Fact check: Post misrepresents data, understates extent of global temperature increase

Isabella Fertel, USA TODAY
·3 min read
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The claim: The average global temperature has increased 0.134 degrees since 1978

A Feb. 7 Instagram post (direct link, archived link) features a screenshot of a tweet that includes a graph claiming to show global temperature data since 1978.

“Apparently the mean global temperature has warmed a whopping 0.134 of one degree,” reads the tweet. “This is an legit EMERGENCY (sic). #ClimateScam #ClimateEmergency.”

The graph, which was originally shared by another Twitter user, is titled “global mean temperature change: 530 months December 1978 to January 2023.”

The Instagram post has been liked more than 1,000 times in less than a week.

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Our rating: False

The 0.13 figure is a rate per decade, not an overall change. As the graph shown in the post explains, the data shows an increase of .13 degrees Celsius per decade since 1978.

Viral tweet mischaracterizes climate data represented in graph

The graph is based on data from the Earth System Science Center at the University of Alabama in Huntsville, according to text included in the graph.

John Christy, the director of the center, told USA TODAY in an email the graph appears to have been generated using data from the center’s monthly global average temperatures report.

According to Christy, the report calculates the average global temperature "anomaly" for the past month – the difference between the average global temperature of that month and the same month's average temperature between 1991 and 2020.

The dataset shows temperatures increasing by an average of 0.13 degrees Celsius per decade since 1978. The tweet screenshotted in the Instagram post incorrectly posits that the graph shows a .13-degree Celsius increase overall.

Fact check: Global temperatures have steadily risen over the past century, contrary to post

The Earth System Science Center is far from the only climate group that has reported a rise in global temperatures in recent decades.

However, the Alabama dataset reports less overall global warming than other climate organizations, including Remote Sensing Systems, an organization that uses the same data source but processes it differently.

NASA and the National Oceanic Atmospheric Administration report global temperatures have increased by about one degree Celsius (nearly 2 degrees Fahrenheit) since 1880.

Temperatures have risen at a rate of more than 0.2 degrees Celsius (0.36 degrees Fahrenheit) per decade since the 1980s, according to the National Oceanic Atmospheric Administration.

This level of global warming has already yielded significant changes to the environment, including sea-level rise, reduced sea ice and changes in weather patterns.

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This article originally appeared on USA TODAY: Fact check: Post understates the amount of global warming since 1978