Every silver lining has a cloud — or so we are told.
Climate analyst Jesse Ausubel is getting a lot of press with his new, controversial, deeply flawed study, "Renewable and nuclear heresies" (available here with subscription, but you can get the main points from this 2005 Canadian Nuclear Association talk and the accompanying PPT presentation).
He says ramping up renewables would lead to the "rape of nature." His study concludes:
Renewables are not green. To reach the scale at which they would contribute importantly to meeting global energy demand, renewable sources of energy, such as wind, water and biomass, cause serious environmental harm. Measuring renewables in watts per square metre that each source could produce smashes these environmental idols. Nuclear energy is green. However, in order to grow, the nuclear industry must … form alliances with the methane industry to introduce more hydrogen into energy markets, and start making hydrogen itself … Considered in watts per square metre, nuclear has astronomical advantages over its competitors.
Uh, no, no, and no. Jesse popularized the notion that the economy has been decarbonizing for many decades (see Figure 2 of the PPT). This has led him to make a bunch of serious mistakes.
First, he basically thinks decarbonizing is all but inevitable with some effort on our part (i.e. pushing nukes and hydrogen hard). But if you look closely at Figure 3, you’ll see that in the last few years we’ve been "recarbonizing" — coal use has been soaring while natural gas use has stalled. (Also, even Ausubel’s historical decarbonization was an essentially meaningless trend, since it did not stop absolute carbon levels from soaring dangerously in recent decades.)
Second, if decarbonization is all but inevitable, then global warming will mostly take care of itself. He doesn’t come out and say this, but his talk never discusses the threat of climate change, which is much more likely to rape nature than renewables.
Third, he thinks hydrogen is the inevitable future. In fact it is a dead end — the energy carrier of the future is electricity (PDF), hopefully with cellulosic ethanol. Sorry, Jesse, no one in their right mind would use nuclear power to make hydrogen, especially since fuel cells just convert the hydrogen back to electricity — wasting some 75% of the original electricity and requiring you to buy expensive electrolyzers, hydrogen infrastructure, and fuel cells.
His fourth mistake, the land analysis, which got all the recent attention — "Renewable energy projects will devour huge amounts of land, warns researcher" — is the most serious, I think.
First, off, the most important type of new renewable energy is wind power. The key point with wind is that the vast majority of land covered by the wind turbine is still usable for farming or other purposes. As John Turner of the National Renewable Energy Laboratory points out, "The footprint for wind is only 5% of the land that it covers." Some wind turbines can also be placed at sea, where "land" is plentiful.
Second, just as wind power allows dual use (you can still farm around it), so does solar — you can put photovoltaic panels on roofs. Not sure what you can do at a nuclear plant besides make power (unless you’re Homer Simpson).
Third, yes land is a problem for biofuels, but even then the most serious biofuels researchers are pursuing multiple uses for biomass — biorefineries that make electricity, liquid fuel, and feedstocks for industry. I doubt bioenergy will be more than 10% to 20% of the total global solution to climate change, unless someone cracks the micro-algae puzzle.
Fourth, Ausubel fails to distinguish between the United States and the world as a whole. We are one of the few countries with a large amount of excess arable land — so we can probably get more fuel and power from bioenergy than most other countries. Here is what one study (PDF) finds:
We have about 450 million acres of cropland in the United States with approximately another 580 million acres of grassland pasture and range. Forest use land totals about 640 million acres, for a total of nearly 1700 million acres of land potentially available to produce feedstocks for ethanol production. Approximately 40 million of these acres are in the Conservation Reserve Program, a government program designed to take more fragile lands out of conventional grain or oilseed production. If we devote only 100 million acres to energy crop production and obtain an average of 15 tons of biomass per acre per year on that acreage and then convert that biomass to ethanol at 100 gallons per ton (approximately 85 percent of the theoretical maximum yield), we will produce 150 billion gallons of ethanol per year. This is equivalent to about 75 percent of the gasoline we currently use, taking into account ethanol’s lower energy content per gallon.
Finally, Jesse never talks about the constraints to nuclear power, but in fact, there ain’t enough uranium for nuclear to be the dominant solution to global warming — indeed, even one "wedge" of nuclear would be monumentally difficult, as I have previously noted. The Keystone Center Report, "Nuclear Power Joint Fact-Finding (PDF)," finds that one wedge requires building "14 plants each year for the next 50 years, all the while building an average of 7.4 plants to replace those that will be retired," and on top of that:
For nuclear power to be even one wedge we would need 10 Yucca Mountains to store the waste.
We would have all of the proliferation risks associated with spreading nuclear power across the planet.
And the power isn’t cheap: 8.3 to 11.1 cents per kilo-watt hour.
And we need 8 to 10 wedges to avoid climate catastrophe — so it’s silly to say any one power source is the solution. At best, if we tried incredibly hard, nuclear might — might — be close to one wedge. Wind might be a wedge or more. Other renewables might will comprise a wedge. Energy efficiency could be three or more wedges. Carbon capture and storage is probably at most one wedge. I lay out my scenario in Hell and High Water.
Avoiding catastrophic global warming is the most serious problem of our times. If current "decarbonization" trends continue, we will rape the planet. Jesse Ausubel’s flawed and contentious analysis does not advance the discussion, but rather throws smoke in people’s eyes. It will no doubt be widely quoted by Global Warming Denyers and even more by Delayers — those who argue we must wait for new technology before acting. In that sense, the analysis is now part of the problem, not the solution.