R. Lindzen, W. Happer, and W. A. van Wijngaarden

June 2024

Many people are surprised by how little warming would be averted from adoption of net zero policies. For example, if the United States achieved net zero emissions of carbon dioxide by the year 2050, only a few hundredths of a degree Celsius of warming would be averted. This could barely be detected by our best instruments.  The fundamental reason is that warming by atmospheric carbon dioxide is heavily “saturated,” with each additional ton of atmospheric carbon dioxide producing less warming than the previous ton.

Abstract:

Using feedback-free estimates of the warming by increased atmospheric carbon dioxide (CO₂) and observed rates of increase, we estimate that if the United States (U.S.) eliminated net CO₂ emissions by the year 2050, this would avert a warming of 0.0084 ◦C (0.015 ◦F), which is below our ability to accurately measure. If the entire world forced net zero CO₂ emissions by the year 2050, a warming of only 0.070 ◦C (0.13 ◦F) would be averted. If one assumes that the warming is a factor of 4 larger because of positive feedbacks, as asserted by the Intergovernmental Panel on Climate Change (IPCC), the warming averted by a net zero U.S. policy would still be very small, 0.034 ◦C (0.061 ◦F). For worldwide net zero emissions by 2050 and the 4-times larger IPCC climate sensitivity, the averted warming would be 0.28 ◦C (0.50 ◦F).

Read the entire short paper here:

Net Zero Averted Temperature Increase