Carbon Emissions – Flying, Hitch-Hiking and Cargo Ships, the Facts

Now I’m firmly settled in Nicaragua and not moving from day to day, I finally want to write an article going into more detail about the environmental impacts of travelling the way I have. I’m hoping to see whether the time and effort has made a difference in terms of my carbon footprint – really the most important point of hitch-hiking and travelling by cargo ship. With this article I hope to make clear the justification for this travel, and also analyse whether there really are alternatives that could replace mass international flying. The article is a bit longer and more detailed than the others so far, but I’m hoping it will also be the most important one!

Carbon Footprints – Vehicles vs Passengers, and High Altitude Emissions

Every mode of travel has its carbon impact, whether flying, hitch-hiking or using ships – even walking requires our bodies to use more energy and release more carbon than just staying put! However, the carbon released by a mode of travel is not the same as the carbon we are responsible for – this depends on whether we contribute to the reason the mode of travel exists in the first place, or not.

Taking any mode of transport arranged for our use, we become part of the reason why the journey takes place – avoiding flying on passenger airplanes both directly reduces our carbon footprint and removes ourselves from the market that justifies the flight existing at all. Your share of the carbon footprint of a passenger airplane is therefore the total carbon it emits divided by the number of passengers on it. Conversely, travelling on a journey that would happen with or without passengers – taking a cargo ship across the ocean or hitching a lift in the free space in someone’s car – we are responsible only for the extra weight we add to the journey. Our proportion of the total carbon emitted is equal to our proportion of the total weight of the vehicle we are on, likely to be a much smaller value.

On top of these considerations is the fact that airplane emissions, especially for long distance journeys, have a much greater climate impact than other forms of emissions, because of how high in the atmosphere they are released. NO2 and water vapour also released by airplanes at this altitude are also greenhouse gases and mean the total warming effect is roughly 3 times the effect of the CO2 released (1).

Bearing this in mind, we can look numerically at the difference made on my journeys from London to Cairo, and from Europe to Latin America, by using the means of transport I have done, instead of flying on passenger jets. To write this article I have used numbers generated by online carbon calculators. No carbon calculator is perfect and I am thus restricted by whatever assumptions or limitations they may have, however I hope that the results they produce paint an accurate general picture of the impacts of different sorts of travel.

London to Egypt – the Numbers

First, the journey to Egypt. Taking a plane direct from London Heathrow to Cairo is a journey of about 3517 km, which according to the carbon calculator at chooseclimate.org would use 40,835 kgs fuel in total and release 429 kg of CO2 per passenger (if the plane is 80% occupied). With the other greenhouse gases, released at high altitude, this is the equivalent of 1287 kgs of CO2 released at ground-level.

The journey I made involved train travel for roughly 212 miles from London to Brussels, hitch-hiking a total of 2000 miles between Brussels and Sofia, and Istanbul and Iskenderun, coaches 496 miles between Sofia and Istanbul, and Port Said and Cairo, and the ferry roughly 431 miles from Iskenderun to Port Said – a total of 3139 miles, or 5022 kms.

Of these journeys, according to the well respected carbon calculator at resurgence.org (2), couch travel is by far the least polluting, releasing 0.048 kg per person of CO2 per mile, and the ferry by far the worst, releasing 0.192 kg CO2 per mile. Using resurgence’s calculators, with the public transport I used I had a carbon footprint of 127 kg.

Resurgence also gives the CO2 output per mile of different sorts of cars – as I used a variety of cars, I’m using an average value for petrol and diesel upper and lower medium cars, which from Resurgence is 0.315 kg per mile – 630 kg total on my journey. However, this figure doesn’t take into account the fact that I was a passenger in journeys that were already taking place, meaning most of the carbon released would have been released regardless of my journey. I weigh about 65kg, and a rough estimate for an average European car is 1500 kg (3), so in fact I was responsible for about 4.3% of the car emissions – 27.3kg in total.

So according to the calculators I’ve used, in total on the journey to Egypt I was responsible for 154.3 kg of CO2, 36% of the CO2 that would have been emitted by plane. When the increased impact of airplane emissions is taken into account, I’m pleased to be able to say that I succeeded in reducing my total warming effect to only 12% of what it would have been had I flown.

Across the Ocean

What about the cargo ship journey? By plane, a journey from London to Managua, Nicaragua, would normally involve changing a couple of times, such as in Boston and Miami, making for a total distance of 9272 kms. According to chooseclimate, the 3 flights would use a total of 109,592 kg of fuel. Per passenger this would release 1150 kg of CO2 per passenger, with a total warming effect equivalent to 3450 kg.

Unfortunately, finding quantities for the amount of carbon a cargo ship releases is next to impossible, so I can’t make a direct comparison here. However, I tried to get what info I could from the crew of the BF Ipanema while on it. The chief engineer told me that the fuel consumption of the ship is calculated as it goes along from various measuring instruments throughout the engine. On average, however, he was able to tell me that it uses about 50 tonnes of fuel per day. In 18 days travelling that is 900 tonnes of fuel – 8.2 times that required to fly!

The hardest thing to determine however, is just how much pollution is produced by this fuel. As well as the huge amounts of fuel ships use running their engines non-stop for days, carbon ships are notorious for using very poor quality fuel, in order to save money. The chief engineer told me that the ship uses 3 types of fuel – normal fuel oil when in port and low sulfur fuel when in European seas, in order to comply with regulations. However, on the open seas it uses the cheapest oil it can, with a sulfur content of 10%, and correspondingly bad effects on the environment. Although sulfur dioxide does not contribute to global warming, there is no doubt that the pollution from ship engines is particularly bad for the atmosphere as a whole. Just as airplane’s emissions are 3 times more damaging than those of normal ground-level travel, it may well be that emissions from ship fuel have a greater impact than normal land travel emissions. Regardless, with the large amount of fuel used it’s clear that the ship has at least an equivalent warming effect as the flights, if not greater.

However, as with hitch-hiking, as a passenger on the BF Ipanema I was tagging along on a journey that would have happened whether I and the other passengers were there or not. A cargo ship is of course a massive vehicle, and the extra fuel required to carry my 65 kg body is therefore negligible. According to marine tracker, the ship weighs 2,1018 tonnes, (the chief mate told me that on our journey, this included 15,000 tonnes of cargo). In total then, I was responsible for 0.0003 % of the power required to push the ship – a tiny 2.78 kgs of fuel. (I would also have used extra fuel for the amenities that I used – lights, heating and water, my computer, and the cooked food I ate – however, I would also have used these had I been sitting at home or travelling by other means. I’ve no measure of how much carbon I would have used in this way on the ship, or using electricity generated for my house or travelling by other means, but it’s unlikely that the difference would affect these calculations much).

But… Some Obvious Problems with Cargo Ships

Of course, the time spent getting across the ocean means that cargo ships can’t allow a trip in the time most people have for a holiday. According to the website of the company I got my ticket from, most passengers on these ships tend to be retired, which allows them the time for the trip.

In addition however, as I mentioned on my blog before I left the UK, cargo ship travel is also not a cheap option – in fact my one-way trip cost twice the price of a return plane ticket, at £1500. This is clearly a prohibitive price for a casual trip. Talking to the crew, it was evident that there was little cost to carrying passengers on the ship – a few dollars a day extra in food and very little staff time, so the high price seems to be an unnecessary barrier to allowing more people to travel on cargo ships, and I tried hard to discover why the companies charged it.

One of the 2 passengers, Friedel, had worked as a chief engineer on cargo ships for years before he retired, and now returned regularly to the sea as a passenger, once or twice a year, so he was an excellent source of information. He told me that normally, the trips he takes are much shorter – a week round trip in the North Sea for example – and that on those journeys the ships are normally full to capacity with passengers. Each day of the short trip is charged at the same rate as the journey across the ocean, so with this fixed rate the shipping companies are able to get a full complement of passengers for most of their journeys, even though the long distance ones are much less affordable. The BF Ipanema was only carrying 3 out of a possible 7 passengers, so why the companies don’t reduce their rates for longer trips, making this alternative to flying more accessible, I do not know!

Conclusion

But even if more people had the time and money for these journeys, could cargo ships ever really offer an alternative to mass international airtravel? As we’ve seen, cargo ships themselves are no less polluting than airplanes, in fact using about 8 times the fuel of an airplane for the same journey. They therefore only count as an environmentally friendly option as long as the passenger does not contribute significantly to the reason the ship travels.

Friedel also told me that cargo companies first started to take passengers when the internationa

l financial crisis of the 80s pushed them to look for other sources of funds. However, while the extra funds from passengers is of course valuable to the companies, at the moment it is certainly not their reason for operating. Nevertheless, if ships were used to replace and significantly reduce the amount of flights we take as tourists, the shipping itself would have to become a passenger industry, and the carbon they emit would no longer be for the sake of cargo, but a part of the footprint of the passengers themselves.

So what does this mean in the long run? The simple, unavoidable fact is that mass international travel powered by fossil fuels inevitably involves pumping out huge amounts of carbon. There is simply no way with our current technology to get the energy required for such long journeys without it being a significant part of our society’s carbon footprint. The conclusion then is that, if we are to take seriously our responsibility for climate change in the West, we will have to reduce the flights we make, and search for alternative technologies to replace them. Needless to say, as the impacts of climate change are felt more and more consciously by us, these changes will start to seem more urgent. Unfortunately, by then it will be much too late to do anything about it, or prevent catastrophes in tropical countries such as Nicaragua, where the effects of climate change are already evident.

What alternatives are there? The most obvious is not to fly – a huge amount of business travel could be avoided by communicating over the internet for example. But shorter flights are also much better than long ones, as they emit their pollution at lower altitudes. As far as holidays are concerned, this means more holidays in the UK, and more in easier reach by train in Europe. With the Eurostar, all of Europe, including the sunny Mediterranean, is available to us without flying. Although you won’t be able to get there and back in a weekend, by land you get to see all the places you pass through on the way. And of course, if you were feeling really adventurous and wanted to meet some people on the way, you could always try hitch-hiking too, and have almost no carbon footprint at all!

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References

1. My information regarding flights’ emissions, their quantities and additional impacts, is from chooseclimate.org
2. My information regarding carbon emitted from surface travel is from resurgence.org
3. 1500 kg for the weight of a car is a figure I found on a few websites, including this one, the specs for a BMW