Posted on 21 December 2024 by Guest Author

Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. This fact brief was written by Sue Bin Park from the Gigafact team in collaboration with members from our team. You can submit claims you think need checking via the tipline.

Are we heading into an ‘ice age’?

The planet has been getting warmer since the Industrial Revolution, not colder.

Historically, ice ages have followed changes in the Earth’s relationship to the sun. Natural cycles affect the tilt of Earth’s axis and its orbit around the sun. As Earth’s axis becomes less tilted, and its orbit more elliptical, it receives less solar radiation.

These “Milankovitch” cycles occur over thousands of years. Currently, Earth’s tilt is halfway between its maximum and minimum while its orbit is nearly circular.

In the absence of human activity, Earth may have gradually cooled in the coming centuries with phases corresponding to a decreasing tilt and an increasing orbital eccentricity.

However, fossil-fuel burning and other actions have raised CO2 levels to 420 parts per million—far above the 180-280 ppm seen during past ice ages. This extra CO2 has made it harder for heat to escape the atmosphere, overpowering the natural cooling trend.

Go to full rebuttal on Skeptical Science or to the fact brief on Gigafact

This fact brief is responsive to conversations such as this one.

Sources

NASA Milankovitch (Orbital) Cycles and Their Role in Earth’s Climate

Cornell University Understanding long-term climate and CO2 change

UC San Diego The Keeling Curve Hits 420 PPM

Woods Hole Oceanographic Institution Are we heading toward another Little Ice Age?

NASA Global Temperature

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.