The air flight industry is talking about sustainability more and more, but do they walk the walk? Recently, the International Civil Aviation Organization reportedly blocked scientists from its Twitter page for sharing valid criticism, which is not what you’d expect from an industry that actively wants to reduce its emissions.

That’s not to say that progress hasn’t been made, because it has, but critics are rightfully questioning whether that progress is sufficient or not. Let’s have a look.

Image credits: USDA.

We all like to travel from A to B quickly — and, given today’s technology, there’s no real substitute for flying. But whether we like it or not, planes are an important contributor to greenhouse gas emissions. The airline industry produces between 2-3% of all man-made CO2 emissions, and the sector is increasing rapidly. The number of people flying has doubled from 2 to 4 billion in the past 15 years and shows no sign of slowing down.

If global aviation was a country, it would rank in the top 10 emitters. Global aviation emissions are projected to rise by 70% from 2005 to 2020, and by a further 300-700%. Many airports around the world are undergoing or planning extensions, which would further exacerbate this increase (although carbon-neutral airports are also becoming a thing).

So what is the aviation industry doing, and what can it do?

According to the Environmental Defense Fund, there are 4 main things that companies can do:

• fly more efficient aircraft,
• use new technologies to set more efficient flight paths and reduce delays,
• use sustainable lower-carbon alternative fuels, and
• invest in emissions offsets within or outside of the aviation sector.

While plane efficiency has improved dramatically in the past decades, the trend has stalled in the past few years. Especially in the US, where regulation has been relatively lax, little progress has been made recently — despite the fact that the Environmental Protection Agency concluded that CO₂ from aviation contributes to pollution that endangers public health and welfare, which legally requires a framework to reduce emissions.

Improving efficiency also requires companies to renew their fleets — which of course, costs a lot of money, and some companies have been more willing than others to do.

Reducing delays and implementing more efficient flight paths are constantly being improved and finessed, but there’s only so much that that can do — at the end of the day, you still have planes flying and consuming fuel and generating emissions. Naturally, the way to address that would be by developing alternative fuels. However, there’s no global standard to produce and measure the efficiency of biofuels, and studies have shown that, most of the time, biofuels are surprisingly ineffective — we don’t really want to cut down forests for biofuel crops, that would be simply offsetting the problem. Simply put, alternative fuels for aviation, while an area of active research, are miles away.

The other approach, if you can’t or won’t reduce your emissions, is to invest in sectors that would offset your emissions. They could, for instance, support the development of renewable sectors in developing countries or finance reforestation (that’s still a simplistic view, but you get the idea). Several organizations such as the World Wildlife Foundation (WWF) support a “market-based measure” that would require airlines to pay a fee for the growth of the carbon they emit on international flights. This type of policy has already been implemented in the European Union with notable results. It creates a financial incentive for companies to reduce their emissions.

At the end of the day though, without a carbon pollution cap or some form of taxation, it’s unlikely that substantial change will occur. Naturally, most of the aviation industry is opposed to such policies and in most cases, governments have failed to deliver healthy regulation. The big silver lining is the Carbon Offsetting and Reduction Scheme for International Aviation, or CORSIA — an emission mitigation approach for the global airline industry, developed by the International Civil Aviation Organization (ICAO). However, CORSIA has proven to be a very delicate compromise between all parts involved and is not nearly as stringent as EU regulation for instance.

Lastly, it should also be said that we, as passengers, also have a responsibility. If you fly from London to New York, you generate roughly the same level of emissions as heating a home for an entire year. We all love vacations in faraway places, we love to fly to conferences and events — but it would be best if we could be a bit more conscious about our flights. Even if you work really hard to take the bus or bike to work, even if you reduce your meat consumption, all that hard work can be invalidated by a single trip. We can also push politicians and companies to adopt more responsible policies and try to push. At the very least, we should be aware of these issues.