Advertisement

Fact check: Earth is warming, cold events do not prove global cooling

Kate S. Petersen, USA TODAY
·5 min read

The claim: Cold events show Earth is cooling, not warming

A Dec. 15, 2022, article (direct link, archive link) circulating on social media pushes back on the notion that the Earth is warming.

"Carbon isn’t making the planet hotter. The sun is making it cooler," reads the article, published at richardsonpost.com. "The signs are everywhere for those of us not brainwashed by the global warming propaganda."

The article garnered more than 80 shares in six weeks on Facebook, according to Crowdtangle, a social media analytics tool.

Follow us on Facebook! Like our page to get updates throughout the day on our latest debunks

Our rating: False

Multiple lines of evidence show Earth's average temperature is increasing due to greenhouse gases released by human activity. Cold events, which can and do occur even on a warming planet, are not evidence that Earth's temperatures are cooling overall, researchers say. Fluctuations in solar output have a minimal impact on Earth's temperature.

Robust evidence shows Earth is warming due to human activity

The National Oceanic and Atmospheric Administration reports that global temperatures have warmed roughly 2 degrees since the 1880s and that the rate of warming has more than doubled since 1981.

Other independent climate agencies have reported similar trends.

Additionally, researchers have observed the consequences of this warming. For instance, both the Greenland and Antarctic ice sheets are losing ice, which has already contributed to sea level rise.

Fact check: Misleading claim that high Northern Hemisphere snow cover means no global warming

This warming is clearly attributable to human activity – namely the release of greenhouse gases, such as CO2, which slows the escape of heat into space, Josh Willis, a NASA climate scientist, previously told USA TODAY.

"The amount of warming we see matches what we expect based on the increased CO2 we've added," he said in an email. "The timing of the warming matches the timing of the CO2 increase caused by people. Not only that, the timing of global sea level rise matches the CO2 increase."

Cold events don't show Earth is cooling

The article claims a series of recent cold events show Earth is not actually warming. However, cold events occur even on a warming planet, Sean Birkel, an assistant professor at the University of Maine and the Maine State Climatologist, told USA TODAY.

Fact check: Misleading data used in claim alleging a global cooling trend

Climate "variability can produce weather patterns that may bring cooler than normal temperatures to some locations for some period of time," he said in an email. "Meanwhile, the global temperature is still warmer than in decades past."

Recent and short-term observations can't be used to determine climate trends, he said.

Ahira Sanchez-Lugo, a NOAA climatologist, agreed.

"Cold waves do not disprove climate change just like heat waves do not prove climate change," she said in an email to USA TODAY.

The reality of global warming has been established by observations from thousands of temperature stations spanning multiple decades, she said.

Solar output fluctuates, impact on global temperatures minimal

The article points to the existence of solar cycles to support its claim that the sun and Earth are cooling, saying that Earth is "heading into a period of solar energy decline." However, solar cycles – which each last about 11 years – typically have only small effects on Earth's temperature, Alex Young, a NASA heliophysicist, told USA TODAY.

Solar output "changes about a tenth of a percent over the solar cycle," he said in an email. "This change in solar output goes up and down and it is estimated to affect Earth’s temperature by about a tenth of a degree Celsius (0.2 degrees Fahrenheit) or less."

Fact check: Climate change caused by humans, celestial 'magnetic state' not cause of extreme heat

While it is possible for a group of cycles to exhibit less solar activity than others – an event called a grand minimum – it is not clear when such an event might occur or whether it would cause significant global cooling, according to NASA.

However, some researchers have estimated that a future grand minimum could temporarily cool the Earth by about half a degree, according to the agency.

"This would, at best, slow down but not reverse human-caused global warming," reads the agency website.

USA TODAY reached out to the website that published the article for comment.

Our fact-check sources:

Thank you for supporting our journalism. You can subscribe to our print edition, ad-free app or electronic newspaper replica here.

Our fact-check work is supported in part by a grant from Facebook.

This article originally appeared on USA TODAY: Fact check: Despite cold events, Earth is warming, not cooling