Unsubstantiated sea ice figures misused to deny 2023 was hottest year on record

A post was shared on social media claiming that 2023 was not the hottest year ever. The post also asserted that the Arctic sea ice extent was at a twenty-year high on December 26, 2023, and that the Antarctic sea ice extent surpassed levels in 1979, 1982, and 1996.

The text on the graphic read, “2023 WAS NOT THE HOTTEST YEAR EVER. Sea ice extent in both hemispheres is higher than it was in 2005. On December 26th, 2023, Arctic sea ice extent was the highest in twenty years, and Antarctic sea ice extent is higher than in 1979, 1982, and 1996. At the current rate of decline, the Arctic will be ice-free around the year 3549, when Al Gore will be 1,601 years old. Contact all politicians, media & friends. Tell them that Net Zero propaganda is totally unacceptable. CO2 is only 0.04% of the atmosphere and is vital to all life on earth. (sic)”

The post was shared in the Facebook group "Climate Con" and gained over 1,200 reactions and 816 shares. An archived version of the post can be accessed here. 

Screenshot of the viral post on social media. (Source: Facebook/Modified by Logically Facts)

However, the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) have clearly stated that 2023 was the hottest year on record. The surface temperature was above average, and the annual Antarctic sea ice extent in 2023 was the lowest on record.

What did we find?

2023 was the hottest year on record

According to a report by NASA, Earth’s average surface temperature in 2023 was the warmest on record. Global temperatures were approximately 2.1 degrees Fahrenheit (1.2 degrees Celsius) higher than NASA's baseline period (1951-1980). In comparison to the late 19th-century average, when modern record-keeping started, Earth was about 2.5 degrees Fahrenheit (1.4 degrees Celsius) warmer in 2023.

NOAA also reported that 2023 marked the warmest year on record for the planet, and, in addition to the unprecedented heat, Antarctic sea ice coverage reached a record low. 

(Source: NOAA National Centers for Environmental Information, Monthly Global Climate Report for Annual 2023)

Dr. Sarah Kapnick, NOAA chief scientist, was quoted as saying in a NOAA report from January 12, 2024, “Not only was 2023 the warmest year in NOAA’s 174-year climate record — it was the warmest by far.” The report also added that the Earth's average land and ocean surface temperature in 2023 exceeded the 20th-century average by 2.12 degrees Fahrenheit (1.18 degrees Celsius), setting a new high in NOAA's climate record from 1850-2023.

The NOAA report further highlighted that 2023 surpassed the previous warmest year, 2016, by a record-setting margin of 0.27 degrees Fahrenheit (0.15 degrees Celsius). 

Sea ice extent 

Antarctic 

In the NOAA report, it was stated that the Antarctic sea ice hit a record-low annual extent of 3.79 million square miles in 2023. The lowest maximum in September was 6.55 million sq. miles, and a record low minimum in February was 690,000 sq. miles, setting a record low for the second consecutive year. Another report by Climate.gov stated that the 2023 Antarctic sea ice winter maximum was its lowest on record by a considerable margin. In fact, 2023’s maximum was 1.03 million square kilometers less than the previous record low set in 1986. 

(Source: Howard Diamond, Data: National Snow and Ice Data Center)

Logically Facts contacted Howard Diamond, Climate Science Program Manager at NOAA's Air Resources Laboratory, for further details, who also refuted the claim. He said, “From a sea ice perspective, 2023 was highlighted by extremely large negative anomalies of sea ice in Antarctica during the southern hemisphere winter (June-August). The 2005 sea ice data is generally at or above the long-term data from 1991-2020, while the sea ice data from 2023 is well below that long-term normal.”

Arctic

Regarding the Arctic, the NOAA report stated that the Arctic sea ice averaged 4.05 million square miles in 2023, marking it as one of the 10 lowest years. The maximum extent in March was 5.64 million sq. miles, ranking fifth lowest, while the minimum extent in September was 1.63 million sq. miles, ranking sixth lowest.

According to findings from the MIT Climate Portal, Arctic sea ice has been shrinking at a rate of 12.6 percent per decade over the past 40 years. This decline is unprecedented in at least the last 1,500 years. Since 1979, U.S. government measurements reveal Arctic ice has decreased by over 2 million square kilometers.

Moreover, we could not find any report stating that the Arctic sea ice extent was the highest in twenty years on December 26, 2023. 

(Source: Howard Diamond, Data: National Snow and Ice Data Center)

Howard explained, “The Arctic sea ice fluctuates a lot over geologic time, and there have been periodic examples of a completely ice-free Arctic over the last 350,000 years. But at least some amount of year-round Arctic ice cover developed around 5,000 years ago and has been with us ever since. The spread of today’s Arctic ice is not only small compared to earlier points in human history—it’s also shrinking faster than at any point in at least the last 1,500 years.”

The verdict

Experts, backed by reliable scientific data, confirm that 2023 was the warmest year on record. Additionally, the 2023 Antarctic sea ice winter maximum was the lowest on record by a considerable margin, and the Arctic sea ice minimum extent was the sixth lowest in the same year. Therefore, we have marked this claim as false.