I’m a bit doubtful about the potential for ever-more improved energy efficiency in existing technology. I’m remembering back 10 years to something I studied at university and then never again used, but if I am remembering right there are some pretty hard limits on how efficient engines can be. And it’s lower than 100% efficiency (does Cournet engines ring a bell to anyone?).

Well obviously, 100% is the theoretical limit, because an engine can’t do more work than the energy you put into it. But ICE engines are currently something like 25-30% efficient, which is horrible. So there’s a lot of room for improvement, assuming there is adequate economic incentive to do so. And gas-electric hybrids increase efficiency further by taking energy that would otherwise be wasted as heat (for example, when breaking) and storing it in a battery. I do not think it is unreasonable that we will see 100mpg prototypes within a few years. They are also experimenting with “plug-in” hybrids that give the batteries an initial charge, which keeps the gas engine from needing to be used for short trips, when it is least efficient. Some tinkerers have modified their own hybrids to produce cars that exceed 100mpg, but of course the extra energy ultimately comes from a power plant, which may be worse for the environment than burning gas. But this is where the technology is heading.

PEM fuel cells are far more efficient than ICEs, something like 60% or more, but there are so many problems with hydrogen that it’s not really worth considering. The penultimate emissions-free vehicle will be an electric car with litium-ion batteries, which will have the same range as today’s cars and will be about 90% or more efficient. The transitional species will be gas-electric hybrids, and after that, plug-in hybrids. The real challenge will be to produce large amounts of electricity without pollution or greenhouse gas emissions. This is no small order, but since the transition will be relatively slow, we’ll have time address that problem.

Furthermore, the closer you get to the theoretical limit, the harder it comes to get any closer. The approach is asymptotic. Consequently, I don’t think that just beause automative engineers made, say, 20% efficiency gains in the last 20 years, that we can depend on them making 20% efficiency gains indefinitely.

Yup. It’s John Quiggin. I think that this one isn’t quite as good as claiming that freeing Eastern Europe from Soviet domination wasn’t worth the expected 100 million deaths from world thermonuclear war, but it’s up there.

the single most sensible thing said in political philosophy in the twentieth century was JK Galbraith’s aphorism that the quest of conservative thought throughout the ages has been “the search for a higher moral justification for selfishness”.

Conservatives’ technophilia is a means, not an end.

Even one of the more expensive ways of mitigating CO2 emissions, CO2 capture and sequestration from power stations, works out with current technology to be ~$70/tonne. That’s equivalent to 80 cents on a gallon of gasoline. Not trival, but not back-to-the-stone-age either.

I find it strange that the technophile conservatarians who tout technology as the answer don’t understand that to get a technology developed, you have to create a market for it by price signals. If the cost to the polluter of emitting CO2 is zero, there’s little demand for technologies to mitigate CO2 emissions.

“a period when prices are spiking is the best time to raise taxes”

Part of the answer is who captures the surplus. Suppose that a $1/gallon price increase is required to achieve the necessary reduction in consumption (“necessary” either in the short run to bring demand in line with supply, or in the long term to reduce CO2 emissions). A dollar increase in market prices or a dollar increase in taxes will achieve that end equally well—but the latter will do more to finance investment in conservation and other public goods.

Counterintuitively, a period when prices are spiking is the best time to raise prices. Since supply is fixed in the short run, the ultimate market price is going to be the same regardless of the tax rate—namely, whatever it takes to bring demand down to supply. So the the only effect of a tax increase is to transfer monopoly rents from producers to the public sector.

Of course, raising gas taxes when there’s negative shock to supply might discourage investment in increasing capacity—altho that’s by no means a sure thing. But if we want to reduce consumption in the long run, that’s an added benefit, not a cost.

That said, the general thrust of your argument is right on the money: We need not pack up and join a commune (after killing off three of our neighbors) in order to control global greenhouse emissions. The currently projected future emissions are disasterous, but based on a relatively straightforward extrapolation of current trends. And as those trends are an outgrowth of a set of particular public and private sector policies—encouraging suburban and exurban housing, shipment of merchandise by truck, multiple trips by single-occupancy vehicles, and so on—that can be changed. I mean, we changed the previous ways of doing things to the present set; we can change back, too.

Yes, people with a stake in the current set of policies will lose out. But if the changes are made consciously and thoughtfully, then the potential losers (most notably, owners of exurban housing) can be compensated in order to buy their cooperation. But without such changes we are most suredly all going to be losers and our grandchildren will look at all of us with daggers in their eyes.

Maybe that’s a good idea, and maybe not. But now that gas is $3.00 a gallon, why is the response not “Good, now demand will decrease and behaviors will change,” but rather “Let’s raise taxes to drive down demand and change behavior”?

I recently bought a Prius. Lots of people I know have done the same. Why do we think “taxes” will do a better job than “naturally high retail prices”?