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Comment by thinkingkong | Hacker News Reader

Here's a fun thought experiment.

Let's just say we shifted our demand for lots of the climate change contributors. From what I can gather the top contributors would be liquid fuels, solid fuels, and gaseous fuels. Right off the bat we know we can cut coal and shift to other technologies. But in the case where we want to shift our liquid fuel consumption, things get tricky. For example, we might be able to move our entire car fleet to electric, but we're still way far off from doing that for planes. So at some point in the future, we'll still need jet fuel, but we'll have reduced our demand for gasoline tremendously. They come from the same source and happen as part of the same process.

So what happens when gasoline costs negative dollars?

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Your instincts are roughly correct, but in case you wanted a couple dozen graphs to flesh it out you'll like this link: https://ourworldindata.org/co2-and-other-greenhouse-gas-emis...

Honestly its much less compliated than internet debate artists make it out to be. #1 coal, #2 oil, #3 gas. Cement and agriculture/land-use are marginal things we can worry about in 2040. For right now, its one two three. Coal, oil, gas. Anyone derailing into other things is failing to quantify and prioritize.

Also as you point out coal is basically already solved, its purely a combination of regulation and cost-curves of the alternatives. Oil can be 80% solved using electrification today, and hopefully over the course of the next 20 years that turns into a 95% solved thing via improved batteries or fuel cells or both.

The last 5% of oil is, as you point out, jet fuel. It is by far one of the hardest pieces of the puzzle to solve. I think the short version is that the price of air travel is going to have to double to both dramatically reduce demand for it and to fund carbon-offset measures for what remains. Of course you can never tell upper middle class people this, they lose their shit at the thought of not being entitled to vacation and be tourists anywhere they want as much as they want.

The third part, gas, is going to be harder than coal and oil because its so damn cheap right now. We can speculate a lot about what could replace 50% of it, but the other half is a lot tricker.

However, again, this is a prioritization and timeline constraint problem. Solve coal NOW. Solve oil over the course of the next decade. Gas we'll circle back and see what we can do in like 2035. We'll have our hands plenty full solving for coal and oil now.

Its already completely technologically and economically feasible to get rid of 95% of coal, 80% of oil, and 50% of gas over the next 10 years in america and 20 in the overall world. That will reduce us from ~40Gt/year down to around 5Gt/year. Then we figure out how to phase in negative-emissions tech.

> I think the short version is that the price of air travel is going to have to double to both dramatically reduce demand for it and to fund carbon-offset measures for what remains. Of course you can never tell upper middle class people this, they lose their shit at the thought of not being entitled to vacation and be tourists anywhere they want as much as they want.

In Europe at least, I think the working and aspiring middle classes would be harder hit. The low end of air travel has become ridiculously cheap really, with pan-continental flights with Ryanair or whatever costing less than a train across England.

Slap a flat-fee carbon tariff or even just higher duty on it and it'll be a different market.

It will still cost money to produce and transport even if demand is low so the price will not be negative. Who is going to pay you to take gasoline when they could just burn it themselves very cheaply to get rid of it? Presumably supply will also decrease, refineries will shut down. It may even become more expensive as economies of scale are lost.

In the short term as demand decreases I imagine governments will ramp up taxes to keep the price steady or climbing in order to avoid encouraging people to increase consumption.

Transportation is not the only thing that threatens the environment. In fact, the clothing industry and farming are harming the environment more than driving our cars is as far as I know.

Sorry not so. Here's a graph that breaks emissions down by economic sector: https://ourworldindata.org/co2-and-other-greenhouse-gas-emis...

Here's the breakdown within the US by economic sector, and then the Transportation sector broken down by vehicle type: https://www.epa.gov/greenvehicles/fast-facts-transportation-...

Clothing and red-meat are particularly acute impact activities of wealthy western lifestyles, but its very hard to top cars. The very thing they do is oxidize hydrocarbons.

Thanks, good to know when I am wrong.

> but its very hard to top cars

I haven't found cars specifically in your links and I doubt that private cars are one of the biggest pollutants.

Also, stressing that I am not countering your point, CO2 is not the only factor of course. The clothing industry, as well as the chemical industry, is responsible for pumping lots of toxins into the water, which is also bad.

> I haven't found cars specifically in your links and I doubt that private cars are one of the biggest pollutants.

If you click the second link there will be two large pie charts on your screen.

The first shows total US greenhouse gas emissions by sector, in which Transportation is 29% and Agriculture is 9%

The second shows a breakdown of Transportation by vehicle type. The largest part of which, at 59%, is "light duty vehicles", which is the term for everything from a moped to a pickup truck.

59% of 29% is about 17%, vs agriculture's 9%. Making cars roughly twice as "bad" as farming from a greenhouse gas perspective.

Plastic keeps it from going negative?

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