcing of climate change.
Climate is impacted by fluctuations known as Milankovich cycles that occur every 20,000, 40,000 and 100,000 years. Devised by Serbian geophysicist and astronomer Milutin Milanković, these cycles are driven by Earth’s eccentricity, axial tilt and orbit. During the last 1 million years, the cycles have triggered ice ages every 100,000 years, and currently – we are in the midst of a warming period that has lasted 11,000 years thus far, the study team said.
"Earth's climate history is complex. With this research we can show that cycles like the Milankovich cycles were at play 1.4 billion years ago - a period, we know only very little about,” Canfield said. "This research will also help us understand how Milankovitch cyclicity ultimately controls climate change on Earth."
In the other corner: Iceland rising
While the China National Petroleum Corporation-backed study may throw a bit of cold water on the idea of man-made global warming (maybe not), a different study published last month found that Iceland is actually rising as a result of unprecedented melting.
Gigantic sheets of ice hundreds of feet thick push down on the land below them, but when that ice melts, it allows the land to rise up. The researchers behind this study noted that the effect is more exaggerated on Iceland because the island nation sits atop a highly-liquefied mantle section of Earth.
The study concluded that areas of Iceland as rising around 1.4 inches per year.