By W. A. van Wijngaarden and W. Happer

January 8, 2025

The CO₂ Coalition is pleased to present an update to a significant paper in our Climate Issues in Depth series, titled Methane and Climate.   The paper was written by CO₂ Coalition founder and board member Will Happer, a Princeton physics professor, and W. A. van Wijngaarden, of the Department of Physics and Astronomy at York University, Canada. Dr. Happer served as director of emerging technologies at the National Security Council, where he was President Trump’s top adviser on climate science.

The paper’s Abstract states:

Atmospheric methane (CH₄) contributes to the radiative forcing of Earth’s atmosphere. Radiative forcing is the difference in the net upward thermal radiation from the Earth through a transparent atmosphere and radiation through an otherwise identical atmosphere with greenhouse gases. Radiative forcing, normally specified in units of W m⁻², depends on latitude, longitude and altitude, but it is often quoted for a representative temperate latitude, and for the altitude of the tropopause, or for the top of the atmosphere. For current concentrations of greenhouse gases, the radiative forcing at the tropopause, per added CH₄ molecule, is about 30 times larger than the forcing per added carbon-dioxide (CO₂) molecule. This is due to the heavy saturation of the absorption band of the abundant greenhouse gas, CO₂. But the rate of increase of CO₂ molecules, about 2.3 ppm/year (ppm = part per million), is about 300 times larger than the rate of increase of CH₄ molecules, which has been around 0.0076 ppm/year since the year 2008. So, the contribution of methane to the annual increase in forcing is one tenth (30/300) that of carbon dioxide. The net forcing increase from CH₄ and CO₂ increases is about 0.05 W m⁻² year⁻¹. Other things being equal, this will cause a temperature increase of about 0.011 °C year⁻¹. Proposals to place harsh restrictions on methane emissions because of warming fears are not justified by facts.

Download this important paper here: Methane and Climate