New Model Spanning 24,000 Years Shows Warming is Underestimated

New Model Spanning 24,000 Years Shows Warming is Underestimated

A new map published in Nature models how Earth's climate has changed over 24,000 years. By comparing sediment cores, which record temperatures over thousands of years, researchers were able to get a sense of global temperature records.

Why This Matters

The new map, alongside new high resolution satellite images from NASA, gives a sense of the scale and magnitude of contemporary global warming. Guidelines and policies in the Paris Agreement aimed to limit warming to 2.7 degrees Celsius above pre-industrial levels -- a temperature increase roughly equivalent to the warming that took place between 12,000 and 200 years ago. Scientists warn that blowing past the 1.5 degree goal would cause drastic and widespread changes to the world as we know it -- coral reefs would die, storms and droughts would become more severe, and coastal cities and island nations would flood.

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Refuting Climate Skepticism

Deniers of climate change claim global warming is not as severe as scientists make it out to be, clinging to the fact that 6,000 years ago, glaciers receded while the earth cooled as evidence. As Popular Science put it, "How can the greenhouse effect be so important for global warming if greenhouse gases increased during the Holocene at the same time as global temperatures declined?"

The new map reinforces a paper published earlier this year that refutes the argument of deniers and asserts climate modeling has been problematic -- that Earth wasn't actually cooling after the glaciers melted. By studying sediment cores, which were dominant in the Northern Hemisphere, researchers found that previous models were incorrect. Even using different methods of research, both the map and the paper generated the same result -- that Earth's climate was 10 degrees Fahrenheit colder prior to glacier retreat and has been warming since.

Matthew Osman, a climatologist at the University of Arizona and the study's lead author, told Popular Science that even just two to three degrees of warming would mean "essentially a large fraction of these interglacial changes occurring in a really, really short amount of time. And that should be something that I think concerns everybody."

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