Yoshihiro Muronaka 
International Environment and Economy Institute (IEEI)
July 22, 2025

Introduction 

The report titled ‘Physics Demonstrates That Increasing Greenhouse Gases Cannot Cause Dangerous Warming, Extreme Weather or Any Harm’ (June 7, 2025), authored by Professor Emeritus Richard Lindzen of MIT and Professor Emeritus William Happer of Princeton University, questions the scientific basis and economic consequences of modern ‘Net Zero’ climate policies. 

1. Summary and Purpose 

At the beginning of the report, the authors emphasize that CO₂ is essential for photosynthesis, and doubling its concentration (from 420 ppm to 840 ppm) could increase crop and forest yields by about 40%, while the temperature rise would remain minimal—no more than 0.28 to 0.56°C. 

They criticize the claims by the IPCC and EPA that ‘CO₂ is the main driver of climate warming’ as being based merely on governmental consensus and climate models, lacking the core scientific principle of hypothesis testing. They argue that policies like the EPA’s endangerment finding rely excessively on ‘selective generalization of evidence’ and ignore actual physical observations. Against this backdrop, they question the scientific and social validity of Net Zero policies and call for their redesign based on empirical measurements. 

Read the full report here:

Muronaka Yoshihiro Lindzen Happer Report IEEI 7-22-25