We were out for an after-work beer, and one of my colleagues asked why flying contributes such a big part of the ecological footprint. He described his frustration that, no matter how much effort you make saving CO2, as soon as you have one flight journey, you have the impression it was all for nothing. That's right, and, yes, that's frustrating. Even when you travel as ecologically as possible, one medium-haul flight is enough to spoil your statistics.

We saw this as an occasion to write an article about the CO2 footprint. Our research amounted to quite some material, so be prepared: This is going to be a long one!

How to determine your CO2 footprint

We searched the internet for different ways to compute the CO2 footprint, because there is no single correct way to do it. Firstly, the country you live in matters: Depending on that, certain values are used due to different emissions of different countries. The WWF offers  CO calculators for different nations, for example for UK, Germany and Switzerland. The webpage CO2logic.com offers the service to determine emissions for the different areas of life (traveling, living), to get an idea which part causes most (or least) of our CO2 emission. Other calculators in German language are offered by  Brot für die Welt and endlich-wachstum.deCarbonglobe.com is an example for U.S. citizens. Each of the tests asks the questions a little differently, and you get a lot of information and ideas about possible improvements. All in all, the tests are quite similar and agree on the main aspects contributing to CO2 emissions.

Earth Overshoot Day

An interesting concept we wanted to address briefly as well is the Earth Overshoot Day. It represents the day of the year at which mankind has used up all the resources Earth can supply and recover each year. In the year 2018, this day was on August 1st. On that webpage, it is possible to compute your own personal Overshoot Day. We tried it out and discovered again: Air travel has a large impact!

The problem about flying

The problem about air travel is that it is a luxury good. Even though flying has become a lot more natural in recent years, also due to low-budget airlines, the majority of the global population does not travel via plane, has never seen the inside of an aircraft and will never in their whole life. The most important point is that the footprint considers the sum, i.e. all the CO2 that ever got into the atmosphere.
Air lines like to tell us that they are only responsible for 5% of all CO2 emissions and do not constitute the largest sector. But this is exactly where it's worth to look a little deeper:  5% - not counting all the other traffic. Only one single traffic sector, and, as already mentioned, a luxury. For such a restricted good, 5% are a astonishing lot!
In order to motivate you again to try and decrease your footprint's size a little: Even though your personal change in relative terms (percentage) does not seem big, the change itself (the magnitude) is just as much as for a person who makes the same effort and does not fly. I hope that this sounds a little more motivating. Even if you really shouldn't drop your flights, maybe you can look at your CO2 footprint with and without air travel, just to get an idea about how much flying actually matters!
And maybe you will reach the conclusion that it is worth to forgo flying every once in a while. Especially for short distances, which are doable as well by train or bus.

Offsetting CO2 emissions

I was asking myself the question whether it's possible to somehow undo the CO2 emissions you are "guilty" of. In the back of my mind, I had the label 'CO2-neutral', picturing a forest where a lot of carbon is safely bound in biomass. Maybe somebody is planting trees to make up for my flight?

Indeed there seem to be several service providers who promise to offset CO2 emissions caused by companies and private individuals. Among them there are names such as myclimate, carbonfund.org and atmosfair. The latter is maybe known to those of you who recently booked a Flixbus ticket. I thereupon wanted to have a closer look at the company atmosfair. What exactly is this company doing with the offset payments? To me it sounded like an analogy to the indulgence payments of the Early Modern Age to the catholic church, where only the conscience of the "sinner" is is silenced, and some organization is enriched illegitimately.

The website very correctly states that “If it is not possible to avoid CO₂ emissions, at least measures should be taken in order to reduce them as much as possible.” Atmosfair offers a service called "offsetting" CO₂ emissions. This means that emitted CO₂ is saved elsewhere, e.g. by promoting efficient energy production in developing countries.
One should keep in mind that no CO₂ emissions are being undone by this concept. Instead, CO₂ is saved elsewhere by using e.g. renewables instead of fossil fuels. This means that most measures do not remove CO₂ from the atmosphere but only help to emit less. However, this does not make it wrong or incorrect, because the CO₂ is still saved. The result is the same.

One way to actually remove CO₂ from the atmosphere is by binding it in biomass, e.g. in forests. The problem about planting a forest for compensating emissions is, that it must not be chopped down (and burned) again right away if CO₂ is supposed to stay bound. A forest would have to exist for many years and grow biomass, which is being harvested several times to replace fossil fuels. Then, the forest could have an effect on the  CO₂ concentration in the atmosphere. This is quite complicated! According to atmosfair, the time it would take for the forest to have such an effect is around 50 to 100 years. This is, especially from the entrepreneurial point of view, a very long timescale. Another problem is the following: If you protect a piece of rain forest, another piece of forest is most probably chopped down instead. Nothing changed in the CO₂ budget. It isn't so easy to undo CO₂ emissions. This is also how atmosfair justify why they do not have these forest projects.

At the moment, research is also being carried out into other ways of permanently removing CO₂ from the atmosphere. First it would have to be possible to extract the CO₂ efficiently from the air. Then the question is: Where to put it? One would need a safe deposit from which the CO₂ cannot get back into the air. In any case, research has not yet reached the point where this process can be mastered almost efficiently.

One idea I came across during my research is biochar: Biochar can be made from any kind of biomass, i.e. from wood, but also from leaves, trash and dung. It is produced by heating in an oxygen-poor environment, similar to the normally known charcoal. The biochar is put into the uppermost soil layer where it improves plant growth. You might have heard about this effect already under the heading Terra Preta. The important point is now that the carbon remains stable in the soil. Since there is less oxygen available in the soil for chemical reactions, the carbon can hardly react to CO2 gas and find its way back into the atmosphere.

Websites about negative CO2 budget (= removing CO2 from the atmosphere)

There are some attempts towards technologies to bind CO2 from the air, e.g. here and here.
Information about biochar can be found at carbonzero.ch (in English). There are also some interesting pictures showing the effect of biochar as a fertilizer. The project is linked internationally with the International Biochar Initiative, the IBI. This is an NGO based in the USA, promoting biochar.
Well, I will think of compensating my next flight at least in part with a donation to the IBI.

"Studies have indicated that the carbon in biochar remains stable for millenia, providing a simple, sustainable means to sequester historic carbon emissions that is technologically feasible in developed or developing countries alike. The syngas and excess heat can be used directly or employed to produce a variety of biofuels."

- carbonzero.ch

Some concluding remarks

We learned a lot during our research about the ecological footprint and CO2 offsetting, for example:

  • It's definitely better to save CO2 in the first place compared to offsetting, so: Flying only makes sense when it's definitely necessary!
  • Clothing, electronic devices, etc. should be bought second hand if possible instead of buying new.
  • It makes a great difference when you buy seasonal food with less animal products.
  • Biking instead of driving or taking the bus is not only good for the climate, but also for your personal fitness!
  • Saving energy and heating costs also makes your wallet happy 😉 (I don't know if this is actually an English expression but you get the message I guess xD)

We actually started this blog in the first place for this reason, to make others aware of these issues and share our personal experiences with you! And this article about CO2 is so to speak the main motivation why we brought it into existence. We try our best in our every day life (and in our jobs as well) to save CO2 , but we learn new things all the time - also by writing this article. And we want to share these insights.

We will have to achieve a negative CO2 budget until the mid-century to achieve our 1.5°C warming goal (IPCC)

Only while writing this article, I realized how difficult it will be to achieve this goal. As previously stated, the technological approaches to removing CO2 from the atmosphere are far from being efficient. Much more research should be done in this direction! The IBI can probably really use my donation, haha. Until then, it's worth living as CO2-efficiently as possible, even if you often have the feeling that you can't really achieve anything as an individual. However, the general awareness of environmental issues has increased a lot in recent years, which gives me hope that something will actually happen. Individuals who lead by example and make others aware of these issues can have an impact on many. I hope this motivates you to look at your personal CO2 footprint and perhaps try one or two strategies to reduce it.

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