Offset Half the Warming: What Models Say

Herb Simmens of the Climate Emergency Forum speaks with climate scientist Dr. Ken Caldeira at the first Climate Systems Engineering Conference at the University of Chicago. Caldeira reflects on his pioneering role in solar geoengineering and recounts the unlikely bureaucratic origins of the now‑dominant term “solar radiation management.”

This video was recorded on May 18th, 2026, and published on July 19th, 2026, and represents the opinions of the discussion participants.

Drawing on UN and peer‑reviewed modeling work, Caldeira explains why offsetting only about half of global warming could reduce temperatures without creating clear “winners and losers” or dramatically disrupting rainfall patterns. He describes how ideas that once seemed fringe have moved into the mainstream climate conversation, and what that shift means for research, governance, and public acceptance.

This short interview offers an accessible, front‑row look at current thinking on sunlight reflection methods, direct climate cooling, and the risks and opportunities of geoengineering. It’s aimed at viewers who want to understand whether solar radiation management can responsibly help cool a dangerously overheated planet.

Links:

• Frontiers in Climate Systems Engineering

• Solar radiation modification

• The Climate Triad For a Safe and Healthy Climate (CEF Video)

• One Atmosphere: An Independent Expert Review on Solar Radiation Modification Research and Deployment

• Pete Irvine

• David Keith (physicist)

• The Global Tipping Points Report 2025

• Bye Bye 1.5, What’s Next? (CEF Video)

• David W. Fahey

Special Guest:

• Dr. Ken Caldeira - is an American climate scientist known for pioneering work on ocean acidification, solar geoengineering, and the global carbon cycle. He is Senior Scientist (emeritus) in Carnegie Science’s Department of Global Ecology, a Senior Scientist at Gates Ventures, and a Visiting Scholar at Stanford University. He holds a PhD in atmospheric sciences from New York University.

Regular Panelist:

• Herb Simmens - Author, Co-founder of the Healthy Planet Action Coalition (HPAC), Climate Emergency Board Member and former college instructor.

Video Production:

• Charles Gregoire - Electrical Engineer, Webmaster and IT prime for FacingFuture.Earth & the Climate Emergency Forum; Climate Reality Leader

• Heidi Brault - Climate Reality Leader, BA(Psychology), Library & Information Technician Diploma - Video production and website assistant - Organizer and convener, Metadata technician, COP Team Lead for FacingFuture.Earth and the Climate Emergency Forum.

Attributions:

Background Music:

• Title: Through the City II
• Author: Crowander
• Source: crowander.com

Image and Video:

• Image and Video Attributions