Recent warming is mostly due to natural climate factors…only 1/3 is attributable to the rising GHG concentrations. 

CO2’s impact on warming is likely wildly overstated. 

A recent paper by Ad Huijser, “Global Warming and the ‘impossible’ Radiation Imbalance,” published in Science of Climate Change, presents a detailed analysis that challenges the widely held assumption that rising greenhouse gas (GHG) concentrations are the sole, or even the primary, drivers of recent global warming.

Hat-tip Report 24.

By comparing observed energy trends with theoretical forcings, the study concludes that natural factors play a significant and dominant role in the warming observed since the mid-1970s.

The Discrepancy: GHG Forcing vs. Observed Warming

The study scrutinizes the Anthropogenic Global Warming (AGW) hypothesis, which attributes all observed warming solely to human-caused GHG emissions. Using satellite data from the CERES program and Ocean Heat Content (OHC) data from the ARGO float program, the author analyzed the Earth’s Top of Atmosphere (TOA) radiation imbalance—the net energy flux into the Earth’s thermal system.

Natural factors dominate

The central finding is that the assumed radiative forcing trend from GHGs is insufficient to account for the magnitude of the observed TOA radiation imbalance. The discrepancy suggests that another, significant factor must be involved in heating the planet.

The analysis points strongly toward natural forcings, specifically a long-term increase in incoming shortwave solar radiation, as the significant, dominant factor.

The paper’s findings:

Two-thirds of the observed global warming must be attributed to natural factors that increase incoming solar radiation. This is due to a natural forcing trend of about 0.035 W/m2.

Only one-third is attributable to the rising GHG concentrations. This is due to a GHG-related forcing of about 0.019 W/m2.

This increase in incoming solar energy is likely due to natural changes in factors like cloud cover and surface albedo (the reflectivity of the Earth’s surface). The study argues that the observed radiation imbalance correlates strongly with these natural processes, appearing largely unrelated to GHGs.

Implications for Future Climate Policy

The study’s findings show the planet’s warming is largely being driven by external factors (increased solar input) and not solely by an internal atmospheric resistance (GHGs), thus implying a much lower climate sensitivity than that suggested by most IPCC-endorsed Global Circulation Models (GCMs).

This new paper questions the alarmist claims about “heat in the pipeline” and suggests that future warming will be driven by natural forcings as long as they are acting, rather than historical emissions.

It underscores the importance of fully accounting for natural variability, especially in solar input, when evaluating both historical warming trends and the effectiveness of future climate mitigation policies.