Wood Romances

In a previous post (see that post for the cited literature), I calculated ECS from data provided in the Indicators of Global Climate Change for 2025 (IGCC25). I made 4 calculations using ΔT from two different baselines (1850-1900 and 1790-1839) and two different means for current temperature (the last 4 years and the last 12 years). I’d like to share again the calculations using a 1850-1900 baseline so I can illustrate how feedbacks amplify a warming signal. Here are the calculations in table form: Where ΔFt is total forcings since 1850 and ΔFc is the forcing for doubling CO2. Using these values and the Energy Balance Equation and averaging the two results, we come up with an ECS of 3.4°C. Notice here that to calculate ECS we didn’t have to quantify any feedbacks. We do know that there must be positive feedbacks because Planck sensitivity (Sp) is only about 1.2°C, and we’ve already seen that much warming with just over a 50% increase in CO₂. But the Planck Feedback (λp) is important ...

Ned Nikolov and Karl Zeller have published a new paper (NZ24) in the quasi-predatory MDPI journal geomatics [1] which claims to rule out the effects of greenhouse gases as a cause for the increase in GMST in recent decades. Their paper concludes, Our analysis revealed that the observed decrease of planetary albedo along with reported variations of the Total Solar Irradiance (TSI) explain 100% of the global warming trend and 83% of the GSAT interannual variability as documented by six satellite- and ground-based monitoring systems over the past 24 years. Changes in Earth’s cloud albedo emerged as the dominant driver of GSAT, while TSI only played a marginal role. They produce a graph that they believe supports their claim, which sure enough shows a decrease in the Earth's albedo over the last 24 years and a corresponding increase in absorbed solar radiation (ASR). Let me be clear here at the beginning that there absolutely has been both a decrease in albedo and a corresponding in c...

One of the more challenging aspects of climate science today is quantifying the cloud feedbacks to better constrain estimates for equilibrium climate sensitivity (ECS). It’s long been understood that low clouds generally have a cooling influence, while higher clouds increase warming via the greenhouse effect. Previous attempts at quantifying the net feedback have produced results where the confidence interval is larger than the estimate. For instance, Andrew Dessler’s estimates[1][2] were +0.50 ± 0.75 W/m^2/K over a 10 year period. Zhou’s estimate[3] was −0.16 ±0.83 W/m^2/K. Attempts at simulating clouds in some of the CMIP6 models have produced ECS values that are likely too high,[4] though many of these issues have since been largely resolved.[5][6][7]. A new study,[8] however, has succeeded at quantifying these cloud feedbacks at 0.43 ± 0.35 W/m^2/K. This means that for every 1 C warming, we can expect an additional 0.43 W/m^2, amplifying warming. Given these results, there is just...