No, Earth was not warmer 55,000 years ago than it is today

What is the claim?

A clip from the podcast The Joe Rogan Experience is circulating on Facebook in which American businessman Dan Peña calls global warming "a joke" while promoting the claim that "Earth was warmer 55,000 years ago than it is today by 2°C." The post (archived here) has gained over 26,000 likes.

A clip showing Dan Peña claiming that climate change is a joke. (Source: Screenshot/Facebook/Modified by Logically Facts)

The full version of the podcast is available on YouTube (archived here), published on March 11, 2017. At the timestamp 1:04:57, Peña says that on a trip to the magnetic south pole of the Earth, a group of scientists told him that the Earth was warmer 55,000 years ago than it is today by 2°C. He continues, "I asked what about global warming? Simultaneously all ten scientists start laughing. All 10 PhDs from MIT, Stanford, Caltech started laughing because global warming is a joke." He further adds that climate change is cyclic and "if we wait 10,000 years there won't be any global warming."

However, this claim is false, and scientific consensus shows that the earth was not warmer 55,000 years ago.

What is the truth?

The average global temperature now is approximately 59°F (15°C).

 Dr. Howard Diamond, Climate Science Program Manager at NOAA's Air Resources Laboratory, told Logically Facts, "The most recent ice age occurred between 120,000 and 11,500 years ago, and so 50,000 years ago, it is clear that temperatures were definitely lower than they are today." He added that we are currently in a period of milder climate between ice ages called an interglacial period.

An article published in The Conversation titled "Is it really hotter now than any time in 100,000 years?" and authored by Darrell Kaufman, Professor of Earth and Environmental Sciences at Northern Arizona University, also notes that the Earth was considerably cooler 55,000 years ago than it is today.

A chart in the piece shows reconstructions of temperature over time, with measured records since 1850 and the rest calculated by paleoclimatologists. It indicates that the temperature 55,000 years ago was around 4°C lower than the pre-Industrial Revolution average temperature.

The average global temperature in the 20th century was around 57.0°F (13.9°C). According to 2023 data, the average global temperature reached around 2.12 °F (1.18 °C) above the 20th-century average, amounting to approximately 59.12°F (15.08°C). This was 2.43 °F (1.35 °C) above the pre-industrial average (1850-1900), according to the same dataset.

Graph showing the average temperature for the past 150,000 years relative to the pre-Industrial era. (Source: Screenshot/The Conversation)

Similarly, a graph by the National Oceanic and Atmospheric Administration (NOAA), a U.S. scientific and regulatory agency, shows that temperatures around 55,000 years ago were much below the pre-Industrial Revolution average temperature.

Graph showing average temperatures for the past 800,000 years relative to pre-industrial temperature. (Source: Screenshot/NOAA) 

Climate cycles

Dr. Diamond explained that a cycle of global warming and cooling over millions of years is natural, but there is nothing natural about the rise in CO2 that the Earth has seen over the past 370 years. 

Dr. Diamond further explained, "If there were no human influences on climate, Earth's current orbital positions within the Milankovitch cycles, coupled with relatively low solar activity, predict our planet should be actually be cooling, not warming as it is now, continuing a long-term cooling trend that began 6,000 years ago." An article by NASA also confirms this.

Milankovitch cycles take into account the Earth's orbit's eccentricity, obliquity, and precision, and are used to understand long-term changes in the planet's climate, as these three variables affect the amount of sunlight received by the Earth. Some climate change deniers use higher temperatures caused by these cycles hundreds of thousands and millions of years ago to deny anthropogenic climate change. Logically Facts has debunked such a claim earlier. 

According to NOAA, the current rate of increase in carbon dioxide is also 100 times greater than the previous natural increase during the end of the last ice age, 11,000-17,000 years ago. This shows that the increase in carbon dioxide levels we are currently experiencing is not a natural phenomenon but is greatly affected by human activity.

A letter published in the scientific journal Environmental Research in 2021 that randomly analyzed 3,000 peer-reviewed scientific papers out of a data set of 88,125 papers showed that there was a 99 percent consensus on human-caused climate change.

The verdict

This claim is false, as the Earth's temperature was much cooler 55,000 years ago than it is now. Even though the Earth has naturally seen higher temperatures hundreds of thousands and millions of years ago, scientists analyzing Milankovitch cycles say that the Earth should be cooling and not getting hotter right now. This shows that climate change is very real, and human activity is causing the Earth to warm up.