Estimate: Fossil Fuels = 4% of Global Warming

Combining the results of three studies

Back in the year 2000, a little-known study had a look at the fraction of global warming explainable by slight changes in solar irradiance. The central estimate was that it explained 89% of global warming, leaving 11% to be explained by things such as the greenhouse gas effect.

The slight change in solar irradiance is pretty much ignored by the IPCC though, and the reason the authors found it to be so high is because of postulated indirect effects. Solar wind bathes the earth when solar irradiance is high, and it blocks out cosmic rays.

But cosmic rays create ions in the atmosphere which have the potential to form clouds. This means that, when the sun runs hot, it also cuts cosmic rays by so much that low cloud cover is diminished — and low cloud cover is the main way to reflect sunlight back into space, a process called albedo.

A small increase in solar irradiance is amplified approximately four-fold by the corresponding decrease in albedo — and the same in reverse (solar irradiance decreases are amplified in their direction by increasing cloud cover).

Regarding climate, the sun is 4 times more important than we thought it was.

The amplification effect was confirmed in 2021, meaning that it really is the case that the sun is the primary driver of “climate change” — though IPCC scientists are likely to dig in their heels instead of admitting this.

To add insult to injury, it was recently discovered that only 12% of currently-existing atmospheric carbon dioxide is of fossil fuel origin:

Since 1750, the share of increased carbon dioxide from fossil fuel origin is 36%, so that that purple-shaded ‘12%-of-the-total’ represents 36% of the increase.

When the indirect effects of the sun on cloud cover are joined with the minority of added greenhouse gas from fossil fuels, then fossil fuels explain 4% of recent warming.

Reference

[central estimate that solar irradiance, albeit indirectly, explains 89% of global warming] — E Pallé Bagó , C J Butler, The influence of cosmic rays on terrestrial clouds and global warming, Astronomy & Geophysics, Volume 41, Issue 4, August 2000, Pages 4.18–4.22, https://doi.org/10.1046/j.1468-4004.2000.00418.x

“The mean value 0.49° is close to the observed increase in global temperature 0.55° since 1900 (Lean and Rind 1998, Jones and Briffa 1992). Thus we find that, subject to the above assumptions, most of the global warming over the past century can be accounted for by the combined direct (solar irradiance) and indirect (cosmic-ray induced cloudiness) effects of solar activity without the need for any artificial amplification factor.”

[the indirect effect of the sun noted above is confirmed as substantial] — Svensmark, H., Svensmark, J., Enghoff, M.B. et al. Atmospheric ionization and cloud radiative forcing. Sci Rep 11, 19668 (2021). https://doi.org/10.1038/s41598-021-99033-1

[only 12% of existing atmospheric carbon dioxide came from fossil fuels] — Skrable K, Chabot G, French C. World Atmospheric CO2, Its 14C Specific Activity, Non-fossil Component, Anthropogenic Fossil Component, and Emissions (1750-2018). Health Phys. 2022 Feb 1;122(2):291-305. doi: 10.1097/HP.0000000000001485. PMID: 34995221. https://pubmed.ncbi.nlm.nih.gov/34995221/