How to be sustainable without changing lifestyle

Introduction

I recently walked the famous “Camino de Santiago” with some friends.

Upon our return, while they opted for a direct flight from Santiago to Barcelona, I chose the train route.

This kind of decision often earns me the label of weird environmentalist. People ask me: “Why do you take trains instead of flights for such a long distance? Flights are faster and cheaper” I explain that I do that for environmental reasons, but questions persist: “How is the train more eco-friendly? Does it really make a difference?”

These questions highlight the lack of detailed information about flight emissions, coupled with people’s preference for the speed and comfort of air travel.

I won’t rehash the debate on whether climate change is real and why it matters. There’s plenty of information available online, allowing everyone to form their own opinion.

This article aims to delve into these questions, emphasizing how taking trains whenever possible plays an crucial role in reducing our personal emissions to a sustainable level without changing our lifestyle.

Flight vs train in numbers

Is flying from Santiago to Barcelona actually cheaper and faster? We can analyse price and duration for the two options.

To have a fair comparison we should not forget that the travel is composed by three different phases:

1. go from start point to airport/train station
2. flight/train journey
3. go from arrival airport/train station to destination

I’ll assume that both the starting point and destination are in the city center.

Flight

Duration

Price

Train

Duration

Price

CO2e emissions

Both flight and train emit CO2 and other gasses that have an impact on climate. Since each option emits a different mix of those gasses it could be difficult to make a fair comparison: to do that we’ll use kg CO2e (kilograms of CO2 equivalent). It’s a unit of measurement used to standardize the climate effects of various greenhouse gasses.

According to Google Flights — which I will use throughout the whole article — the flight emits 76 kg CO2e per passenger, while the train emits 17 kg CO2e per passenger.

Comparison

Flight and train have the same cost, but flight is 34% faster than train.

I would argue that the time spent on the train is higher quality because the seat is usually more comfortable, it’s easier to read, work and even take a walk. This can be personal though, so I won’t use it as the main reason to advocate for trains.

The strong advantage of the train is that it allows us to save 59 kg CO2e.

Put things in perspective

Nice, we can save 59 kg CO2e!

But how much is it? This is a fundamental question. It’s also the reason why most of the people are not interested in the climate change topic. It’s so abstract! If we talk about 59€ or 59 minutes or 59 bananas, everyone has a clear understanding of what they are.

But “kg CO2e”? What the heck is it? And why should I sacrifice the comfort of a faster trip to save some units of that?

To understand how much 59 kg CO2e is, we should first set an order of magnitude with some examples.

All data below are calculated for the 2022 year.

• The world emits 32 billions tons of CO2e (51 billions according to Breakthrough Energy). This means the emissions per capita are around 4.000 kg CO2e.
• China produces 9.9 billions tons of CO2e, the US 4.46 billions, Spain 0.22 billions.
• The emissions per capita are 15.74 tons of CO2e in the US, 7.72 in China, 6.62 in Spain.

Personal emissions

Give those numbers, the decision to take a train instead of a flight may seem irrelevant, but it actually plays a crucial role in reducing our personal emissions (e.g. the emissions we produce directly with our actions) to a sustainable level.

To explain why I started by calculating my personal emissions using the tool provided by Earth Hero app. I only changed the “Flight emission” estimation with the one provided by Google Flights, taking into account all of the flights I took in the last year.

The calculation is based on 6 main categories:

• House: electricity and gas to run appliances, A/C, heating, cooking, water heating, etc…
• Land travel: fuel to run cars, trains, buses, etc…
• Air travel: fuel burned to fly airplanes.
• Food: meat production through livestock — especially cow, sheep and goat — has a big environmental impact. It’s mainly due to the methane emission during the digestion of the animals (aka they fart a lot) and the forests being cut down to make space for livestock.
• Buying new stuff: when things are created, it takes energy to dig up material, make the products and ship.
• Waste: when organic waste decomposes, CO2 and methane gas is created. Incinerating inorganic waste — especially plastic — uses natural resources (water, fuel, metal) and emits lots of CO2.

It turns out I emitted 11.400 kg CO2e in the last 365 days.

It’s almost double the average Spanish citizen. If we split this number by category we can easily understand why.

Category

Emissions (kg CO2e)

The vast majority of the emissions are caused by flights. Without those, I would be well below the national average.

In the past year I was lucky enough to travel a lot and visit many beautiful places.

In total I took 8 return flights:

• 2 intercontinental trips to Cuba and San Francisco
• 6 trips in Europe for tourism and to visit my family in Italy

The return flight to the US alone emitted 1.430 kg CO2, which represents 12.5% of the total annual emission. This should give an idea of the crazy amount of CO2e emitted by planes.

Fair share of emissions

Now I know that I produce more CO2e than the national average but I still don’t know if that’s too much or not.

To understand that, the question to ask is: what is a “fair share” of carbon emissions? In other words, how much can we emit without harming (too much) the environment?

In his book “How to avoid a climate disaster” Bill Gates argues that the only way to avoid the worst consequences of climate change is to get to zero emissions by 2050.

A shorter term goal comes from the United Nations Emission Gap Report. Citing an interesting Vox article: “The latest United Nations Emissions Gap Report shows that to stay on track for an average global temperature rise of 1.5 degrees Celsius, the average biosphere-baking emissions for each human on Earth under the most likely conditions needs to be 2.100 kg CO2e per year, by 2030.”

Again, those are not the numbers I was hoping to see when I started to dig into the topic.

I’m supposed to cut my emissions by 82% in the next 7 years and by 100% in the next 27 years.

Meet the 2030 goal

A brutal approach to meet the goal seems to be to stop traveling, become vegetarian, not buying things anymore and living in a hut, without ever lighting a fire because it emits CO2. While this definitely solves the problem, it would be a pretty big change in my lifestyle and as much as I care about climate change, I’m too selfish to do that. I mean, I could even work remotely from a hut if there was an internet connection, but giving up meat could be a big problem 😀

The “brutal approach” is not for me, but I think there is a way to meet the 2030 goal without completely overturning our lifestyle. In the next paragraphs I’ll explain a possible path to achieve that.

First of all, I split the “Air travel” category into two subcategories: “short” and “long” distance flights. I chose the names for sake of brevity, so maybe they don’t express the idea in the best way.

What I mean by “short” is that there are some flights that — regardless of the distance — can be replaced by other transportation modes without compromising too much on cost, time and comfort. The trip from Santiago to Barcelona is a good example.

On the other hand when the destination is very far away or separated by a natural barrier (e.g. ocean), it’s not realistic to replace it with a different means of transportation. That’s what I mean by “long flight”.

Step 1

I calculated that 67% of my flight emissions are for short distance trips. If we replaced them all with trains — which we assume to emit 78% less CO2e — the total yearly emission would be reduced from 11.400 kg CO2e to 7.394 kg CO2e. Simply moving “Short distance flights” to the “Land travel” category is reducing the total emission by 35% without affecting our lifestyle at all.

Step 2

Today almost all trains emit some CO2e, although much less than airplanes. But there’s an additional factor to consider.

Achieving zero emissions in aviation is very challenging due to the energy density requirements of aviation fuels, the weight limitations of aircraft, and the long distances planes need to travel. While there are experimental electric and hydrogen-powered planes in development, these technologies are still in their infancy and it’s unlikely that they’ll become prevalent in the short-medium term.

On the other hand, achieving zero-emission trains is generally considered easier. This is because trains operate on fixed tracks and routes, which makes it easier to provide the necessary infrastructure for electrification or hydrogen refueling stations.

Actually most of the high speed trains like Shinkansen in Japan, TGV in France, Frecciarossa in Italy and AVE in Spain are 100% electric.

Of course the actual emissions depend on the electricity source they use and the whole lifecycle of the train should be considered, but they have the potential to emit zero CO2e, unlike airplanes.

The same consideration is valid for all short distance transportation (electric car, bus, metro, etc…). So we can say that the “Land Travel” category has the potential to be zero emission.

With this assumption, the total yearly emissions can go down to 5.820 kg CO2. It’s a 49% cut from the initial value and it was achieved without significantly impacting our lifestyle!

It’s a great result, but we’re still pretty far from the 2030 goal of 2.100 kg CO2.

Step 3

To further lower the numbers, we should look at the remaining categories.

Long Flights

I love traveling and in this period of my life I’m in the conditions to do that a lot. It hasn’t always been like that (I took my first intercontinental flight one year ago, when I was 28) and it won’t be like that forever (I doubt I will do 2 intercontinental trips per year if I will have a family or when I will be older). So considering my entire lifespan, it is fair to lower the average number of long return flights per year to 1.

Another consideration is that — although having zero emission airplanes doesn’t seem feasible in the near future — there’s a lot of expectations on the so-called Sustainable Aviation Fuels (SAF). In 2022 SAF accounted for only 0.1% of the overall volume of jet fuel, but the EU Parliament proposed a regulation to increase the minimum share of SAF supplied at each EU airport over time, with the following milestones:

• 2% in 2025
• 5% in 2030
• 20% in 2035
• 32% in 2040
• 38% in 2045
• 63% in 2050

This seems to be a concrete plan so we can take it into account in the calculation.

Considering all of these factors I consider it feasible to reduce the “Long Flight” emissions by 70%. This brings the number down from 2.480 kg CO2e to 744 kg CO2e.

House

Nowadays it’s perfectly possible to have a fully electric home, so we can say that the “House” category has the potential to be zero emission. Again, it’s a potential: it doesn’t mean that if you live in an electric home, automatically you are not emitting CO2e. It all depends on the source of electricity, which is not under our direct control. What we’re doing is opening the possibility to have zero emission, then it’s up to the governments and institutions to do their part.

Food

This is a pain point for me. I could give hypocritical advice to become vegetarian, but I would be the first one not to follow it.

Despite environmental and moral concerns, I like meat a lot and it would be hard for me to give up on it.

There are some way to mitigate the issue though:

• Eating a bit less meat, especially beef and possibly replacing it with poultry. According to the FAO beef production emits 300 kg CO2e per kg of protein, while chicken produces less than 100 kg CO2e per kg of protein.
• Plant based meat is a good option. I tried Beyond Meat and it really tastes like meat. Unfortunately the price is still quite high to make it affordable to everyone.
• Cultivated meat is interesting. This is real meat, but cultivated in a laboratory instead of obtained by killing animals. It has the potential to fix both the environmental and moral issues of eating meat. Some sources report that by 2030 it will represent 0.5% of the global meat supply and it will achieve price parity with conventional meat. If that was the case it could cut the “Food” category emissions immensely.

I’ll be more conservative and assume a 35% saving in this category. In this way it will go down from 1130 kg CO2e to 735 kg CO2e.

Buying New Stuff

To reduce this category we should become more aware of the real usefulness of what we buy, especially online. I don’t consider myself as a compulsive shopper, but it happens sometimes that I buy clothes that I end up never using.

I assumed — quite arbitrary to be honest — a 60% reduction. The emissions go down from 660 kg CO2e to 264 kg CO2e.

Waste

Also for this category it’s hard to imagine how to improve. It depends a lot on factors out of our direct control, like the process items go through when they’re disposed of.

Also here I assume a 60% improvement is feasible. This would cut emissions from 830 kg CO2e to 332 kg CO2e.

Conclusions

The role of trains

Just by taking absolutely feasible actions we were able to reduce the total emission from 11.400 kg CO2e to 2.075 kg CO2. Now we’re under the 2030 threshold of 2.100 kg CO2e.

And the best part is that the impact of these actions on our lifestyle has been minimal.

Using trains instead of airplanes whenever possible played a unique role in achieving the goal.

If you, like me, live in the wealthy part of the world and love to travel, this is by far the single most impactful action you can take to reduce your emissions.

It’s also the only one that gives the possibility of meeting the 2030 goal. This is very important: if we optimize on home energy efficiency, stop eating meat, minimize waste and purchases, but keep using airplanes when not necessary, we will not meet the goal.

I hope this helps to explain why I stress so much on the importance of taking a bit more time to consider our options before booking a flight ticket.

The last cog in the machine

You probably noticed that many times I used the word “potential” referring to reaching zero emissions. As individual citizens, we lack complete control over the entire chain of processes that determine the emissions generated by our actions. We only directly influence the final cog in the machine.

If we take a train but the energy that powers it comes from a carbon plant, our efforts will have a low impact.

It’s understandable to feel helpless: even if we make an effort, we risk seeing no results.

I prefer to think in reverse: if we take a flight or drive a fuel engine car, there’s no way to avoid emissions. It’s gonna happen 100%. While if we make sustainable choices there’s the possibility to improve things.

This means that it’s fundamental for us to do our best in order to keep the last cog of the machine working.

The rest of the machine depends on institutions, advancement in technology, investments and policies. All of those factors are contingent upon the government, which — at least in democracies — is elected by us and is a mirror of the society. So actually we can have an impact on that too, although indirectly.

If you’ve reached this point in the article, I sincerely appreciate your 15 minutes of time and I hope to have conveyed the message that our everyday actions, no matter how small, can significantly influence our future.