Wood Romances

A paper was published recently in an MDPI journal Atmosphere [1] by Joachim Dengler and John Reid (DR) that aims to show that we can keep global temperatures from eclipsing the 1.5 C target "if we keep living our lives with the current CO2 emissions – and a 3%/decade efficiency improvement."[2] I saw this paper highlighted on Judith Curry's blog , so I figured it deserved some attention. The basic argument is that the amount of absorbed CO2 increases with CO2 concentration, such that at 475 ppm CO2 we will achieve net zero emissions - natural sinks will absorb 100% of our emissions and CO2 concentrations will stabilize if we improve our efficiency at 3% per decade. And if this occurs, GMST will stabilize at 1.4 C above preindustrial levels, keeping us below the 1.5 C thresholds from the Paris Agreement and IPCC targets. This is a really odd paper. DR begin by acknowledging that a big portion of understanding how our carbon emissions affects climate depends on what percent...

Little Big Econ State Forest (just because it's pretty) Any given climate forcing affects the Earth's Energy Imbalance (EEI) - that is, it affects the amount of energy entering the climate system vs energy escaping into space. When a forcing occurs, such as from an increase in CO2, the imbalance is created and surface temperature increases until EEI returns to equilibrium (that is, EEI = 0). But how long does this take? That is, what is the lag between a climate forcing and the new equilibrium temperature? It turns out, this depends on sensitivity and the rate of temperature increase, but it is possible estimate the time to achieve this equilibrium with a forcing. But this is going to be rather math-intensive. Apologies in advance! We can begin with a simple energy balance equation: (1) ΔF = ΔT/ λ  + EEI, where λ is sensitivity (ECS/F2x) ECS is Equilibrium Climate Sensitivity F2x is the forcing for doubling CO2 EEI is the Earth's Energy Imbalance ΔF is the change in radiati...