When climate change is the reality, our grandchildren will look back in horror at how we travel today

Until recently I thought I was a pretty eco-friendly human being. I don’t eat much meat, my flat is fuelled by green energy, I cycle to work and don’t own a car. I even wash and recycle baked bean cans for crying out loud. As far as I was concerned I had an LED-lit green halo circling my head.

But then I did a carbon footprint calculator. It grilled me on my lifestyle, what I eat and what I buy, and it turns out my annual carbon emissions are 50 per cent higher than the recommended amount. The seven-tonne elephant in the room? Air travel.

My results, formulated using WWF’s calculator, don’t take into account business trips but do include the four leisure trips I took over the last twelve months (three short-haul to Europe, one to the US). Those flights alone - totalling around 24 hours in the air - account for half of my annual carbon emissions. Half a year’s carbon output in one day. Whichever way I try to spin it, that doesn’t sound great.

Actually there is one way to spin it. Compared to fellow Brits I’m not particularly excessive in the number of holidays I’m taking per year. According to ABTA the average number of holidays taken in 2017 was 3.8 per person. Hands up, I didn’t have to use up my 3.8 allowance with overseas trips, but when budget flights are often cheaper than domestic rail travel, and when there’s so much of Europe to see, a hop across to the Continent seems to be a perfectly acceptable option.

I fear that my line of reasoning won’t fly in future decades, when the projections of global warming become a reality - something that we, and many countries around the world, received a sobering glimpse of this summer. In the way that we have woken up to the environmental impact of single-use plastic waste, diesel fumes, and the health impact of cigarettes, I wonder if my unborn grandchildren will look back in horror at the way we travelled in 2018.

It’s an awkward subject. Awkward because travel is such an emotional thing; affordable aviation has brought the world to our fingertips and it is on these holidays that we form our most cherished memories. Travel is no longer a privilege; to the class of 2018, it is a right. It’s also impossible to not sound like a ‘greensplainer’ if you’ve boycotted air travel, or like an awful hypocrite if you continue to fly but have a niggling voice in the back of your mind that something needs to change.

But sometimes these awkward conversations have to be had. And my word, this conversation with my grandchildren toward the end of the 21st century will be uncomfortable.

The first thing to surprise them will be that, back in 2018, the environmental impact of air travel was no secret. Jet fuel accounts for 2.5 per cent of humankind's total carbon dioxide emissions. The aviation sector's contribution to global warming doubles when you include non-CO2 greenhouse gases, like nitrogen oxides. Or to put it more crudely (ahem), planes burn up around 5 million barrels of oil every day.

So why on earth was this allowed to happen, they will ask. I will tell them that, back then, it was in nobody’s interest to do anything about it. Flight tickets were cheap and we all understandably wanted to see the world. As a result there was very little political motivation for governments to proportionally tax jet fuel and make flying less affordable. So the aviation industry had zero motivation to invest in pricier biofuel alternatives when kerosene remained artifically affordable. Air travel stayed cheap and the vicious circle was complete.

Surely the answer, then, is that we ought to come together and boycott flying, embrace domestic travel, or simply find other things to spend our time and money on that doesn’t wheeze tonnes of greenhouse gases into the atmosphere? Sustainable travel expert Professor Stefan G?ssling tells me that this isn’t going to happen.

“Humans are just not altruistic. We will not change our behaviour at the perceived disadvantage to ourselves to benefit others. This applies to aviation, we will not change our travel patterns because we know it’s going to impact others,” he said.

However, in G?ssling’s opinion there is another way to bring about change. At the ballot box.

“What we might be willing to do is vote for politics that will help to set the stage differently for everybody,” he said. “The easiest way of tackling the problem would be to introduce an aviation tax of some sort which is proportional to energy use and which makes it commercially more interesting to develop biofuels. Voters should support environmental taxation simply because it will force the sector to rethink biofuel alternatives. As it stands the incentive is missing.”

Hearing this, the philosophy graduate in me pipes up and wonders if there is something ethically dubious about pricing people out of the skies. Should experiencing the far-flung corners of our planet really be something for the few, not the many? G?ssling tells me this is unrealistic thinking.

“We live in a capitalist world. Capitalism means that not all people have the same access to resources. So long as we have capitalism you cannot argue that we cannot steer consumption of environmental resources through monetary based approaches.”

Something I suspect my grandchildren might ask at this juncture is how - at the very least - did we punish those compulsive flyers, who rack up not just hours but days and weeks of time in the air per year. I will shuffle my feet and tell them that in 2018 frequent flyers were not reprimanded. In fact, the opposite. They were upgraded on flights and given monetary incentives through frequent flyer schemes.

Dr Doug Parr, chief scientist at Greenpeace, tells me that we should be focusing on taxing these frequent flyers, not average passengers. “Growth must be limited, ideally by a demand-control measure such as the frequent flier levy, which penalises binge flying without pricing poorer people out of the skies. If that sounds radical, remember large swathes of the fishing industry, for example, have already had to go through that process.”

Perhaps the final blow, in this awkward Christmas Day discussion with my grandchildren, will be when I tell them that in 2018 I was part of a minority - a tiny minority - that actually participated in flying at all. Only 3 per cent of the global population boarded a flight last year, and only 18 per cent of planet Earth's population have ever flown.

We, the 3 per cent, are the trio sat in a room of 100, chuffing away at cigars while the rest inhale the smoke. And it’s addictive stuff. According to the International Civil Aviation Organization the number of air passengers will rise from 3.9 billion in 2017 to 7.2 billion by 2035. With that, the damaging environmental impact of flying will only continue to grow.

So what we can do? We can deny mankind's impact on the warming of the planet's climate system, but I suspect the annuls of time won't treat that approach with a great deal of respect.

Alternatively we can reduce the amount we fly. We can support politics that advocates clean aviation, developing biofuels and electric passenger planes. We can carbon offset our flights (through a tested, reputable scheme). We can support the few airlines like KLM, United and Singapore Airlines which have already started testing biofuel flights. We can fly non-stop whenever possible, as take-off and landing are the biggest sources of plane fuel emissions.

It all feels a bit dizzying to know where to start. So first thing’s first, we can have that awkward conversation - whether with a friend, colleague, or ourselves via an imaginary future relative - about whether we have our heads in the sand about the true environmental impact of our flying habit.