Data from random days doesn't teach us about sea ice or global warming | Fact check

The claim: Climate change is a 'scam' because Antarctic sea ice covered more area on March 9 than 27 years earlier

A March 10 X post (direct link, archive link) shows two National Snow & Ice Data Center maps depicting Antarctic sea ice extent − the area of the sea covered by ice. One is dated March 9, 1997, and the other is labeled with the same date in 2024.

"Antarctic sea ice extent is higher today − 3,165,625 km. sq. − than it was 27 years ago − 3,075,000 km. sq. − #ClimateScam," reads the caption.

The post was reposted more than 700 times on X and also circulated on Facebook.

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Our rating: False

It is no secret Antarctic sea ice has not exhibited a statistically significant overall decline due to climate change − it's been publicly reported by major climate research agencies. But comparing sea ice area on two random days doesn't prove a long-term trend or lack thereof. Multiple lines of evidence show Earth's climate is changing and having an array of impacts on temperature and polar ice.

Antarctic sea ice currently shows no long-term trend

Sea ice cover fluctuates annually and seasonally due to natural variability in the weather, Walt Meier, a senior research scientist at the National Snow and Ice Data Center, previously told USA TODAY. Even if sea ice is in overall decline, such as in the Arctic, each year doesn't necessarily have less cover than all previous years.

"This is probably even more the case in the Antarctic because there is so much variation," Meier said. "The way to understand the changes in the ice cover is to look at the long-term trends. Comparing two random days − or months or years − does not provide any insight into sea ice conditions."

Multiple climate agencies have publically reported that, while Earth is clearly warming, the overall trend in Antarctic sea ice cover since 1979 has been nearly flat.

"For the most part, the Antarctic sea ice trend is flat," Meier said. "2023 was so low that the trend did go from very slightly positive to very slightly negative in most months. But effectively the trend has been zero."

But that doesn't mean global warming isn't happening.

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"Global warming is, well, global," Meier said. "In response to greenhouse gas emissions, the Earth as a whole is warming as expected − if not faster than expected. Within the global average, there is also expected to be a lot of variability. It doesn’t make sense that all regions are going to respond at the same pace."

It's too early to know for sure, but low sea ice cover in the last few years, including record lows in 2023, has led some scientists to suspect that Antarctic sea ice may be starting to respond to climate change, Ella Gilbert, a climate modeler at the British Antarctic Survey, wrote in Carbon Brief.

"Deciphering the role of climate change in Antarctic sea ice trends is much more complicated than in the Arctic because conditions are impacted by so many competing factors," she wrote. "However, the sheer magnitude of 2023’s sea ice lows suggests that something unusual is happening."

Meier told USA TODAY the five-day running average sea ice cover for March 9 in 1997 was 2.756 million square kilometers, compared to 2.808 million on that day in 2024. He said he wasn't sure where the numbers in the post came from, though they could have been calculated from a different data set.

Earth's climate is clearly changing

While it is unclear whether Antarctic sea ice has begun a long-term decline, it is clear that global warming is happening. Multiple independent, international climate research organizations have documented a long-term increase in average global atmospheric temperatures.

Ocean warming has also been documented along with the consequences of both marine and atmospheric warming, including:

The X user who posted the claim could not be reached.

Reuters also debunked the claim.

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This article originally appeared on USA TODAY: No, Antarctic sea ice isn't evidence of climate 'scam' | Fact check