Comment by southern_cross | Hacker News Reader

Comment by southern_cross | Hacker News Reader

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A carbon tax on gasoline is pretty much a non-starter, because gasoline prices have been much higher in the past than they are now but that didn't have much impact on demand, if reducing demand is your goal. (Otherwise it's just a money grab.) You would probably have to increase gasoline prices by a factor of maybe 3x or 4x or more in order to have any real impact.

Gasoline prices are headed down to below $2 a gallon in some parts of the country right now, but from what I understand California prices are going to stay at least twice that, and might even go higher. So we'll have to see what effect that has on demand there, if any.

> No comment on PM 2.5 restrictions, entirely different topic.

Carbon emissions are carbon emissions; it's not just all about CO2. PM 2.5 carbon particles and visible soot and such will likely eventually oxidize to CO2 anyway, though. And a lot of it oxidizes almost as soon as it's emitted, given its high temperature and its exposure to fresh supply of oxygen.

> Otherwise it's just a money grab.

It would make some difference in use, in the medium to long term. It would make sure nobody moves from other carbon emission sources to gasoline to save money. And most importantly, you could use 50 cents a gallon to capture a lot of carbon.

> eventually oxidize to CO2

Let me rephrase then. Those particles, treated purely as a carbon source, are pretty negligible. Any restrictions that matter would be based on non-CO2 effects.

Our real problem with the use of gasoline isn't really how much of it we use but rather how we use it so inefficiently, which of course leads to more usage and related pollution than necessary. IIRC, gasoline vehicles are only 20% or so efficient, while diesel vehicles are a bit better. And contrary to what you say, if we move more towards electric vehicles in a big way then I could foresee a day when we instead burn gasoline or some other fossil fuel equivalent in a more centralized and much more efficient manner, much like we do with natural gas today, and then use the electricity generated by that to power cars.

As to the PM 2.5 thing, like I said a lot of that gets oxidized to CO2 anyway, which adds up over time. Lately the EPA has been making a lot of noises about regulating this stuff, except that it turns out that much of it comes from places like our own kitchens. And nobody really wants the EPA involved with that part of it, hence the efforts to reign them in somewhat. But of course any talk of potentially restraining the EPA here is personified as "evil" in the press.

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