Nathan Myhrvold — former Microsoft exec, kajillionaire, inventor, founder of Intellectual Ventures, and all-around polymath genius type — was quoted in the book SuperFreakonomics saying dismissive things about climate activists. He took some heat for it at the time and the experience apparently convinced him that he needs to get a better handle on things climate and energy-related. Myhrvold built a specialized set of models to capture the global temperature effects of transitions to low-carbon energy of varying speeds, using varying technologies. Flash forward a few years: Myhrvold is out with a paper on his results, co-authored with respected climate scientist Ken Caldeira, published in Environmental Research Letters. The results are … grim.
In their results, Myhrvold and Caldeira highlight a few poorly appreciated but crucial features of energy transitions. The first is that they take quite a while to have an appreciable effect on CO2 concentrations. The world’s oceans have considerable “thermal inertia” — it takes them a long time to absorb heat and a long time to release it. Even after CO2 concentrations start falling, it will take the oceans a while to stop releasing the excess heat they’ve already absorbed.
So much CO2 accumulation is already “baked in” that temperature will continue to rise for a while even in the context of rapid emission reductions. We’ve already gotten drunk on fossil fuels; there’s no way to avoid the hangover.
The consequences of this time lag are twofold. First, substantially affecting global temperature in the first half of the century is all but impossible; even to secure temperature reductions in the second half of the century, a rapid transition to clean energy needs to begin immediately. Second, lower-carbon energy — like, say, natural gas — just won’t do it. If we transitioned to something with half of coal’s emissions, it would take more than a century to produce even a 25 percent decline in CO2 relative to the status quo baseline. By then we’d be cooked.
Myhrvold and Caldeira have shown in pretty stark terms that, if we’re not willing to substantially reduce population growth or economic growth, we’re going to need an absolutely gargantuan amount of zero-carbon energy, without delay. They conclude: We’re going to need “immediate and precipitous anti-carbon initiatives.”
Here’s Caldeira discussing the paper: