Interesting Trawler vs Auto vs Airline CO2 emissions calcs

[socalrider]

With COVID lifting we're back in traveling mode this summer; I ran some quick calculations while watching tennis this am on CO2 emissions per "family mile" (to move all five of us) from our home base in San Diego; thought I'd share if anyone's curious.

Assumptions:
0.39 lbs CO2e / passenger mile by air
20 mpg for our Odyssey minivan
2.2 statute mpg for our CHB41 trawler

Outputs:
A family trip to Europe (6000mi) by air is about equivalent to taking the boat all the way to the Pacific NW

Our typical summer 6 week cruise up to Santa Barbara and around the channel islands is about equivalent to a cross-country road trip in the Odyssey or air travel to my brother-in-law in St Paul, MN.

A trip to Catalina and back is equivalent to air travel to San Francisco

Conclusions:
In the real world for most people, air travel CO2 emissions are astonishingly high relative to trawler emissions given the frequency and length of air travel vs boat travel. It's different if you're not multiplying the air miles by a family of five of course. But if you're on your own or as a couple, it's a lot easier travel by air so you're likely to do it more.

 

[FWT]

This is an invitation to political disagreement. Global warming topics are divisive.

 

[twistedtree]

I think/hope we can discuss the calculations and assumptions without getting into politics....


It's and interesting look at things. Not the only view of course, but it's always interesting and informative to compare things. Humans are really prone to get excited about one thing that's in front of them rather than making such comparisons which can help guide priorities for behavior, etc.


This looks at family miles traveled. One key thing it doesn't take into account that is critical with general travel is the time it takes to travel those miles, and that overwhelmingly drives mode of transportation selection, I think.


Since it's a vacation, another view would be CO2 per day of fun. With that perspective, your trawler numbers are probably about right. But the Euro Vacation would have to roll in all the CO2 impact of you activities once there. Presumably you would be in cars, trains, and buses for the 6 weeks in Europe. Same with a trip to SF or anywhere else.


Regardless, thanks for posting.

 

[Fletcher500]

Interesting to see the numbers side by side for each mode of transport.

 

[socalrider]

Since it's a vacation, another view would be CO2 per day of fun. With that perspective, your trawler numbers are probably about right. But the Euro Vacation would have to roll in all the CO2 impact of you activities once there. Presumably you would be in cars, trains, and buses for the 6 weeks in Europe. Same with a trip to SF or anywhere else.

For sure you're correct.

That would make my trawler impact even lower relatively speaking - we have an e-spirit electric outboard, make & heat our own water from solar, so zero grid electricity, no gasoline for car travel & just a bit of propane for cooking. From my calcs we'd be emitting about 70% of the CO2 from our cruise by just continuing our normal activities through the summer (driving and home electricity).

All this to reinforce that this is a pretty low-impact way to spend the summer, particularly when compared to flying places far away.

 

[Sababa]

This article estimates that all recreational boats in the US together emitted 13.6 mmt CO2 in 2020. This amounts to three tenths of one percent of the 5,981 mmt emitted from all sources and eight tenths of one percent of all transportation emissions (27% of total per same source) in the US for that year. As a small and relatively fuel efficient segment of the overall recreational boating mix with little in the way of reasonable alternative sources of power, trawlers seem like the last thing to worry about when it comes to fighting climate change.