In his 2006 book Heat: How to Stop the Planet from Burning, George Monbiot presents a set of strategies to achieve a 90-per-cent reduction in carbon dioxide emissions by 2030. He takes pains to avoid a substantial cut in our standard of living, with one exception: We have to give up air travel.
Mr. Monbiot argues that no technological solution exists that will permit aviation to achieve a 90-per-cent reduction in greenhouse emissions by 2030. Unfortunately, he's right -- in aviation, it is next to impossible to achieve such a drastic reduction so quickly. But his argument is also misleading, because it is highly unlikely that his target will be achieved in other sectors.
Let's start with a question. If two couples want to travel from Toronto to Vancouver over the holidays, and one couple drives a Toyota Prius and the other flies, which burns less fuel? Answer: Neither. The fuel consumed per passenger on a typical flight is similar to that consumed per passenger in a Prius with two passengers travelling the same distance. So aircraft are not quite the gas guzzlers some might think. The reason is simple: Fuel efficiency has been a key driver in aircraft design for the past 50 years. Each time a new plane is introduced, it is more fuel efficient than its predecessor.
The primary emissions from aircraft that contribute to global warming are carbon dioxide and nitrogen oxides. Improving fuel efficiency translates almost directly into reducing greenhouse-gas emissions. So if the industry has been so successful at reducing emissions per passenger, what's the problem? Simply this: The global demand for air travel is projected to keep growing by 4 per cent to 6 per cent a year. Thus, even though aviation is a relatively modest contributor to emissions caused by human activity, it has the potential to become a major contributor.
Fortunately, technological solutions exist. One might assume that improved engines are the key, or that finding a carbon-neutral fuel will do the trick. In fact, aircraft fuel-efficiency improvements have come from better aircraft design and better engines. Moreover, even if we do come up with a carbon-neutral fuel, it will be important to use it wisely. So it's critical to advance on all fronts. We need lighter aircraft with reduced aerodynamic drag, more efficient engines, alternative fuels. We can make some operational changes fairly quickly, but these will provide only a fraction of what's needed.
Possible solutions exist in all of these areas. Bombardier's new C series is projected to produce 20 per cent less carbon dioxide emissions and 50 per cent less nitrogen oxide emissions than comparable aircraft, primarily due to better aerodynamics, increased use of composite materials and Pratt & Whitney's new geared turbofan engine. Beyond this, the blended wing body is a new configuration, similar to a flying wing, that offers the potential for a 20-per-cent improvement. Coupled with hybrid laminar flow control, the reduction in emissions could be as high as 50 per cent. Promising developments in lighter materials, drag reduction, alternative fuels and more efficient engine technologies can be found in research labs around the world.
Significant hurdles must still be overcome before such technologies can achieve the level of safety and economic benefit needed to move from the lab to practical use. To achieve sufficient reductions in aircraft emissions in a useful time frame, it is therefore critical to develop and assess technological solutions quickly. This will require substantial and immediate investment in research and development.
For those who value flying, investment in research to reduce the impact of aircraft on climate change is a priority. If Canada can take the lead, the economic benefits could be substantial. And if you still aren't convinced, a concentrated R&D effort toward more efficient aircraft will also help to keep fares reasonable.
David Zingg is director of the University of Toronto's Institute for Aerospace Studies