Fact brief – Has the greenhouse effect been falsified?
Posted on 16 September 2025 by Sue Bin Park
Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. You can submit claims you think need checking via the tipline.
Has the greenhouse effect been falsified?
The greenhouse effect is basic physics that has been known for nearly 200 years. Without it, the Earth would not be warm enough for life.
Greenhouse gases like carbon dioxide act like an insulating blanket. By preventing some outgoing heat from escaping the atmosphere by absorbing and re-emitting it, they keep Earth around 33°C (59°F) warmer than it would be otherwise.
In comparison, the Moon, lacking an atmosphere, swings from 120°C (248°F) in daytime to -130°C (-202°F) at night. Venus’s thick CO2-rich atmosphere always keeps surface temperatures above 450°C (842°F).
Laboratory tests show these gases trap heat at specific wavelengths, and satellites have directly measured those same wavelengths being trapped and reradiated.
It is no coincidence that as human-caused CO2 continues to increase in the atmosphere, more energy is being absorbed from the Sun than is being lost back into space, all while surface and air temperatures continue to rise.
Go to full rebuttal on Skeptical Science or to the fact brief on Gigafact
This fact brief is responsive to quotes such as this one.
Sources
NASA What is the greenhouse effect?
NASA Weather on the Moon.
NASA Venus facts.
NASA Climate Forcings and Global Warming.
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About fact briefs published on Gigafact
Fact briefs are short, credibly sourced summaries that offer “yes/no” answers in response to claims found online. They rely on publicly available, often primary source data and documents. Fact briefs are created by contributors to Gigafact — a nonprofit project looking to expand participation in fact-checking and protect the democratic process. See all of our published fact briefs here.
