Flying is without doubt the worst way to travel when it comes to protecting our environment. The emissions of flying are far greater than any other form of transport, and as it currently stands, they can only be powered by oil – the most harmful fuel source on the planet. Many people wonder though if there are ways to fly sustainably, or if this could ever be done in the future, so we’ve set out to try and find the answer. Could flying ever be sustainable?
How Bad Is Flying For The Planet?
Flying accounts for around 10% of our overall travel emissions and about 3% of the total global emissions each and every year. This might not sound like much, but that’s still over 1.2 billion tonnes of CO2 every single year and comes from just 11% of the global population who are fliers. As it becomes more accessible to more people, you can see how this quickly becomes a growing figure.
Not only does flying product CO2 though, but due to it burning fossil fuels directly in the atmosphere, flying also releases sulphates, nitrous gases, and contrails which all directly trap heat. It also releases PM2.5 particles, which are directly responsible for over 3.2 million deaths each year. This particularly affects poorer countries and cities where air pollution levels are higher.
What About Offsetting Carbon?
Offsetting carbon is now one of the ways in which airlines are making passengers feel less guilty about flying. Most will let you pay a small extra fee to “offset” your carbon and therefore fly carbon neutral. Except you almost certainly won’t be.
First of all, carbon emissions from flying are direct and take fairly immediate effect, however offset programs are retroactive and often fall far behind the expected schedule. So, you’ll still be emitting the same carbon, only you might be helping to get rid of some of it years down the line.
What’s more is the quality of these offset programs vary tremendously, and you can never really know where your offset donation is going. Most airlines won’t make it public where they’re offsetting carbon, so your money could be going anywhere – including any of the less effective programs that often won’t recuperate your CO2 in your lifetime. A study carried out on reforestation projects in South America for example revealed that most projects never deliver anything near the expected carbon benefit.
Providing that you were able to find an airline who is invested in the best possible carbon offset scheme, that was able to provide a quick turnaround on carbon reduction (which is virtually impossible), then you’re still not able to prevent the other harmful substances created by flying that currently have a worse, and more direct impact on human and environmental health.
So at the end of the day, whilst carbon offsetting seems like it’s got the potential to make our journeys carbon neutral, all they really do is clear your conscience and help airlines to escape scaling their flight schedules down.
Perhaps In The Future?
So unfortunately, as it stands flying cannot be and is not sustainable. But what about the future of flying – could there ever be a way for it to become truly sustainable?
There are currently a few methods that could be used to change aviation and make it more sustainable, so what are they?
Sustainable Aviation Fuels or SAFs
SAFs are special fuel blends created using household waste, cooking oils, and plants that are then combined with kerosene to be used for jet engines. Per flight, these fuels have been shown to reduce carbon emissions by up to 80%, making flying a far more viable option.
However, even with an 80% reduction, this still brings carbon levels to around 57 grams per mile travelled, with trains currently being only 14 grams per mile. What’s more is that SAFs are over 3x more expensive than standard kerosene, currently making it entirely unrealistic for airlines to switch to. For SAFs to be effectively sustainable someday, they’d need to further reduce the amount of kerosene used, and be produced at a much cheaper cost.
Electric Planes
Electric planes seem like the most obvious answer – after all, electric cars and train travel are leading the way for more sustainable travel. Whilst entirely electric planes could make flying completely carbon neutral (providing all electricity is generated from sustainable sources), we’re still a long way off that prospect.
As it stands, batteries and electric power in vehicles simply isn’t at the stage it needs to be for flying to work. 1kg of kerosene can currently output around 12,000Wh for a plane, whilst the most powerful batteries are capable of only 250Wh per kg of battery. So, even if you could load up a plane with enough batteries to generate the power for lift off, it’d simply be far to heavy to ever fly. This is especially the case for long-haul flights, where planes get lighter as they go from burning up the fuel. With batteries, this obviously doesn’t happen, making long haul flights pretty much impossible with current tech.
Short haul flights on smaller planes could become electric within the next couple of decades, with airlines like EasyJet currently working on an all-electric plane for up to 186 passengers. This is a good sign that at least some flights could become electric, but unfortunately, it’s only looking like short flights which are easier to switch out anyway, and could be coming far too late. Realistically, without dramatic changes in the next few years, by the years 2035-40 when these planes could become widely used, the damage will have already been done.
Hydrogen Planes
The final strategy that’s currently a potential option to make flying more sustainable in the future is hydrogen. It has the potential to be produced with virtually no emissions at all, and per kg it holds more energy than the fuel that’s currently used. So why isn’t it being used more?
As with every fuel technology for planes, there are roadblocks that make it difficult to implement effectively. Hydrogen requires large storage cells, approximately 4x the size of current plane fuel compartments. Most of current hydrogen is also derived from natural gas during a process that produces CO2, meaning that it’s not currently sustainable. For hydrogen to become a sustainable power source in planes, the world would have to switch to a hydrogen-focused economy where it is produced entirely cleanly and used for a range of purposes to make it cost-effective.
So, could flying ever be sustainable?
Well, certainly not within the next decade, and beyond that, it all depends on which way our economy goes. If we’re able to develop stronger electrical or hydrogen technologies then flying could well become an entirely sustainable activity, which would make long distance travel quick and clean.
So you could say yes, flying could one day be sustainable. However with the surrounding factors, it might be too little, too late, putting more emphasis on avoiding flying as much as possible and focusing efforts on alternative methods that are far closer to becoming entirely sustainable. And that’s if all goes exactly to plan!
