Global warming happening despite 1913 Death Valley temperature record | Fact check

Kate S. Petersen, USA TODAY
·4 min read
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The claim: Post implies 1913 temperature record in Death Valley shows global warming isn't happening

An Aug. 31 Facebook post (direct link, archive link) points out that a temperature record was set when there were far less people on Earth.

"Highest temperature ever recorded 135⁰ in ~ Death Valley ~ not today but in 1913 And with six billion less human beings on Earth (sic)," reads the post.

Some users took the post as evidence that human-driven global warming is not occurring.

"But, but, it's getting hotter," wrote one commenter.

"YES, the CLIMATE CHANGE MYTH is truly complete bollox," wrote another.

The post was shared more than 500 times in two weeks.

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Our rating: Missing context

The implied claim here is wrong. Earth's average temperature has increased significantly since the late 1800s due to human greenhouse gas emissions, according to climate scientists. A single record hot temperature recorded decades ago doesn't mean the Earth isn't warming.

Death Valley heat in 1913 doesn't negate overall global warming trend

Multiple international climate agencies have detected global warming − an increase in Earth's average temperature over time. The rate of warming has doubled since 1981, according to the National Oceanic and Atmospheric Administration.

The consequences of this warming have also been observed, including sea level rise, glacial and polar ice melt and an increase in heat wave frequency. The warming is caused by an increase in greenhouse gas emissions released by humans, according to NASA.

The 1913 Death Valley world temperature record was 134 degrees, not 135 as the post claims.

And the validity of that measurement, which was recorded on July 10, 1913, is somewhat controversial, Abby Wines, a management analyst at Death Valley National Park, told USA TODAY. The record is officially recognized by the World Meteorological Organization, but some scientists say that a temperature of 134 degrees doesn't make sense in the context of the meteorological events that transpired on the day.

But even assuming that the measurement was correct, the fact that an isolated weather event could have produced a very hot temperature in the past doesn't mean that average global temperatures have not risen overall, according to Sean Birkel, the Maine state climatologist.

"Variability within the climate system can produce remarkable extremes associated with the happenstance of weather," he told USA TODAY in an email. "A single record high or low temperature in one spot on the planet does not provide the context needed for understanding climate. Climate is measured from weather conditions – including temperature, precipitation, wind, etc. – that are averaged over many years or decades.

"From near-surface temperature observations measured worldwide, scientists have found that global climate is warmer now than it was a century ago."

This rise in temperature includes Death Valley, according to Wines. For instance, nine out of the 10 hottest summers on record in Death Valley National Park have occurred since 2006, she said in an email.

Fact check: Greenhouse gases, not Milankovitch cycles, drive modern global warming

The human population has increased by about 6.4 billion people since 1900, according to Our World in Data. This is roughly consistent with the post's claim that Earth's population has increased by six billion people since 1913.

USA TODAY reached out to the Facebook user who shared the post for comment but did not receive a response.

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This article originally appeared on USA TODAY: Post on Death Valley 1913 temperature record misleads | Fact check