Glenn Reynolds examines technological solutions to global warming:

[W]hat if we could reduce greenhouse gases without impoverishing the world? That would be worth doing anyway, because along with those greenhouse gases come all sorts of other nasty substances we're better off without.

That point is catching on, too. Even some environmentalists are already looking to nuclear power as, ironically enough, more environmentally friendly than coal, oil, or natural gas, and we'll likely see more such sentiment in the future.

But nuclear power is just a stopgap - as more advanced technologies like nanotechnology offer much greater prospects via solar energy and reduced energy consumption.

MIT's Vladimir Bulovic calls nanotech a potentially "disruptive technology" in the solar-energy field, offering a complete shift from today's fossil-fuel environment. And famed inventor and futurist Ray Kurzweil projects the current rate of progress in solar power forward and argues, "The power we are generating from solar is doubling every two years; at that rate, it will be able to meet all our energy needs within 20 years."

Solar research is progressing rapidly, and recent research suggests that "quantum nanodots" may offer dramatic improvements, perhaps on the order that Kurzweil predicts. . . .

Ultimately, we're probably better off putting our energies into promoting cleaner, more advanced technologies like these than in trying to get people to reduce the scope of their lives through "hair-shirt environmentalism."

Hair-shirts have always had their fans, but have seldom been widely adopted. On the other hand, most people would like to lead cleaner, better, more efficient lives. Why not give 'em what they want, and help the planet at the same time?

A focus on cutting energy consumption with today's technology isn't going to make much of a difference. Let's work on replacing current tech with something better, instead.

Once the cost of solar power becomes cheaper than electricity generated by burning coal and oil (which might well happen within a decade), the carbon footprint of developed countries will begin to change dramatically. Even if solar power becomes cheaper than the alternatives, given that the cost of solar panels must be borne up front, ultimately the spread of solar power to the developing world will depend on how rich developing countries are in 10-50 years.

If technology is the best route to environmental progress, any environmental reforms that impoverish people are likely to be unhealthy to the planet in the long run.

Last week some commenters wondered why I hinted that radically reducing greenhouse gasses in the present environment ran the risk of impoverishing people. I had in mind two things: (1) our nonsensensical government policy promoting ethanol, which appears to have contributed to a worldwide run-up in food prices, leading to disasters for many poor people around the world, and (2) the stated goals of all three major candidates to reduce US emissions to per capita levels not known here since before the Industrial Revolution.

In the Wall Street Journal, Steven Hayward, who knows a lot more about such things than I do, expresses my inchoate second thought in detail:

The usual chorus of environmentalists and editorial writers has chimed in to attack President Bush's recent speech on climate change. In his address of April 23, he put forth a goal of stopping the growth of U.S. greenhouse gas emissions by the year 2025. "Way too little and way too late," runs the refrain, followed by the claim that nothing less than an 80% reduction in emissions by the year 2050 will suffice -- what I call the "80 by 50" target. Both Hillary Clinton and Barack Obama have endorsed it. John McCain is not far behind, calling for a 65% reduction.

We all ought to reflect on what an 80% reduction of greenhouse gas emissions by the year 2050 really means. When we do, it becomes clear that the president's target has one overwhelming virtue: Assuming emissions curbs are even necessary, his goal is at least realistic.

The same cannot be said for the carbon emissions targets espoused by the three presidential candidates and environmentalists. Indeed, these targets would send us back to emissions levels last witnessed when the cotton gin was in daily use. Begin with the current inventory of carbon dioxide emissions -- CO2 being the principal greenhouse gas generated almost entirely by energy use. According to the Department of Energy's most recent data on greenhouse gas emissions, in 2006 the U.S. emitted 5.8 billion metric tons of carbon dioxide, or just under 20 tons per capita. An 80% reduction in these emissions from 1990 levels means that the U.S. cannot emit more than about one billion metric tons of CO2 in 2050.

Were man-made carbon dioxide emissions in this country ever that low? The answer is probably yes -- from historical energy data it is possible to estimate that the U.S. last emitted one billion metric tons around 1910. But in 1910, the U.S. had 92 million people, and per capita income, in current dollars, was about $6,000. By the year 2050, the Census Bureau projects that our population will be around 420 million. This means per capita emissions will have to fall to about 2.5 tons in order to meet the goal of 80% reduction.

It is likely that U.S. per capita emissions were never that low -- even back in colonial days when the only fuel we burned was wood. The only nations in the world today that emit at this low level are all poor developing nations, such as Belize, Mauritius, Jordan, Haiti and Somalia.

Excessive environmentalism, if actually implemented, would lead to poverty, and poverty leads to death. If a solution is to be found, wealth — and the technology that wealth buys — will play a big part.