logo
Brief Publisher Logo
FACT BRIEF

Is decreased cosmic ray activity driving global warming?

By Sue Bin Park
View this fact brief on Skeptical Science
Copy link
email
Copy featured image
email
NO

Over 50 years of data has produced no proof that cosmic rays are driving global warming.

While some studies attribute some small contribution to decreased cosmic ray activity, there is a scientific consensus that CO2 is the primary factor driving temperature increases worldwide.

Galactic cosmic rays are high-energy particles released by stars of the Milky Way and other galaxies. These rays hit Earth’s upper atmosphere and produce charged particles called ions.

It is suggested these ions cause an increase in cloud cover, which would shield Earth from radiation and prevent warming; thus, it has been proposed that decreased cosmic ray activity is causing rising temperatures. However, causal links between cosmic rays, clouds, and warming have been debunked by decades of data.

A 2017 paper published in the Journal of Geophysical Research found the effects of cosmic rays on clouds insignificant compared to that of natural emissions like wildfires and volcanoes.

See a full discussion of this at Skeptical Science
This fact brief is responsive to conversations such as this one.
Sources
Encyclopedia Britannica Cosmic ray
Scientific American Cosmic Rays Not Causing Climate Change
JGR Atmospheres Causes and importance of new particle formation in the present-day and preindustrial atmospheres
JGR Space Physics Can solar variability explain global warming since 1970?
Environmental Research Letters Testing the proposed causal link between cosmic rays and cloud cover
ABOUT THE CONTRIBUTOR
Skeptical Science
Skeptical Science is a non-profit science education organization. Our goal is to remove a roadblock to climate action by building public resilience against climate misinformation. We achieve this by publishing debunking of climate myths as well as providing resources for educators, communicators, scientists, and the general public. Skeptical Science was founded and is led by John Cook, a Senior Research Fellow with the Melbourne Centre for Behaviour Change at the University of Melbourne.
FACT BRIEF BY
Brief Publisher Logo
Latest fact briefs
facebook
twitter
email
email
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 fact briefs here.