I made the mistake of reading Sustainable Travel Is Hard on Substack by Kyle. I love cruising, but I immediately knew that this was the worst for carbon emissions.
How Bad Are Cruises for the Environment, Really?
Cruises promise dreamy sunsets, floating cities, and endless buffets. But under the surface, both figuratively and literally, they leave behind a slick environmental trail. Here's the truth, with no nautical nonsense.
Cruise Emissions vs. Other Travel Modes
| Transport Mode | CO₂ per Passenger/km | Key Pollutants | Efficiency | Notes |
|---|---|---|---|---|
| Short-Haul Flight | ~255g | CO₂, NOx, contrails | Low | High emissions, especially during takeoff and landing. |
| Cruise Ship | ~250-400g | CO₂, sulphur oxides, nitrogen oxides, black carbon | Very Low | Worse per km when accounting for amenities and hotel-like functions. |
| Car (solo) | ~192g | CO₂ | Low | Better in EVs or with more passengers. |
| Train (electric) | ~41g | Dependent on the energy source | High | Europe’s trains often run on renewables or nuclear. |
| Bus (long distance) | ~27g | CO₂ | High | One of the most efficient options. |
Bottom Line: On a per-passenger basis, cruise ships are often worse than airplanes, especially when accounting for energy use from pools, casinos, elevators, and onboard waste systems.
And if that isn't bad enough . . .
Beyond Emissions: Hidden Environmental Costs
| Impact Area | Cruises | Notes |
|---|---|---|
| Waste Disposal | 150,000+ gallons of sewage per week (large ship) | Dumped at sea legally in international waters (often treated, sometimes not). |
| Air Pollution | Burns heavy fuel oil (HFO) — dirtier than car diesel | A single cruise ship can emit as much NOx as millions of cars daily. |
| Port Damage | Coral reef degradation, sediment disruption | Anchors and propellers wreak havoc, especially in tropical waters. |
| Overtourism | Floods small cities (e.g. Venice, Dubrovnik) | Strains the infrastructure, prices locals out, and pushes gentrification. |
| Noise Pollution | Sonar and engine sounds disturb marine life | Interferes with whale communication and navigation. |
| Food Waste | Buffets lead to extraordinary waste levels | Much is incinerated or dumped. |
| Plastic Pollution | Disposable cups, straws, and packaging | Often ends up overboard or in overwhelmed waste systems. |
Why It's Worse Than I Thought
Cruising is a floating city with 24/7 demand for energy, water, sewage, and labour. Most ships use heavy fuel oil, the dirtiest of the fossil fuels permitted for use. In my research, I discovered that even idling in port, they often burn the equivalent of dozens of trucks per hour unless they're hooked up to shore power (which few ports offer).
I decided to take a look at the Flight CO2 Calculator. Even our upcoming flight to Cape Town was a disaster.
Here I had been writing about Sustainable Travel, and I was the worst culprit.
Klye was nice:
The first thing I will say about trying to travel sustainably is this: do what you can in ways you can manage. Don’t bother yourself with aiming for perfection because it doesn’t exist. Don’t try to travel sustainably in the ‘right’ or ‘best’ way. Do what works for you. I promise, it is better than doing nothing.
But what will work for me?
When we are at home, we almost always take public transit, and we also have electric bikes. (Uphill cycling is a little too much for us at our age.) We do live in Canada, but we purchase local produce whenever possible. We are very careful not to overheat our home in the winter and keep the air conditioning at a reasonable level.
Travelling seems to be more challenging, and we are leaving a massive carbon footprint in the actual travel part.
“Low-Wake” Actions That Outweigh Offsets
| Action | Impact Multiplier |
|---|---|
| Fly less, stay longer | 🟢 Bigger bang for carbon buck |
| Choose rail over air (under 1,000 km) | 🟢 90%+ fewer emissions |
| Avoid mega-ships and luxury cruises | 🟡 Lower daily emissions |
| Stay in energy-efficient lodgings | 🟢 Boutique over big box |
| Eat local, seasonal, low-waste | 🟢 Underrated emissions savings |
I tried downloading some apps for tracking purposes, but that made me even more depressed and feel like a failure.
I am toying with the idea of Tithing.
Every time I book a flight or cruise, I can transfer 10% of the ticket cost into a travel offset “piggy bank” fund.
By the end of the year, I'll have a guilt buffer and a donation habit. I know that won't cover all of our carbon footprint, but it's a start.
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