AUSTIN, Texas — Researchers at The University of Texas at Austin have found that a well-known period of abrupt climate change 12,000 years ago occurred rapidly in northern latitudes but much more gradually in equatorial regions, a discovery that could prove important for understanding and responding to future climate change. (more…)
*New research reveals how the arrival of the first plants 470 million years ago triggered a series of ice ages. Led by the Universities of Exeter and Oxford, the study is published in Nature Geoscience.*
The team set out to identify the effects that the first land plants had on the climate during the Ordovician Period, which ended 444 million years ago. During this period the climate gradually cooled, leading to a series of ‘ice ages’. This global cooling was caused by a dramatic reduction in atmospheric carbon, which this research now suggests was triggered by the arrival of plants.
Among the first plants to grow on land were the ancestors of mosses that grow today. This study shows that they extracted minerals such as calcium, magnesium, phosphorus and iron from rocks in order to grow. In so doing, they caused chemical weathering of the Earth’s surface. This had a dramatic impact on the global carbon cycle and subsequently on the climate. It could also have led to a mass extinction of marine life. (more…)
A Yale University-led research team has found evidence that carbon dioxide levels in Earth’s atmosphere plunged prior to and during the initial icing of Antarctica, about 34 million years ago. The new findings provide further evidence of atmospheric carbon dioxide’s role as a major trigger of global climate change.
“CO2 is tracking global cooling at that time,” said Yale geochemist Mark Pagani, lead author of a paper published online Dec. 1 in the journal Science. “It’s important to demonstrate that there are obvious linkages between CO2 and climate change. It’s one more piece of evidence that CO2 is a primary lever on climate.” (more…)
SAN FRANCISCO — The northernmost mummified forest ever found in Canada is revealing how plants struggled to endure a long-ago global cooling.
Researchers believe the trees — buried by a landslide and exquisitely preserved 2 to 8 million years ago — will help them predict how today’s Arctic will respond to global warming.
They also suspect that many more mummified forests could emerge across North America as Arctic ice continues to melt. As the wood is exposed and begins to rot, it could release significant amounts of methane and carbon dioxide into the atmosphere — and actually boost global warming. (more…)
