The gusting westerly winds that dominate the climate in central Asia, setting the pattern of dryness and location of central Asian deserts, have blown mostly unchanged for 42 million years. (more…)
A new study of sharks that lived in warm Arctic waters millions of years ago suggests that some shark species could handle the falling Arctic salinity that may come with rising temperatures.
The Arctic today is best known for its tundra and polar bear population, but roughly 38 to 53 million years ago during the Eocene epoch, the Arctic was like a huge temperate forest with brackish water, home to a variety of animal life, including ancestors of tapirs, hippo-like creatures, crocodiles and giant tortoises. Much of what is known about the region during this period comes from well-documented terrestrial deposits. Marine records have been harder to come by. (more…)
Dissolution or creation of huge gypsum deposits changed sulfate content of the oceans
Scientists have discovered a potential cause of Earth’s “icehouse climate” cooling trend of the past 45 million years. It has everything to do with the chemistry of the world’s oceans.
“Seawater chemistry is characterized by long phases of stability, which are interrupted by short intervals of rapid change,” says geoscientist Ulrich Wortmann of the University of Toronto, lead author of a paper reporting the results and published this week in the journal Science.
“We’ve established a new framework that helps us better interpret evolutionary trends and climate change over long periods of time. The study focuses on the past 130 million years, but similar interactions have likely occurred through the past 500 million years.” (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…)
