3 ms·

I believe Robotbeats calculations are lacking if the intent is to demonstrate how much fossil fuel energy is embodied in one unit (joules, calories, etc) of foo

by bob29 5y ago

I believe Robotbeats calculations are lacking if the intent is to demonstrate how much fossil fuel energy is embodied in one unit (joules, calories, etc) of food: -hydrogen is not a primary energy, no accounting for energy needed to produce 1kg of H2 gas -producing ammonia from hydrogen consumes energy -producing corn from ammonia requires more embodied energy than sunlight - other fertilizers, *cides, fuel and construction industrial sized agricultural machinery. Only measuring the chemical energy in quantity of H2 vs the dietary calories in associated corn produced is incomplete model of fossil fuels required in agricultural production. If you are saying the urea price spike has occured in a complete isolation, like temporary specific failure of urea manufacturing , maybe its not a problem. If its one of the first noticable effects of an overall fossil fuel shortage, its going to have huge feedback effects invalidating economic models such as slowing renewable growth, making the whole economy less productive.

kragen 5y ago
I agree that it's important to include the complete model of fossil fuels in agricultural production, which is in the paper Enginerrd was citing (see https://news.ycombinator.com/item?id=29842158 https://news.ycombinator.com/item?id=29842158). It turns out that even when you do that the number is still pretty low; most of the energy is used to make ammonia. You might want to put a blank line between your list items so they don't come out as a single paragraph and/or format them with ·, •, or ●. I think the urea price spike is due to a temporary collapse in natural gas production, which is indeed one of the first overall effects of reduced excess production capacity in natural gas, or shippable natural gas anyway. I don't think an overall fossil fuel shortage would slow renewable growth, though; it increases the returns to renewable generation, and renewables production is one of the sectors of the economy least dependent on fossil fuels. I think an overall fossil fuel shortage is unlikely because coal reserves are still enormous and interconversion of different kinds of fossil fuels is lossy.

by bob29 5y ago

kragen 5y ago

I agree that it's important to include the complete model of fossil fuels in agricultural production, which is in the paper Enginerrd was citing (see https://news.ycombinator.com/item?id=29842158 https://news.ycombinator.com/item?id=29842158). It turns out that even when you do that the number is still pretty low; most of the energy is used to make ammonia. You might want to put a blank line between your list items so they don't come out as a single paragraph and/or format them with ·, •, or ●. I think the urea price spike is due to a temporary collapse in natural gas production, which is indeed one of the first overall effects of reduced excess production capacity in natural gas, or shippable natural gas anyway. I don't think an overall fossil fuel shortage would slow renewable growth, though; it increases the returns to renewable generation, and renewables production is one of the sectors of the economy least dependent on fossil fuels. I think an overall fossil fuel shortage is unlikely because coal reserves are still enormous and interconversion of different kinds of fossil fuels is lossy.