Just how cold was the Ice Age? New study finds the temperature

Researchers figure out the average temperatures of the last ice age on Earth.

icebergs

Icebergs.

Credit: Pixabay
  • A new study analyzes fossil data to find the average temperatures during the last Ice Age.
  • This period of time, about 20,000 years ago, had the average temperature of about 46 degrees Fahrenheit (7.8 C).
  • The study has implications for understanding climate change.


How cold was the Ice Age? While one can imagine layers of ice covering everything around the world, that's not exactly what happened. In fact, researchers identified the temperature of the Last Glacial Maximum, from about 20,000 ago, to be about 46 degrees Fahrenheit (7.8 C).

This, of course, was the average global temperature – not the extent of how cold it really got in some places. The Last Glacial Maximum (LGM) was a very chilly period, when glaciers covered about half of North and South Americas, as well as Europe and parts of Asia. Overall, the new paper found that the world's temperatures were about 11 degrees Fahrenheit or 6 degrees Celsius less warm than today. If you're comparing, the average global temperature was 14 C (57 F) in the 20th century.

The study's lead author, Jessica Tierney, associate professor at the University of Arizona Department of Geosciences, addressed that this may not sound like a big deal to some but was, in fact, monumental.

"In your own personal experience that might not sound like a big difference, but, in fact, it's a huge change," explained Tierney. "In North America and Europe, the most northern parts were covered in ice and were extremely cold. Even here in Arizona, there was big cooling. But the biggest cooling was in high latitudes, such as the Arctic, where it was about 14 C (25 F) colder than today."

This corresponds to climate change models, which show that high latitudes get warmer at a faster rate than low latitudes. This means, according to projections, that this process of "polar amplification" will make it warmer and warmer over areas like the Arctic which are more sensitive to climate change.

Surface air temperatures during the last ice age.

Credit: Jessica Tierney, University of Arizona

Tierney's team calculated that every time the amount of atmospheric carbon will double, global temperatures should go up by 3.4 C (6.1 F). Carbon levels during the Ice Age were about 180 parts per million, then rose to about 280 parts per million during the Industrial Revolution, and have by now reached 415 parts per million.

How did the scientists reach their conclusions? The team used models that connected data from ocean plankton fossils to sea-surface temperatures. A technique called data assimilation, used in weather forecasting, was then employed to link the fossil data with climate model simulations of the LGM.

"What happens in a weather office is they measure the temperature, pressure, humidity and use these measurements to update a forecasting model and predict the weather," Tierney shared. "Here, we use the Boulder, Colorado-based National Center for Atmospheric Research climate model to produce a hindcast of the LGM, and then we update this hindcast with the actual data to predict what the climate was like."

The findings will help climate scientists evaluate how today's rising atmospheric levels of carbon dioxide influence the average temperatures around the world.

Co-authors of the new study also include professor Christopher Poulsen from the University of Michigan and postdoctoral researcher Jiang Zhu, now with the National Center for Atmospheric Research.

"Six degrees of global average cooling is enormous. The world would have looked much different during the last glacial maximum," said Poulsen, adding "The northern portions of North America, including here in Ann Arbor, Michigan, were covered by kilometers of ice."

You can read their paper published in Nature.


COVID-19 amplified America’s devastating health gap. Can we bridge it?

The COVID-19 pandemic is making health disparities in the United States crystal clear. It is a clarion call for health care systems to double their efforts in vulnerable communities.

Willie Mae Daniels makes melted cheese sandwiches with her granddaughter, Karyah Davis, 6, after being laid off from her job as a food service cashier at the University of Miami on March 17, 2020.

Credit: Joe Raedle/Getty Images
Sponsored by Northwell Health
  • The COVID-19 pandemic has exacerbated America's health disparities, widening the divide between the haves and have nots.
  • Studies show disparities in wealth, race, and online access have disproportionately harmed underserved U.S. communities during the pandemic.
  • To begin curing this social aliment, health systems like Northwell Health are establishing relationships of trust in these communities so that the post-COVID world looks different than the pre-COVID one.
Keep reading Show less

Mathematical model shows how the Nazis could have won WWII's Battle of Britain

With just a few strategical tweaks, the Nazis could have won one of World War II's most decisive battles.

Photo: Heinrich Hoffmann/ullstein bild via Getty Images
Politics & Current Affairs
  • The Battle of Britain is widely recognized as one of the most significant battles that occurred during World War II. It marked the first major victory of the Allied forces and shifted the tide of the war.
  • Historians, however, have long debated the deciding factor in the British victory and German defeat.
  • A new mathematical model took into account numerous alternative tactics that the German's could have made and found that just two tweaks stood between them and victory over Britain.
Keep reading Show less

The neoliberal era is ending. What comes next?

The next era in American history can look entirely different. It's up to us to choose.

Videos
  • The timeline of America post-WWII can be divided into two eras, according to author and law professor Ganesh Sitaraman: the liberal era which ran through the 1970s, and the current neoliberal era which began in the early 1980s. The latter promised a "more free society," but what we got instead was more inequality, less opportunity, and greater market consolidation.
  • "We've lived through a neoliberal era for the last 40 years, and that era is coming to an end," Sitaraman says, adding that the ideas and policies that defined the period are being challenged on various levels.
  • What comes next depends on if we take a proactive and democratic approach to shaping the economy, or if we simply react to and "deal with" market outcomes.

Keep reading Show less

10 ways to prepare for rise of intelligent machines – MIT study

A new MIT report proposes how humans should prepare for the age of automation and artificial intelligence.

An employee cleans around early test robot displays at the Akin Robotics factory on March 15, 2018 in Konya, Turkey.

Photo by Chris McGrath/Getty Images
Technology & Innovation
  • A new report by MIT experts proposes what humans should do to prepare for the age of automation.
  • The rise of intelligent machines is coming but it's important to resolve human issues first.
  • Improving economic inequality, skills training, and investment in innovation are necessary steps.
Keep reading Show less
Scroll down to load more…
Quantcast