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Totally agree. We're a lot closer to sustainable aviation fuel (SAF) than we are to electric airliners. Another thing to consider is that aviation only accoun

Totally agree. We're a lot closer to sustainable aviation fuel (SAF) than we are to electric airliners. Another thing to consider is that aviation only accounts for around 2% of global carbon emissions. If SAF ends up being harder to make than expected, it might end up making sense to keep extracting + refining some fossil fuels and mitigate them using some other means (mineralization, perhaps). Cheap carbon dioxide removal could end up leading to some rather unintuitive outcomes.

MrVandemar 3y ago
> aviation only accounts for around 2% of global carbon emissions You mean: “aviation accounts for around 2% of global carbon emissions”. There is no only about it. 2% is actually a meaningful and substantial number when you consider the pie-chart it's sliced out of represents a collossal problem.
rhelz 3y ago
After a plane burns all its jet fuel to fly where it is going, we will have to expend even more than that much energy to suck the C02 out of the air again. Flying will cost at least 2x as much as it does today.
- Slava_Propanei 3y ago
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- zamfi 3y ago
  Jet fuel is less than 25% of the cost of running an airline. Flying will cost more, but not necessarily 2x more. Plus that's only if we can't synthesize jet fuel from all that CO2 we're extracting from the air.
- topkai22 3y ago
  That assumes that price is entirely determined by energy cost, that you need to convert CO2 to a chemical with the same potential energy level as jet fuel, and that energy costs are the same and constant across sources. That’s not true. Fuel accounts 30-50% of the costs of air travel. A straight doubling of fuel costs would not double air travel costs (although it would hurt) The CO2 emitted from air travel wouldn’t necessarily need to be converted back to a very high energy molecule like jet fuel. I’m not a chemist, but I’m pretty sure there are polymers that you can bind the carbon into and not be nearly as energy intensive as recreating petroleum molecules. Finally, wind and solar electricity generation are already generally cheaper than any fossil fuel generation besides nat gas. The EIA (via Wikipedia) had that at around 2x cheaper solar versus diesel generation, and solar and wind continue to see cost improvement. All that being said, any carbon elimination scheme is going to have a cost, but the theoretical cost efficiency can be much better than if you assume energy is 1-1 with cost.

MrVandemar 3y ago

> aviation only accounts for around 2% of global carbon emissions You mean: “aviation accounts for around 2% of global carbon emissions”. There is no only about it. 2% is actually a meaningful and substantial number when you consider the pie-chart it's sliced out of represents a collossal problem.

rhelz 3y ago

After a plane burns all its jet fuel to fly where it is going, we will have to expend even more than that much energy to suck the C02 out of the air again. Flying will cost at least 2x as much as it does today.

Slava_Propanei 3y ago
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zamfi 3y ago
Jet fuel is less than 25% of the cost of running an airline. Flying will cost more, but not necessarily 2x more. Plus that's only if we can't synthesize jet fuel from all that CO2 we're extracting from the air.
topkai22 3y ago
That assumes that price is entirely determined by energy cost, that you need to convert CO2 to a chemical with the same potential energy level as jet fuel, and that energy costs are the same and constant across sources. That’s not true. Fuel accounts 30-50% of the costs of air travel. A straight doubling of fuel costs would not double air travel costs (although it would hurt) The CO2 emitted from air travel wouldn’t necessarily need to be converted back to a very high energy molecule like jet fuel. I’m not a chemist, but I’m pretty sure there are polymers that you can bind the carbon into and not be nearly as energy intensive as recreating petroleum molecules. Finally, wind and solar electricity generation are already generally cheaper than any fossil fuel generation besides nat gas. The EIA (via Wikipedia) had that at around 2x cheaper solar versus diesel generation, and solar and wind continue to see cost improvement. All that being said, any carbon elimination scheme is going to have a cost, but the theoretical cost efficiency can be much better than if you assume energy is 1-1 with cost.