@jackofalltrades @coffee2Di4 @urlyman @FantasticalEconomics @ajsadauskas @green Finally, embedded emissions for manufactured products are almost always small compared to direct emissions from their use, even for products created in the current system.

@jackofalltrades @coffee2Di4 @urlyman @FantasticalEconomics @ajsadauskas @green There are some embedded emissions from creating certain materials (e.g. aluminum, cement, steel) but in each case there are ways to produce these materials without those process emissions.

@jackofalltrades @coffee2Di4 @urlyman @FantasticalEconomics @ajsadauskas @green No, H2 is problematic for many reasons. Even if generated from electrolysis, H2 itself is an indirect GHG.

In any case, the idea that embedded emissions are a transient phenomenon follows from that fact that almost all embedded emissions come from energy use, and in a zero emissions system, that energy use would have zero emissions.

@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.

@coffee2Di4 @jackofalltrades @urlyman @FantasticalEconomics @ajsadauskas @green Technology change is complex and multifactorial, but people like to boil stuff down to simple explanations, like the Jevons Paradox. Unfortunately, these simple explanations are usually wrong.

@coffee2Di4 @jackofalltrades @urlyman @FantasticalEconomics @ajsadauskas @green People building bigger houses or buying bigger cars isn’t solely caused by efficiency improvements, and efficiency is nowhere near the most important contributor to this effect.

@coffee2Di4 @jackofalltrades @urlyman @FantasticalEconomics @ajsadauskas @green In the same way, people look at aggregate statistics for energy use and say “look, efficiency causes energy use to go up” but there are many other factors pushing energy use upwards. Overall increase in wealth is the most powerful one.

@coffee2Di4 @jackofalltrades @urlyman @FantasticalEconomics @ajsadauskas @green Efficiency wasn’t the sole reason for its ascendence, and probably wasn’t the most important reason, but the lesson most people take from this “effect” is that efficiency causes increases in energy use. That conclusion is almost always false.

@coffee2Di4 @jackofalltrades @urlyman @FantasticalEconomics @ajsadauskas @green These reasons included higher power densities, the ability to store energy, the ability to locate motive power flexibly within factories, the ability to operate underground. Steam engines were what is known as a general purpose technology, which had wide and deep applications across society.

@coffee2Di4 @jackofalltrades @urlyman @FantasticalEconomics @ajsadauskas @green The Jevons paradox is widely misunderstood and almost always overestimated. Jevons himself made the mistake of attributing to efficiency improvements the rapid adoption of the steam engine, but there were many other reasons why steam engines were widely adopted.

@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.