POSTED 25.07.2022

Text and image: Miina Hujala

How can one estimate the impact of one’s own actions in terms of sustainability? Here I am looking at especially the effects of travel methods and carbon calculations.

When thinking about the ecological or environmental impact of any kind of activity, getting a clear picture inevitably involves a lot of parameters and can be in a very total sense impossible. (I want to note that ‘ecological’ and ‘environmental’ are a bit different as terms but I use them both here as inclusivity). As a simplification, it is always notable that the more we consume anything the more effects will be caused. But there are huge differences between what we consume and the effects they produce. 

I have been conducting a project that aims at finding alternatives to flying  – Land-Based Long-Distance | Trans-Siberian train route (NOTE:The project that was cancelled in 2022 was planned as a platform that would explore long-distance group travelling and was to linked to art residencies. It was utilizing the trans-siberian train connection to east. Travels were done in 2018 and 2019.)  I got engaged with the issue of travelling – mobility and the effects of it to the climate – because the main impact of my personal carbon footprint (things that I can affect) came previously from travelling and from especially long-distance flights.

There are several providers of carbon footprint calculations that give a way for an individual (and in some instances for an institution or a business, like Julie’s Bicycle or WWF Green Office for instance) to assess the carbon emission output of their activity (facilities, practice etc.)

These calculators are tools that provide awareness of the impact of personal actions and choices and when trying to address the question of how one could act climate consciously – they help out in pointing to different areas of daily life that can be thought of in the light of climate actions and reducing the carbon impact.

As a start, I made some calculations of my carbon footprint, using the calculators found online in Finland because they take into account most accurately the national/regional variables.

The results were: > 3000 kg / CO2 

and > 5900 kg / CO2 

(In English, The Finnish website for calculator list by the Finnish Environment Institute SYKE.)

I also used one international one: where the result was 6500 kg / CO2.

I will use larger amounts as the calculators are more detailed.  I’ll use the approximate value of 6000 kg / CO2 for a round number and based on the Finnish calculator that takes into consideration the national possibilities and situation better. 

Note: The average Finnish person’s carbon footprint is 10,300 kg / CO2 based on Sitra’s estimate [Sitra is the Finnish Innovation Fund, connected to the parliament that has had sustainability as one of its focuses.]

Therefore, to return to the issue of flying, in comparison: 

one person round-trip flight from Helsinki to Tokyo = 4,893 kg CO₂

(with calculator from

one person round-trip flight from Helsinki to Tokyo = 2828 kg CO2 

(with calculator from

Thus, one round-trip adding to almost the entire amount of my annual carbon load depends on the calculation. (It is also noticeable that even though these both online calculators have a “green agenda” they provide very alternative results; an issue ! will also address later in the text a bit.)

And to point out that in order to stay under the 2 degrees limit (to avoid global warming that exceeds that) my footprint should be under 2500 kg / CO2 per year by 2030.

(This is also from the website of the Finnish Fund Sitra, accessed 7.4.2021. The Finnish Environmental Institute SYKE which provides the ‘ilmastodieetti’ calculator states a level of 3000 kg / CO2) but it of course it should be as small as possible.)

Before going further on the calculations of travel methods I’ll list here some of the other factors we need to change and that we can choose in part of our daily lives besides mobility methods: to use of renewable energy (as electricity, in warming our houses and in our cars), eating less meat and dairy products and in principle all in all consuming less.

But here in this text I am pondering that when flying – especially long-distance with other source of energy than fossil fuels (like hydrogen) is still a distant prospect – that how could we still continue to travel using alternative modes available. Like trains and the Trans-Siberian route when/if I still want to go to Japan. (More about the Trans-Siberian route and its calculations can be found in another blog I have. And two articles of the hydrogen as the flying fuel:, in English, accessed 7.4.2021 and, in Finnish, accessed 7.4.2021.)

As we are in the need to reduce climate warming emissions fast, I think acting on the situation present is urgent on many fronts. Finding alternative solutions to flying is the one way if I want to continue to travel at the same time aiming to reduce the carbon emissions.

Thus to get a clearer picture of what the effects of my mobility are, I have searched a way to compare the climate effects of travel. I have looked at various online carbon emission calculators that provide a very alternating field of results of the emission load of what one trip amounts to.


When looking at flying it most often stated that it causes only 2% of total global CO2 emissions (, accessed 7.4.2021). This is just a part of the picture as producing airplane fuel kerosene will also contribute to the overall utilization of fossil fuel more due to the fact that only 5-8% of raw oil can be processed to kerosene, the rest to be left to process to other products. (Here in this online article in Finnish science writer Risto Isomäki lists things that need to change for aviation to continue, the title being very optimistic that flying doesn’t have to end if the emissions are brought under control, accessed 7.4.2021). Focusing on just the percentage of the aviation emission load is unbalanced as an act as we look at the possible ways to effect change on a personal level. Meaning that: As I wanted to focus on acts of what I can do, personally and with the choices that I can take, avoiding flying does contribute hugely to my carbon emission effects, lessens my load, so to speak. There is the psychological element involved in trying to find empowerment in the crisis, to do something, take responsibility. (Without neglecting the important fact that not all choices are possible for everyone, and in every situation.)

Traveling is something that I want to do, and is part of the things that I choose to do, therefore not willing to opt out of it entirely is a personal preference (which of not-doing of course could be an option as well). But my perspective is not about the inability to do something, but on finding alternative ways of doing, with different – here in this instance climate conscious – parameters involved. Therefore, I started to look at how I could assess the carbon impacts of travel, and I took as an example some routes that I have taken previously, to Berlin in Germany, Lofoten Islands in Norway, and Venice in Italy. (Limiting thus in this text the scope to Europe, but as I have the ongoing project focusing on east-bound land-based long-distance travel I will through it explore further extensions of this subject matter.)

1st example:

One person round-trip to Berlin can be calculated thus:

By Plane: Helsinki – Berlin – Helsinki 674 kg / CO2

Helsinki – Berlin – Helsinki 444 kg / CO2

Here as well, as in the lifestyle estimates previously, it is quite obvious that there are differences in the calculation models and results, even though both of these are websites that offer a service of a compensation of the emissions.

As for instance the International Civil Aviation Organization calculates the same trip to amount to 250 kg / CO2. But it would be said that one variable comes from that the radiative (“caused by non-CO2 warming pollutants, such as water vapour, aerosols and nitrogen oxides”) impact of flying is not taken always in consideration in the calculators – that necessitates that the amount in some models should be at least doubled (, accessed 7.4.2021).

As not all calculations take the radiative impact in consideration, and also that it is safe to say that the optimal would be that planes would fly with full capacity (which is not de facto the case in all flights), therefore variables in the allocation of the personal emission load per seat evidently is affected by these. But based on these results broadly I would estimate that a 400 kg / CO2 round trip from Helsinki to Berlin with a plane could be somewhere in the approximate accuracy.


Then we go on thinking about what a land-based option would look like for the same trip and step on the first “hurdle” on this particular route. From Helsinki, we usually need to get across the Baltic sea. (Evidently there are options of going though the Swedish border at Tornio-Haaparanda in the north or taking a ferry Vaasa-Umeå, as also travelling through St. Petersburg in Russia to reach Baltic states and forward. I welcome these options and understand the problems with them as well; like the visa requirement in Russia or the very long ‘detour’ north when aiming to travel south. Travel time will necessarily be always longer in the land-based methods compared to flying, therefore calculating that as a factor is very dependent on what one perceives the trip is about and how to prefer different variables.)

But when travelling with land-based methods the most “direct” way, we thus need to add the possible ferry trip’s emissions.

To address this, I’ll use the estimate from here (–%C2%A0mennäkö-meren-yli-lentäen-vai-laivalla accessed, 7.4.2021) that uses Lipasto’s data. Lipasto is a calculation system for traffic exhaust emissions and energy use in Finland.

Based on that the ferry from Helsinki-Stockholm (one-way) 70kg / CO2 (taking here not the most environmentally friendly ferry option, as the gas operated going from Turku using LNG would be with only 31kg/ CO2). (Here, I won’t include the calculations for turbine engine planes that were presented in the Vihreä Lanka-article mentioned in the previous paragraph.) 

Therefore, the ferry ride from Helsinki to Stockholm is 140 kg / CO2 two-way per person.

Ferries operate always on the purposes of freight also therefore it is sometimes questionable how should the amount of CO2 be allocated towards a passenger. But as there is also cargo on the planes and it seems that we can leave that as a side note as the optimal is always having a full capacity. Full planes and ferries for the fuel used.

The site gives a huge amount of CO2 to ferry ride, where the trip to Berlin made from Helsinki becomes more CO2 efficient by plane. 

The amounts (one-way) Helsinki- Berlin (here through Turku) are:

242,2 kg / CO2 for the train/ferry = amounts to 484,4 round-trip.

173,3 kg / CO2 for a car = amounts to 346,6 round-trip.

105,1* kg / CO2 for plane = amounts to 210,2 round-trip.

*Not taking in consideration all the warming effects of the flight (radiative impact). Also, I don’t know how it calculates the route to Berlin from Helsinki by proclaiming it taking only 10hrs with a car. As one can go through the aforementioned Tornio-Haaparanda route but this will evidently take more time than that, as will going through Russia. And through Baltic states we still face the necessity of the ferry when travelling with a car.

But it is safe to say that ferry ride is the main contributor when travelling land (/sea) based from Helsinki. This shows when the travel is calculated from Stockholm to Berlin and the parameters look like this:

Train: 42,9 kg / CO2, amounts to a round-trip of= 85,8 kg / CO2

Car:106,0 kg / CO2, amounts to a round-trip of= 212 kg / CO2

Plane:139,8* kg / CO2, amounts to a round-trip of=279.6 kg / CO2

In making the rough estimate based on these I would say that the round-trip ferry/train option from Helsinki to Berlin and back lies somewhere between 500 kg/ CO2 and 300 kg/ CO2. (It’s good to note that through Turku with LNG powered ferry the estimate of the same two-way trip is as low as 147 kg/ CO2.)

At this moment, when we can see that with choosing certain options, flying and land-based travel (ferry/train) may result in quite similar CO2 emission results. One can estimate how much difference it makes that the energy transformation is done with all the possible modes of transportation, and that one is mindful of the options available (LNG or Diesel-powered ferry for instance). If one travels somewhere farther away than Berlin from Helsinki via land-based methods the benefits caused by train travel will be more pronounced. I selected Berlin as a symbolic route due to the fact that from there one can reach quite widely southern and western connections. But of course – when travelling from Helsinki and if going through Sweden and Denmark – Hamburg would be the first major hub of connectivity. As still waiting for the Rail Baltica to be operational – the hope of getting better land-based connections from through Baltic states Helsinki improves., as many carbon calculator sites, is limited and one cannot count for the long-distance trips. (Like the trip from Helsinki to Tokyo for instance.) Also, it’s good to note that using calculators from websites that offer compensation services for CO2 emissions might have an initiative to count a higher emission load. 

As I have used this website: (that aims that you buy trees) to estimate the same Helsinki-Berlin round trip it gave me these numbers:

By Car: (2 persons or more)

763 kg / CO2 (petrol)

By Train:

6 kg / CO2

By plane calculation that was mentioned before: 444 kg / CO2 per person two-way.

These calculations are difficult, and it is quite important that even though aiming to benefit the cause, that numbers wouldn’t just be coming up without any relevancy in the online calculators. Like here in the site the very odd result of 6 kg / CO2 for train travel. I see that – due to the very acknowledged factor of flight emissions – many carbon calculation models utilize similar data that approximates the same amounts of emissions per flight (and the differences of adding or not the radiative impact effect the numbers) but the same does not go with estimating the emissions of using cars as land-based methods – where in addition of what kind of fuel is used, the amount of people that travel together, as well as the route (and speed) effects a lot the calculation.


It is important to note that even though trains are the preferred option (especially electricity powered) the train grid doesn’t take you everywhere. I will note that using buses is a good land-based option as well. 

But sometimes a land-based method has to mean a car, especially when you want to travel to a very remote location or you want to bring something with you (like equipment or materials). In the case that your car is full electric (or hybrid, or fuelled by E85), and you have more than one passenger on board, you are most likely to get more effectiveness per person for the emissions that the trip will cause.

As an example, I have the drive to Svolvær in the Lofoten islands in Norway and back to Helsinki. Since google maps is not – yet – showing calculations of the emissions (which would be convenient) I have to find data from other sites. (Google Maps will start from US and then globally to direct drivers on the eco-friendly options,, accessed 7.4.2021) 

2nd example:

By Plane: (2 persons) From Helsinki to Svolvær (Lofoten, Norway) and to Helsinki

832 kg / CO2


860 kg / CO2

By Car: (2 or more persons).

From Helsinki to Svolvær (Lofoten, Norway) and to Helsinki

687 kg / CO2 (petrol car)

35 kg / (E85 / ethanol)

The compensation site gives the route an estimate per kilometres and car and fuel type an estimate of 524 kg / CO2 per direction.

Amounting to 1048 kg / CO2 two-way.

This site gives the route calculations also with ethanol, amounting to the round-trip would be 600 kg / CO2

And with electric 276 kg / CO2 (also round-trip).

As I have done this trip in 2019 driving to Lofoten Island from Helsinki then with a petrol car (Volvo S40, 2004) I calculated the CO2 with these parameters in the calculator that one can choose the type of car (the one I used before in the overall lifestyle measurement.)

This calculation providing the amount of 360 kg / CO2 per direction, totalling to 720 kg / CO2 for the trip with the petrol car that we had. 

The amount that the calculator gives to our current car – plug-in hybrid Mitsubishi (outlander PHEV, 2014) – for a huge 10 000 km drive is 590 kg / CO2. The trip to Lofoten islands with our current hybrid car would be, based on the calculator only 180 kg/CO2 trip. (I expect it overestimates the use of electricity as a possibility for this hybrid model as the electricity can be used only in the range of about 20-40km. But with a full electric car I would see that as a relevant number.)

As to reach Lofoten Islands there are no trains available – you can take some parts of the trip by train (depending where you are travelling from) – but buses and Hurtigruten ferry line do operate and one can reach the islands with them. The effects they might have I have not calculated here with my emphasis on cars as a travel method. Also, it is worthwhile to mention that Norway is also focusing on electric airplanes, which could provide aid in shorter distances and to places that are hard to reach. (, accessed 7.4.2021)

The land-based option of using a car is highly dependent on the driving force used and the amount of people travelling together.

But I see that as an estimate the situation is quite clear, trains are always a more sustainable option in terms of CO2 when travelling in Europe especially. The variables are affected greatly and the best scenario is when one is able to travel longer distances with a train. If a major part of the trip is travelled by train it will affect the total carbon load a lot. 

As we travelled land-based by train to Venice from Helsinki in 2019, I am now using the calculations to estimate how our decision for a land-based route affected the carbon footprint of the trip.

3rd example:

The ferry trip Helsinki-Stockholm being 70 kg / CO2 one way per person, totalling to 280 kg / CO2 two-way two person.

The train from Stockholm to Venice (through in our case Copenhagen, Hamburg, Munich and coming back Vienna, Berlin, Hamburg, Copenhagen) is estimated at 80,2 kg / CO2 per person per direction. Amounting roughly to 320, 8 kg / CO2 totally for us two.

Therefore, let’s estimate for the sake of estimating that thus our 2 person return trip to Venice from Helsinki was 600,8 kg / CO2 total.

And now let’s compare this to the flight option, gives the amount of 170,3 kg / CO2 per person one-way, this being total for two-person two-way trip = 681 kg / CO2 (no radiative impact included). gives one person one way the average amount of 505 kg / CO2. Which would be a two-person return trip total = 2020 kg / CO2. Another compensation website gives the trip Helsinki-Venice (one way one person) an amount of 343 kg / CO2. Total 2 persons return trip being = 1372 kg / CO2. 

I will use the last number = 1372 kg / CO2 as a fair estimate as it is conveniently between the other numbers, and it also takes in consideration the radiative impact. And it gives a very concrete and symbolic comparison of land-based emission load being at least half the amount of emissions compared to a direct flight. 

We will not discuss the costs of the trip, nor the time as a factor in this occasion. Because, I will add, as we sleep and eat something hopefully every day, therefore for instance basing one’s diet on vegetables is the carbon clever option whether on a trip or not. 

Now, as an interlude, after having tried to find my way amongst all these calculators it is good to point that:

*It's only an estimate*

I’ll quote here Rail Europe blog about the train carbon footprint calculations:

“Calculating carbon footprints can be tricky, and our estimates should be taken with a pinch of salt. For more accurate calculations we *should* consider:

- The model of train or plane, including fuel consumption

- For electric trains, the method of electricity generation (we currently use the French grid electricity factor, since we sell the most journeys in France)

- The exact distance travelled by train, including its bends and curves

- The exact plane route, plus time spent taxiing before take off and after landing

- Occupancy: the fuller the vehicle, the more people to share the CO2

- Class of travel: First Class uses more space and therefore more CO2

- If the journey includes other forms of transport: ferries, buses, transfer by Metro/taxi etc.”

(, accessed 7.4.2021).


But as we have seen, the different online calculators give widely different estimates. Differences in carbon calculators have been explored for instance in 2007 in a study ‘A comparison of carbon calculators’ related to the calculators available then in the US. (Also after that with other studies, for instance ‘The state of carbon footprint calculators: An evaluation of calculator design and user interaction features’ by Mulrow, Machaj, Deanes and Derrible published in ‘Sustainable Production and Consumption’, volume 18, April 2019.) These examples come from the US because of biases of my online search engine and the language I use. I apologize for not being a very thorough overview of the studies available on this subject matter. The authors of the article ‘A comparison of carbon calculators’ from 2007 conclude that the variations of carbon footprint measurements vary a lot, due to the different conversion factors or calculating methodologies, and they emphasize the need for greater transparency of how the calculations operate. Noting that these calculators can be a way to increase public awareness of the CO2 emissions. (J. Paul Padgett, Anne C. Steinemann, James H. Clarke, Michael P. Vandenbergh,, link accessed 7.4.2021). 

Evidently clarity on how the calculations are conducted will be important, but it is also difficult for a person not equipped with detailed scientific knowledge to assess if the results are correct and based on what would the methodologies be changed. A standardization of some trusted and authorized calculations catered for regular people is therefore needed.

In the article ‘Beyond Carbon Footprint Calculators. New Approaches for Linking Consumer Behaviour and Climate Action’, published in August 2020 in the ‘Sustainability’ journal, authors Mario Burgui-Burgui and Emilio Chuvieco distill in the abstract their aim of developing a new form of CF accountability that is not just measuring the Carbon Footprint (CF) “but also on making users reflect about and eventually change their lifestyles to reduce their personal emissions.” This means not measuring only the emissions with a calculator but also providing different consumption scenarios.

The authors state that: “[s]everal authors have shown that a large percentage of GHG [greenhouse gas] emissions (60–70%) are related to personal consumption which indicates the relevance of individual decisions on climate change mitigation, and the importance of linking Climate Action and Responsible Consumption, both included in the Sustainable Development Goals (Goals 13 and 12, respectively). [The UN stated goals].

They also mention the following Birnik [Birnik, A. An evidence-based assessment of online carbon calculators. Int. J. Greenh. Gas Control, 2013.]: “carbon calculators constitute a potentially powerful bridge to connect individual action and lifestyle choices with the increasingly urgent need to prevent dangerous climate change”.

They also have identified the situation that is present: “that there are no standards regarding how CFC [Carbon Footprint Calculators] should be programmed, nor the methods or calculations they should incorporate to get consistent results. This implies that very different values can be estimated from similar user behaviors, or even with the same inputs, which reduces the credibility of CFC to promote actual changes.”

“In other words, they inform about the impact of the actual behavior (that is after the consumption was made), but they fail to inform about different alternatives before the consumer decision is taken. For instance, most CFCs include information on actual emissions derived from using a certain car, but they do not inform about which cars have lower CO2 emissions when somebody is willing to buy a new one. CF of alternative choices are also a practical way to find out which ones are more important to reduce personal emissions and to focus on those decisions that really matter.”

The team designed a Carbon Footprint Observatory named CO2web ( that is freely available online. In the article, they go over the process of making the observatory with also the perhaps obvious and persistent difficulties: “The main difficulties and limitations found to generate the CO2web observatory were related to the accessibility and characteristics of the data”. The variables of how to account the differences in for instance national situations (the authors mark for instance energy mix available) is something that makes a comprehensive tool for assessing the climate (or environmental) impact quite difficult to make.

But the authors conclude: “Carbon footprint calculators are valuable tools for estimating GHG emissions, familiarizing the public with issues related to climate change and the concept of carbon footprint.  They can also increase public awareness about how their lifestyles impact global warming and suggest behavioral changes. However, many of these tools have shortcomings related, among other things, to transparency, rigor, comprehensiveness or recommendations to reduce the footprint.” (Article found here:, accessed 7.4.2021). 

This Carbon Footprint Observatory named The CO2web is currently only in Spanish therefore I didn’t try it out due to my lack of language skills, but the authors stated that it will be available in other languages. My overall wish is that there could be usable tools that aid in making sustainable decisions. Even though understanding very well that making a total estimate of the climate impact is almost impossible due to the many factors that affect. (Like when buying a new electric car, building an eco-friendly house, or laying new rail tracks, the emissions of the production have to be taken into account as well.)

It is not in itself beneficial if one gets confused by trying to estimate one’s own carbon footprint. But I do think that these calculations can provide some sort of understanding of the scale. Here in this text especially when thinking of travel options and methods, but also of course with the calculators we can aim to provide clarity of how much – with choosing different options personally – we can affect our personal CO2 emission load. But it is good not to forget the need for policies that forefronts green agenda and climate acts on governmental and global level. The issue of tackling climate change impact is urgent and needs activity on all levels. I therefore am proposing that we act with our personal magnitude as well, even though we have to demand more climate acts and environmental impact consideration from legislators and industry – reducing CO2 emissions and avoiding environmentally damaging impacts has to be in overall taken in consideration as a part of ANY activity.