Post #28 Sustainable Ocean Cruising? Small Bytes of Info.

I like the ocean a lot & have been a passenger on about 35 ocean cruises. When I refer to “bluer” ocean cruising in this posting category, I mean cleaner/better for the ocean / our health, & kinder to marine life. More sustainable. I invite you to learn along with me.

We might digest this big topic a few bytes (or small bites) at a time. Even a bit more knowledge might empower us to make more sustainable cruising choices (e.g. choice of ship). It’s also some info. to share onboard (in the spa, while reclined in a deck chair, conversing with the officers … options).

Noted before, that I had not yet seen a carbon emissions stat. comparing ocean cruising to other types of travel. Now I have started seeing these (& still looking for a best, clear to understand article). I have now read that ocean cruising might generate approx. 2X more carbon dioxide per person per hour, than flying somewhere in a jet. Haven’t seen calculation details, & I already believe this statistic would vary e.g. depending on which ship one cruises on.

& I absorbed a recent environmental website article stating “Vacationers Generate 8 Times More Carbon on a Cruise Ship than on Land”. I am believing that 8X might be the worst case scenario. Details were missing (e.g. old ship? or newer ship?). One of the bottom lines: even if “a high carbon itinerary on land, the difference … startling”.  So cruise afficionados: let’s do even better. With our choices of ship & itinerary. Via feedback to the cruise lines. By knowing a little more. Let’s learn a bit about ship emissions & ship scrubbers.

Ship Emissions. Ocean cruising can perhaps be regarded as part of the commercial ships that transport roughly 90% of the world’s goods, apparently generating approx. 3% [of all?] CO2 emissions. There are further emissions from operating commercial ships. (If a fossil fuel is used, then) depending on factors like type of fossil fuel, engine combustion conditions & engine load “some or all of the following emission types will exist:

Free Nitrogen, N2; Free Oxygen, O2; Water Vapour – H2O; & Carbon Dioxide – CO2

Also possible: Oxides of Nitrogen – NOX; Oxides of Sulphur – SOX; Hydrocarbons – HC;
Carbon Monoxide  – CO;

Particulate Matter – PM; & Traces of other gasses such as argon & micro pollutants in trace quantities
such as polycyclic aromatic hydrocarbons (PAHs) & dioxins.”

Yikes. Though let’s notice that a few of the above sound fairly simple and/or benign (water vapour, oxygen…).

& Some of above are in relatively small, or micro, amounts. We can note that there are potentially a lot of negative emissions.

Ship Scrubbers. In a recent era, scrubbers were told to be one of the beneficial answers. Ships were being retrofitted/outfitted with scrubbers (instead of a more costly switch to cleaner fuels). Though now we can read opinions that “‘scrubbers clean the air – while contaminating the sea” & “cruise line scrubbers turn air pollution into water pollution”.Some background context/commentary about scrubbers, from Fall of 2019, advises:
“The International Maritime Organization adopted a sulfur [sulphur] cap to reduce the dangerous effects of HFO [Heavy Fuel Oil] … but permitted a loophole requested by the shipping industry” [basically the loophole: installing scrubbers]. Around half of cruise lines then decided to use/install scrubbers to comply with the newer sulfur cap rules.

One reads that using low-sulfur fuel would have been more expensive (than scrubbers).Some newer cruise ships now sailing do use cleaner fuels, & it looks like many mainstream new ship builds in the works anticipate using alternate fuels and/or power.

We have now learned (or already knew) that we could ask:

Q. How clean do the engines run on this particular ship? (Are harmful emissions minimized? If so, how?).

Q. Does this particular ship (still) use scrubbers? If so (& in light of the comments above), please tell me more.