Thu Mar 8th, 2007 at 09:47:37 AM EST
New Scientist had an article recently about greener ways to fly. We’ve discussed this before, but maybe it’s time to revisit the issue.
We all know the issue: while currently the airline industry produces a small proportion of our greenhouse gas emissions these are projected to grow rapidly and massively in the medium term. Given that high-altitude are several times worse than ground level this means that even if airplane pollution isn’t a serious problem now it will be shortly.
The airline industry points to its record - there have been massive improvements in fuel efficiency in the last few decades - and claims that future incremental improvements will solve the problem.
Unfortunately, the low-hanging fruit are long picked: the industry and technology is mature and we can only expect slow improvements in efficiency, probably far below the rate of growth of industry emissions.
The obvious alternatives have already been debunked: hydrogen is too heavy, low in energy density and difficult to deal with; currently available biofuels aren’t practical for similar reasons and there are serious doubts about the production of large volumes; changing flight practices to be more efficient could save a reasonable percentage, but it’s a one-off saving and introduces more complexity into the already interesting traffic control problem.
The New Scientist article proposes that radical solutions will be required, which would mean extensive research and development and the replacement of the existing jet fleet whose design has been predicated on cheap, plentiful kerosene. Extensive research into active methods of reducing drag was apparently abandoned because they are too expensive when fuel is cheap.
The article talks about flying wings, strut supported wings, use of prop driven engines - which are not only more fuel efficient (if slower) but don’t require kerosene - and the use of drag control systems. All of which require lots of money and time to develop.
Personally, I’m of the view that it’s quite likely that we can develop a set of solutions for air travel that have an acceptable environmental cost and, while more expensive than they are currently, remain accessible to the masses. The rich will always be able to fly.
The shape of the solution is something like:
Discourage flying when it’s not necessary. Why does anyone need to fly from London to Paris? Develop the alternative modes of transport properly.
Accept that flying is the only practical way of moving people very long distances or over long stretches of water.
Send the airline industry the bill for the external costs of flying.
Put in place a programme of incentives and disincentives to encourage the industry to change sooner rather than later: we know that, left to itself, the market will change as late as possible. This would not be a good thing.