Fact check: Carbon dioxide has an effect on the climate, contrary to post

The claim: ‘No correlation’ between carbon dioxide emissions and the climate

A Feb. 10 Instagram post (direct link, archive link) features a screenshot of a viral tweet about climate change.

“There’s no correlation between carbon dioxide & climate & never was,” reads the text in the tweet. “CO2 is in trouble & in steady decline for millions of years. Temperatures are also falling, ‘not’ rising.”

The Twitter user, Peter Clack, is a frequent purveyor of climate change misinformation.

The Instagram post was liked more than 100 times in less than a week while the tweet received over 1,000 retweets in less than two weeks.

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Our rating: False

Greenhouse gases like carbon dioxide, methane and nitrous oxide trap heat in the atmosphere, increasing global temperatures, according to climate researchers. Atmospheric carbon dioxide levels, as well as global temperatures, are continuing to increase at a historically unprecedented rate, scientists say. .

Carbon dioxide and global temperatures are inextricably linked, say climate scientists

The claim that carbon dioxide and climate aren’t related is “completely inconsistent with legitimate science,” said Howard Diamond, a senior climate scientist at the National Oceanic and Atmospheric Administration's Air Resources Laboratory.

“That simply goes counter to all the available scientific data and research we have collected and developed over nearly 200 years,” Diamond said in an email. “We have clear empirical evidence of CO2's ability to restrict outgoing long-wave radiation – e.g., heat – from escaping from the surface of the planet back to space.”

Marcus Sarofim, an environmental scientist at the Environmental Protection Agency’s Climate Science and Impacts branch, agreed.

Scientists have determined that an unprecedented increase of carbon dioxide emissions from human activity has directly led to warming global temperatures.

The screenshotted post includes several graphs that purportedly show the lack of a relationship between carbon dioxide concentrations and global temperatures.

But Diamond said the graphs don't accurately represent the relationship between atmospheric carbon dioxide levels and global temperatures.

Fact check: No, daily temperature data doesn't disprove global warming trend

The top right chart comes from a 2001 paper by researchers at Yale University. But the graph “simply tells us that we have less CO2 today than we did, say 540 million years ago, and no legitimate climate scientist would deny that,” Diamond said.

The title “CO2 famine for the past several tens of millions of years” does not appear with the chart in the original paper.

Diamond said he had never seen the other two graphs before and wasn't sure what data was being used to create them. Neither of the other graphs includes a citation for the data.

USA TODAY reached out to Clack and Instagram user for comment. The Instagram user did not provide evidence to support the post's claim.

Atmospheric carbon dioxide and global temperatures increasing

Today's carbon dioxide levels are the highest they've been in more than three million years, according to Diamond.

In 2013, atmospheric carbon dioxide surpassed 400 parts per million for the first time since scientists started tracking levels in the mid-twentieth century. NOAA reported a high of 414 parts per million in 2021.

The post understates the recent increase in the concentration of carbon dioxide in the Earth’s atmosphere.

“The ‘modest uptake’ that is referred to is in fact an increase of global CO2 of 50% – that is not modest in any way, shape or form,” Diamond said. “In the natural world, a jump of 100 ppm, which is what we have seen over the past 60 years, would normally take about 20,000 years.”

Fact check: Plants cannot absorb all the carbon dioxide emitted into the atmosphere

The annual rate of increase in atmospheric carbon dioxide has been rapidly increasing over the past few decades, according to NOAA data. Every year, human activities such as the burning of fossil fuels release more carbon dioxide than natural processes can remove, causing the amount of carbon dioxide in the atmosphere to grow.

Earth's temperature has also risen by an average of .1 degrees per decade since 1880, or about 2 degrees in total, according to data from NASA and the NOAA.

The rate of warming since 1981 has nearly doubled, with temperatures continuing to increase at a rate of more than 0.3 degrees per decade since the 1980s.

Our fact-check sources:

• USA TODAY, Jan. 10, Fact check: No, daily temperature data doesn't disprove global warming trend

• Howard Diamond, Feb. 10, Email exchange with USA TODAY

• Marcus Sarofim, Feb. 14, Email exchange with USA TODAY

• American Journal of Science, February 2001, GEOCARB III: A REVISED MODEL OF ATMOSPHERIC CO2 OVER PHANEROZOIC TIME

• EPA, updated Aug. 1, 2022, Climate Change Indicators: Greenhouse Gases

• NASA Global Climate Change, accessed Feb. 16, Vital Signs: Carbon Dioxide

• NASA Global Climate Change, accessed Feb. 16, Vital Signs: Global Warming vs. Climate Change

• NASA Global Climate Change, accessed Feb. 16, Graphic: Carbon dioxide hits new high

• NOAA, accessed Feb. 27, Trends in Atmospheric Carbon Dioxide

• NOAA, June 17, 2022, Climate Change: Annual greenhouse gas index

• NOAA, Jan. 18, Climate Change: Global Temperature

• MIT Climate, Jan. 4, 2022, How much carbon dioxide does the Earth naturally absorb?

• Reuters, July 7, 2022, Fact Check-Plymouth Rock cannot provide an accurate measure of sea level

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This article originally appeared on USA TODAY: Fact check: Scientists say carbon dioxide levels affect the climate