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WASHINGTON — Guided by ocean plankton fossils and climate models, scientists have calculated just how cold it got on Earth during the depths of the last Ice Age, when immense ice sheets covered large parts of North America, South America, Europe and Asia.
The average global temperature during the period known as the Last Glacial Maximum from roughly 23,000 to 19,000 years ago was about 46 degrees Fahrenheit (7.8 degrees Celsius), some 13 degrees Fahrenheit (7 Celsius) colder than 2019, the researchers said on Wednesday.
Certain regions were much cooler than the global average, they found. The polar regions cooled far more than the tropics, with the Arctic region 25 degrees Fahrenheit (14 degree Celsius) colder than the global average.
The researchers made their calculations with the aid of chemical measurements on tiny fossils of zooplankton and the preserved structures of fats from other types of plankton that change in response to water temperature – what they called a “temperature proxy.”
This information was then plugged into climate model simulations to calculate average global temperatures.
“Past climates are the only information we have about what really happens when the Earth cools or warms to a large degree. So by studying them, we can better constrain what to expect in the future,” said University of Arizona paleoclimatologist Jessica Tierney, lead author of the research published in the journal Nature.
https://news.google.com/__i/rss/rd/articles/CBMib2h0dHBzOi8vbmF0aW9uYWxwb3N0LmNvbS9wbW4vZW52aXJvbm1lbnQtcG1uL2hvdy1sb3ctZGlkLWl0LWdvLXNjaWVudGlzdHMtY2FsY3VsYXRlLWVhcnRocy1pY2UtYWdlLXRlbXBlcmF0dXJlc9IBAA?oc=5
2020-08-26 20:05:19Z
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