The claim: man-made climate change is a hoax
President Joe Biden pledged at a virtual climate summit, held on Earth Day, to halve greenhouse gas pollution in the United States by 2030 to help mitigate the global climate crisis.
“The science is undeniable,” Biden said at the April 22 summit. “The cost of inaction keeps growing.”
But some still deny.
Climate skeptics don’t believe climate change is human-induced, despite overwhelming scientific evidence to support the conclusion. Some do not recognize global warming at all.
A Facebook user posted on April 19, claiming, among other things, that man-made climate change was a “scam.”
“Don’t dare question it or else you’ll be branded a ‘climate change denier’ and get canceled for it,” the user wrote.
The Facebook account that posted the complaint did not respond to a request for comment.
Earth Day:Biden promises 50% cut in US greenhouse gas emissions
What is global warming?
While natural forces can contribute to global temperature changes, scientific evidence shows that warming has accelerated since the mid-20th century.
The “hockey stick” graph introduced in 1998 in the journal Nature shows relatively flat temperature fluctuations over hundreds of years before a steep slope, especially over the past 50 years.
The graph has been controversial among climate skeptics, but was approved in 2006 by the National Academy of Sciences.
Most scientists claim that the steep slope is related to human-made emissions in the post-industrial period. This is the result of the “greenhouse effect,” where the planet heats up as gases that prevent heat from escaping build up in the atmosphere.
The concentration of carbon dioxide in the atmosphere from human activities has increased by 47% since the start of the industrial revolution, according to NASA. Accumulations of water vapor, methane, nitrous oxide and chlorofluorocarbons also contribute to the greenhouse effect.
With global warming, weather conditions have changed, melting glaciers and ice caps have caused sea levels to rise, and heat waves have become longer and more intense.
“On Earth, human activities are altering the natural greenhouse,” explains a NASA website on the causes of climate change.
While climate deniers suggest that the causes of climate change are uncertain, scientists have concluded with a high degree of certainty that the dominant cause of warming is the greenhouse gases produced by humans that get trapped in it. atmosphere.
A synthesis of the Special Report on Climate Science: Fourth National Climate Assessment says it is “extremely likely” – that is, at least 95% – that unprecedented concentrations of carbon dioxide, methane and nitrous oxide in the atmosphere driven by economic and population growth since the pre-industrial era are the dominant cause of warming.
In short, humans are the root cause of climate change.
The Intergovernmental Panel on Climate Change, established by the United Nations in 1988, wrote the report. But other research organizations and government scientists have come to the same conclusion.
The National Oceanic and Atmospheric Administration, NASA, the National Science Foundation, the National Research Council and the Environmental Protection Agency all agree that “the Earth is warming mainly due to the increase in gas scavenging. heat produced by humans, ”according to an article on NOAA. Climate.gov website.
NOAA also mentions a 2004 study in the journal Science, supported in a 2016 review article, which reviewed 928 peer-reviewed articles in scientific journals. None of the documents disagreed with the consensus.
The backstory:How and Why the USA TODAY Network Checks for Issues, People, and Statements in the News
A 2018 Congressional Research Service report summarizing “evolutionary assessments” of the causes of climate change since the early 19th century stated: “The current scientific assessment of climate indicates a high (extremely likely) confidence that human influence is the dominant cause of the observed warming. for half a century.
The report says the finding is relatively recent, in part because of better science. This includes better measurement technologies, the development of better simulation models and longer series of observations.
“We have independent evidence that says when you add greenhouse gases, you get the changes that we see,” Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, said in a State of the Planet from Columbia Climate School 2017. “If you don’t introduce greenhouse gases, you don’t. And if you add all the other things people think about – changes in Earth’s orbit, changes in ocean circulation, El Niño, changes in land use, air pollution, smog, l ozone depletion – all of these things, none of them actually producing the changes that we see in multiple datasets in multiple areas of the system, all of which have been replicated independently. “
Our decision: False
The claim that man-made climate change is a hoax is FALSE, based on our research. The scientific consensus is that climate change is the product of man-made gases that trap heat on Earth. Governmental organizations and articles published in scientific journals have concluded with a high degree of certainty that climate change is human-induced.
Our sources of fact-checking:
- Encylopedia.com, accessed April 22, Hockey Stick Curve
- The New York Times, June 22, 2006, “Science Panel Backs Study on Warming Climate”
- National Oceanic and Atmospheric Administration, August 14, 2020, Climate change: annual greenhouse gas index
- NASA, consulted on April 22, “Causes of climate change”
- NASA, accessed April 22, “Effects of Climate Change”
- NASA, accessed April 22, “Scientific consensus on climate change”
- Special Report on Climate Science, accessed April 22, Fourth National Climate Assessment (NCA4), Volume I
- Intergovernmental Panel on Climate Change, accessed April 22, Summary of the 2014 Climate Change Synthesis Report for Policymakers
- Bloomberg, June 24, 2015, “What Really Heats the World?”
- National Oceanic and Atmospheric Administration, February 3, 2020, “Isn’t there a lot of disagreement among climatologists over global warming?”
- Congressional Research Service, February 1, 2018, “Evolving Assessments of Human and Natural Contributions to Climate Change”
- Columbia Climate School State of the Planet Blog, April 4, 2017, “How We Know Today’s Climate Change Is Not Natural”
Thank you for supporting our journalism. You can subscribe to our print edition, ad-free app, or e-journal replica here.
Our fact-checking work is funded in part by a grant from Facebook.