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Kristin Hugo
By Kristin Hugo October 10, 2022

No, research doesn’t show the Earth was 2 degrees Celsius warmer 55,000 years ago

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  • Antarctic ice cores show that temperatures there were nearly 7 degrees Celsius colder in that region 55,000 years ago.

  • Even if it were true that the Earth was warmer then, it would not rebut human-caused climate change. The Earth goes through temperature cycles, but human-made climate change is accelerating that process. 

Former oil executive Dan Peña has made his stance on climate change clear. As far as he is concerned, it’s not an issue.

As evidence of why, in May 2021 Peña told an audience the story of a visit he and his wife made to Antarctica. Scientists were drilling ice core samples to determine former Earth temperatures, he said, and one scientist described to onlookers what those samples revealed.

"‘Fifty-five thousand years ago, the world was 2 degrees warmer Celsius than it is today,’" Peña said the scientist told him. "And I said, ‘Well, you mean the whole world?’ And he said, ‘Yes.’ ... In the cosmos of time, it’s not a fart in the wind. In the cosmos of time in the 13.8 billion years that we’ve been on this miserable planet, it’s not a fart in the wind." 

The Earth is about 4.54 billion years old, not 13.8 billion. The first life appeared about 3.7 billion years ago.

The video segment was filmed at an event hosted by London Real, a company that makes videos on self-improvement, business, finances and other topics. The notion that the Earth was 2 degrees Celsius warmer 55,000 years ago has been previously debunked by Climate Feedback, a scientific reference, but videos of Peña making this claim have continued to appear on social media including Facebook, Instagram and TikTok.

Some of these posts were flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Meta, which owns Facebook and Instagram.)

Teams of scientists do drill ice cores in Antarctica, including at the British Antarctic Survey and the National Science Foundation Ice Core Facility. As snow falls, it compresses, and in the Antarctic’s cold, it doesn’t thaw, even over hundreds of thousands of years. Scientists collect and study ice cores to discern information about temperatures as far back as 800,000 years ago. Tiny air bubbles trapped in the ice provide information about what the environment was like at the time, including carbon dioxide concentrations. 

Bethan Davies, a senior researcher at the School of Geography, Politics and Sociology at Newcastle University in England, told PolitiFact in an email that she knows of no reputable source that claims Earth temperatures were higher 55,000 years ago.

"It shows a solid misunderstanding of Earth’s palaeoclimate and the drivers of past temperature change," said Davies, who also runs, a website about the study of glaciation and the Antarctic.

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The temperature in one studied region of Antarctica was -35.6°C 55,000 years ago, according to data published in 2016 in the journal Proceedings of the National Academy of Sciences. It said that in 2006, the average temperature in that area of Antarctica was -28.7°C — that was about 6.9°C warmer than the temperature in that region 55,000 years ago. 

There is also data about the Northern Hemisphere going back 120,000 years that shows it was colder 55,000 years ago in Greenland, too. 

To visualize Earth’s climate 55,000 years ago, note that this was the time of wooly mammoths. This would have been during a period of slight warming compared with the rest of that glacial period, but it was not warmer than today, Davies says. 

There are periods in Earth’s history in which the planet was much warmer than today, or even too hot for humans to live.

For instance, 600 million to 800 million years ago, long before the dinosaurs, the global average temperature was 90° Fahrenheit (32°C) as opposed to the 20th-century global average, which was about 57° F (14°C) according to modern measurements by the National Oceanic and Atmospheric Administration. The global average of 2021 was 1.51°F (0.84° Celsius) warmer than that, according to NOAA’s 2021 report on average land and sea temperature.

However, that there have been gradual periods of warming in the past doesn’t mean that climate change is a hoax, normal, or safe.

Although the Earth’s temperature has fluctuated, both in deep time and over the last century, the speed at which the climate is changing affects "water, energy, transportation, wildlife, agriculture, ecosystems, and human health," according to NOAA. Even natural climate variations are disruptive, as temperatures, sea-level changes, and other phenomena result in changes to the atmosphere and weather, as well as extinctions of plants and animals. Human-driven change is of particular concern, though, as human activity is happening at rates the United Nations calls "unprecedented" and "irreversible" for centuries or millennia, too fast for the natural world and human society to safely adapt. 

Our ruling

A video circulating on Facebook showed Peña saying Antarctic ice cores show the Earth was 2 degrees Celsius warmer 55,000 years ago.

Scientific research looking at the Southern and Northern hemispheres shows that assertion is wrong. Although the planet’s temperatures have fluctuated over billions of years, research published in 2016 shows the Antarctic was 6.9°C colder compared with 2006, the most recent year for which ice core data has been collected.

We rate this claim False.  

Our Sources

Facebook post, Sept. 6, 2022

Facebook post, Dec. 13, 2018

Dan Peña, remarks posted April 24, 2021

Dan Peña, remarks archived May 27, 2019

Dan Peña, remarks posted December 14, 2018, home page, accessed September 18, 2022

University of Washington, "Scientists drill deep in Antarctic ice for clues to climate change," December 9, 2020

British Antarctic Survey, "Ice cores and climate change," June 30, 2022

United States Geological Survey, "National Science Foundation - Ice Core Facility," accessed September 18, 2022

Email interview with Bethan Davies, a senior researcher at the School of Geography, Politics and Sociology at Newcastle University, September 21, 2022

Proceedings of the National Academy of Sciences, Cuffey, et al., "Deglacial temperature history of West Antarctica," November 28, 2016

Cuffey, K.M., G.D. Clow, E.J. Steig, C. Buizert, T.J. Fudge, M. Koutnik, E.D. Waddington, R.B. Alley, and J.P. Severinghaus (2016), "Deglacial temperature history of West Antarctica," Proceedings of the National Academy of Sciences 113(50), 14249-14254. doi: 10.1073/pnas.1609132113

European Geosciences Union, "Temperature reconstruction from 10 to 120 kyr b2k from the NGRIP ice core," April 30, 2014

UC Berkeley, "About Mammoths," accessed September 20, 2022

National Oceanic and Atmospheric Administration (NOAA), "What's the hottest Earth's ever been?" June 18, 2020, "What is the average temperature on Earth?" February 25, 2022. 

NOAA, "Climate Change: Global Temperature," June 28, 2022

NOAA, "Assessing the Global Climate in 2021," Jan. 13, 2022  

Popular Science, "Yes, 50 million years ago the earth was hotter. Here’s why climate change is still a major problem," April 5, 2017

NOAA, "Climate change impacts," Aug. 13, 2021

Royal Society, "Climate is always changing. Why is climate change of concern now?" March 2020

United Nations, "IPCC report: ‘Code red’ for human driven global heating, warns UN chief," Aug. 9, 2021 

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No, research doesn’t show the Earth was 2 degrees Celsius warmer 55,000 years ago

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