@jackofalltrades @coffee2Di4 @urlyman @FantasticalEconomics @ajsadauskas @green People with houses and EVs powered by solar PVs + batteries is the simplest example. The embedded emissions are a transient phenomenon, once we’ve decarbonized supply chains that issue will be solved.

@coffee2Di4 @jackofalltrades @urlyman @FantasticalEconomics @ajsadauskas @green PS. Anyone talking about this issue needs to distinguish between absolute decoupling of ENERGY USE from economic activity and absolute decoupling of EMISSIONS from economic activity. Achieving the latter is much easier than the former, given the many ways to power modern tech with zero emissions, but people often conflate the two.

@urlyman @FantasticalEconomics @jackofalltrades @ajsadauskas @green We need to pursue absolute decoupling of emissions from GDP, and we can, while also doing all the other things forced on us by more than 3 decades of dithering (like carbon removal). That’s the only way out of this mess.

@urlyman @FantasticalEconomics @jackofalltrades @ajsadauskas @green No, that is not the case. Efficiency doesn’t cause increases in energy use except on the margin for a limited number of cases. What drives emissions up is people getting wealthier in a mostly fossil energy system. When we transform the system to be much less fossil intensive then emissions can come down even if GDP goes up.

@jackofalltrades @urlyman @ajsadauskas @green Of course it’s important to track emissions and materials associated with imported goods manufactured elsewhere, but that doesn’t change the plain fact that there is vast potential for improving efficiency, and that potential keeps increasing all the time as technology improves.

@jackofalltrades @urlyman @ajsadauskas @green As I was careful to say in my posts above, evidence for relative decoupling is very strong. Absolute decoupling is something still being debated, but there’s no reason in principle why it can’t be done, and people who just point to historical data to argue it can’t be done have to address the literature on energy and material efficiency potentials, which are vast and largely untapped.

@urlyman @ajsadauskas @green We talk about this more here: Koomey, Jonathan, Zachary Schmidt, Karl Hausker, and Dan Lashof. 2023. "Abandon the idea of an “optimal economic path” for climate policy." Invited Commentary for WIREs Climate Change. vol. e850, July 2. [http://doi.org/10.1002/wcc.850 ]

@urlyman @ajsadauskas @green Further, we’ve never faced a climate crisis before, and we may not get our act together, but we should and I hope we will. If we do, those actions will be unprecedented and rapid, and that will make many things possible that weren’t possible before.

@urlyman @ajsadauskas @green My own view is that just because it’s never happened before doesn’t mean it couldn’t happen. Also, as we shift from combustion based electricity generation (which has 50-60% combustion losses) to renewables we will simply eliminate half of the primary energy associated with fossil electricity generation, which will substantially accelerate the reduction in PE/GDP. The Roser tweet also gives more data, so it’s worth looking more.

@urlyman @ajsadauskas @green There are people who are skeptical about ABSOLUTE decoupling, which means they think relative decoupling will not be enough to meet climate goals or even to reduce absolute energy consumption. I personally think there’s no reason why absolute decoupling isn’t possible, but those arguing for this point of view point to history and find very few examples of it.

@urlyman @ajsadauskas @green What the graph shows is that there was rough constancy in energy/GDP for the US from 1949 through about 1970, then the ratio of PE to GDP dropped substantially almost continuously for the next almost five decades.

@urlyman @ajsadauskas @green It’s important to distinguish “relative decoupling” from “absolute decoupling”. To state that there’s a 1 to 1 relationship between GDP and primary energy use is a statement about relative decoupling, and the evidence disproving such a statement is very strong. Here’s a graph from our 2015 article updated to 2019 (working on an update through 2022 now).