Bio–Jet Fuel Struggles to Balance Profit with Sustainability

[xchrom]

http://www.scientificamerican.com/article.cfm?id=bio-jet-fuel-struggles-to

DURBAN, South Africa—My share of the carbon dioxide my flight to Johannesburg emitted over 15 hours amounted to 1,391.3 kilograms, according to the helpful information provided by South African Airlines. Add a dollop of 53.8 kilograms of CO2 for the jet jaunt to Durban and you can see that the aviation industry—and the Durban climate talks—have an emissions problem.

In fact, flying now accounts for some 2 percent—and growing fast—of global greenhouse gas emissions, although the industry has pledged to stop that growth by 2020. According to the aviation industry, a full 80 percent of the roughly 650 million metric tons of CO2 annually emitted by aircraft are from those flying more than 1,500 kilometers (like my trip from New York City to Durban) for which there is no alternative mode of practical transport. And, given the energy density of kerosene, there really is no alternative to liquid fuel either—with the exception of lightweight solar-powered drones, electric planes cannot get off the ground. As for hydrogen, it is hard to carry enough of it and still have space for passengers, too.

That's why the U.S. military, a slew of airline companies, Boeing and others have invested heavily in jet fuel made from plants—the oils provided by weedy camelina or hardy jatropha shrubs or even algae. The fuels have successfully passed all trials—even delivering more thrust per gallon—and have now entered regular commercial use in the U.S. and Europe, promising to cut CO2 emissions by 80 percent, albeit at a premium price. The U.S. Federal Aviation Administration is giving out $7.7 million in contracts to such jet biofuel–makers.

[saras]

1. Commercial flying is not sustainable. Neither is military, but they don't give a shit.

At some point in the near future, the land to produce biofuel for jets will be competing with the land needed for food for humans.

The best plan would be to remove all public support from the airline industry and see if they can survive on their own. But we should stop giving them free airports and highway work and invasive airspace over others. They can buy all this stuff on the 'free market'.

[Bob Wallace]

2. Not quite correct...

Some biofuel crops can be grown on lands unsuitable for food/fiber crops.

Switchgrass is a plant that does quite well on land which is unsuitable for normal agricultural uses. It has low water and fertilizer needs, sequesters carbon in the soil with its extensive root structure, and improves the soil making it useful for food production in the future.

Algae is particularly interesting because it can be grown on the worst of land.

The best solution is likely to move medium length travel to electrified high speed rail. But we're still going to want planes to cross oceans and continents.

[NickB79]

3. Land unsuitable for agriculture is usually called "wilderness"

And the land we could plow up to plant switchgrass on was, a long time ago, referred to as "prairie". I hear it was once a really beautiful place. It was populated by these things called "wildlife", which unfortunately get chewed up when all that switchgrass is cut and harvested.

[kristopher]

4. How do you distinguish between wilderness and all other land-use?

Are the only two land-use categories "food/fiber crops" or wilderness?
Your distinction seems purely arbitrary and rather maliciously intended.

[Bob Wallace]

5. Well, it was all wilderness at one time....

Now some of it is land that is burned out from cotton agriculture and land that has been grazed to death.

Fact is, there are too damn many of us on this planet and until we manage to drop our population levels significantly we're going to be using a lot of the available land. You might not like that. I'm not really happy about it. But it's reality and sometimes reality bites.

[plcdude]

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