How Can We Make
Sustainable Aviation a Reality?

  • This is the first article in a series on the future of sustainable aviation.

    How can we make sustainable aviation a reality? That was the topic of a keynote I gave in Brussels last week. And judging by the big turnout, it’s a topic that’s on many people’s minds these days.

  • Globally, aviation accounts for about 2% of CO2 emissions. Consumers are increasingly prioritizing climate change, and are singling out airplanes as a major source of pollution. That’s leading to a backlash against air travel, especially in Europe, where a “flight shaming” movement is starting to affect spending habits and travel patterns. Some government agencies and private companies have even imposed a ban on short-haul flights, requiring their employees to travel by train whenever possible.

    The jury is still out on the actual impact that these protests will have. Flight shaming is a big issue among European voters, and it’s starting to catch on in North America, too. Elsewhere, in the growth markets of Asia and the Middle East, it doesn’t really seem to be gaining much traction. But what’s clear is that we’re witnessing a paradigm shift, as more and more passengers—and governments—are calling on airports and airlines to clean up their act.

  • Personally, I don’t think the flight shaming debate is very productive. Our society fundamentally depends on air travel for many things that we take for granted: how we work, what we consume, how we spend our free time, and—most importantly—how we keep in touch with our loved ones who live far away. Demands for an end to flying aren’t realistic, given the scale of the environmental challenges that we face.

    Instead, let's change the conversation, and focus on the concrete steps that we need to take to decarbonize the aviation industry.

    One option is to simply make flying more expensive by imposing new taxes on aviation. But there are three big problems with that approach. First, unless we apply a blanket global tax, making flying more costly in some countries will just displace traffic to cheaper jurisdictions. Second, if we raise the price of tickets, we’ll basically be dialing back the democratization of air travel that took place over the last 30 years. Aviation will once again become a luxury for the rich, as poorer people are excluded from the flying public. At a moment when populism is on the rise around the world, that would have disastrous political consequences.

    And finally, taxes alone won’t work unless we pinpoint exactly how that money will be spent. Moving forward, the key challenge is to find an approach that’s not just environmentally sustainable, but also socially and economically sustainable. What are the opportunities to do so? And what are the barriers?

    We can break those opportunities down into three categories:

  • Today’s article focuses on the first category: how to build better aircraft.

    In the short term, we need to increase the fuel efficiency of jets, and use more aerodynamic building materials like carbon composites. We also need to increase the use of sustainable aviation jet fuels. That includes synthetic fuels, as well as biofuels that blend petroleum with other fuel sources such as cooking oil, plant oil, and agricultural waste.

    In the long term, we need to change the way we design aircraft, and change the fuel source that we use to power them. Currently, about 200 companies are trying to do just that, by developing electric and/or hybrid powered aircraft. (Click here and here to see some examples.)

  • That’s a quick overview of the opportunities. What are the barriers?

    First off, we have huge sunk investments in the status quo. A brand new jet costs hundreds of millions of dollars. Suppose I’m an airline that bought ten A320s 15 years ago. I’m probably going to want to keep flying those planes for at least a few more decades.

    The second challenge is that we’re not producing fuel-efficient jets quickly enough. Right now, if an airline decides to invest in these new planes, it has to wait for about five years until they’re delivered. Moreover, there aren’t enough producers of sustainable jet fuels, due to a combination of high production costs and low existing demand. In other words: the technology is there, but the critical mass is not. And without that critical mass, it’s difficult to build a convincing business case for sustainable fuels.

  • What about electric aviation? With so much hype surrounding this emerging technology, you’d think that a big breakthrough is just around the corner. Unfortunately, we’re years—maybe even decades—away from a commercially viable electric aircraft, especially one that can fly long distances. That’s because engineers are still figuring out very basic challenges like battery life and how to make these aircraft aerodynamic. While we may see some smaller EVs coming on the market—think aerial taxis—for the foreseeable future, electric aviation won’t be feasible for anything beyond short hops.

    How can we approach these challenges? One option is to impose penalties for operating older aircraft, while at the same time creating incentives to replace them with new ones. Many countries have introduced “scrappage programs” that offer consumers cash to replace older cars with newer, more environmentally friendly ones. That’s helped to reduce CO2 emissions, and it’s given a big boost to the automobile industry. Could we do the same for aviation?

  • Another option is to mandate minimum usage levels for sustainable jet fuels, and create a tax regime that incentives them over traditional fuel. That would jumpstart demand for biofuels and synthetic fuels, and create the economies of scale that are needed to bring down the cost of production and distribution.

    Finally, the public sector needs to invest in long-term innovations, especially in areas that require heavy upfront investments and coordination across different sectors. That money would be best spent on targeted projects with clearly defined outcomes. Developing a short-range electric airplane, and a cost-effective system for distributing biofuels, would be a good place to start.

    Most public discussions about the impact of air travel on climate change have focused on airplanes, not on airports. But quite a lot of our industry’s emissions are produced on the ground, through wasteful and inefficient airport operations. If we really want to decarbonize aviation, we need to build better aircraft and build better airports.

    But that’s a topic for next time.