I'd love a napkin math calculation at this.

▲ shagie 9 hours ago | parent | next [-]

https://climate.mit.edu/explainers/freight-transportation

> While nearly three-quarters of the world’s cargo is carried by ocean-going ships, road vehicles like trucks and vans make up the majority, 65%, of freight’s emissions. Most ships burn fossil fuels and emit carbon, but they carry large amounts of freight at the same time, making them the most efficient way to move cargo. Road freight, however, can emit more than 100 times as much CO2 as ships to carry the same amount of freight the same distance. Road transport is also a fast-growing sector—80% of the global increase in diesel consumption can be attributed to trucks. E-commerce and home delivery are two reasons for this growth.

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BobbyTables2 2 hours ago | parent [-]

Not disagreeing but it’s amazing a ship plowing water out of the way is so much more efficient.

Perhaps trains beat road transport efficiency to a similar degree.

	▲	butvacuum 42 minutes ago \| parent \| next [-]
		classic volume grows faster than surface area. also, fuel is a huge cost (maybe even the main cost), and drag has a >linear relationship with speed- so the ships will slow down based on fuel prices.
	▲	tdeck an hour ago \| parent \| prev [-]
		This is why European cities had so many canals back in the day.

▲ OrderlyTiamat 9 hours ago | parent | prev | next [-]

The distance the boat has to cover is 11800 kilometers, and the truck covers only 54 kilometers. Taking that average of 12 times more usage from the table of sibling comment means the ship is still 20x worse.

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BrenBarn 9 hours ago | parent | next [-]

But what if you apportion the fuel usage over the items transported? Presumably the ship carries far more items than the truck.

	▲	OrderlyTiamat 9 hours ago \| parent [-]
		This is already taken into account: Shagie's table is based on [1], which is per kilogram-kilometer [1] https://climate.mit.edu/explainers/freight-transportation

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7 hours ago | parent | prev [-]

[deleted]

▲ cinnamonteal 9 hours ago | parent | prev | next [-]

The distance from Shenzhen to Long Beach is some 300 times the distance from Long Beach to Pasadena, depending on where exactly in Pasadena and which route you take. The CO2 emissions factor for a truck is some 10-100x that of a container ship. The exact ratio depends on what kind of truck, and what scope of emissions are being included. The more one accounts for, the more it will favor the boat. But overall, the emissions from the oceanic leg of the trip are probably anywhere from 1-3x those of the truck.

▲ shagie 9 hours ago | parent | next [-]

From the data at the end of https://climate.mit.edu/explainers/freight-transportation

    +----------+------------------------+---------------+----------+----------+
    | Mode     | Freight (bn tonne-km)  | CO2 (Mt)      | CO2/Frgt | Vs. Sea  |
    +----------+------------------------+---------------+----------+----------+
    | Air      |     303                |   155         | 511      | 79       |
    | Rail     |  10,842                |   170         |  15      |  2       |
    | Road     |  26,807                | 2,230         |  83      | 12       |
    | Sea      | 101,486                |   657         |   6      |  1       |
    +----------+------------------------+---------------+----------+----------+

	▲	mjevans 3 hours ago \| parent [-]
		Bulk rates and flatter surfaces win. However at some point branching is required, and the bulk rates also add latency.

▲ conductr 7 hours ago | parent | prev [-]

You have to normalize for package volume. There’s one ship involved, how many delivery vehicles and other auto related logistics until that whole shipload has reached its final destination?

▲ hi-wintermute 9 hours ago | parent | prev [-]

I did some napkin math on this as I recently picked up a 3D Printer and wondered the environmental comparison to print-at-home vs pick something up at the store and I was surprised. Had some help from Claude but "last mile delivery" is absolutely where the majority of the kWh is burned in the supply chain.

Container ships use ~0.015 kWh per ton-km[1] and a car is ~1.35 kWh/km.

If you go to the store and end up getting >10 things it becomes "worth it" from an energy standpoint. Anything less printing at home seemed to be more economical... Not an expert though just saying it opened my eyes to how inefficient "last mile delivery" energy consumption is.

[1] https://www.withouthotair.com/c15/page_95.shtml (old reference)

	▲	shagie 8 hours ago \| parent [-]
		> Not an expert though just saying it opened my eyes to how inefficient "last mile delivery" energy consumption is. One of the oddities of home shopping and delivery is that it can be more efficient. https://www.npr.org/2024/09/10/nx-s1-5020321/food-delivery-m... > In 2022, researchers from the University of Michigan and Ford Motor Co. modeled a single 36-item grocery cart to compare greenhouse emissions from an e-commerce grocery delivery and a traditional trip to the store to get the same items. Gregory Keoleian and colleagues at the university's Center for Sustainable Systems found that using an electric vehicle to pick up groceries could cut emissions by as much as half, compared to a gas-powered vehicle. > They also found that home delivery could be an even better option. That's because with a delivery vehicle, orders are often clustered, with a driver dropping off not just your groceries, but also hitting neighbors during the same run. "Delivery is actually going to be more efficient in general than driving yourself in a gasoline SUV to the store to pick up your groceries," Keoleian says. The mentioned paper is https://css.umich.edu/publications/research-publications/car... --- https://www.epa.gov/greenvehicles/what-if-more-people-bought... > A recent USDA survey found that in 88% of U.S households, people hop in their car to buy groceries, driving an average of 4 miles to their preferred store. ... All these car trips result in carbon pollution: over 17 million metric tons of CO2 come from car tailpipes just from driving back and forth to the grocery store. --- https://csanr.wsu.edu/how-do-grocery-and-meal-kit-deliveries... > While it is common for the consumer to associate convenience in the food industry with increased greenhouse gas emissions, this is not always the case. Results from a 2013 University of Washington study indicate that grocery delivery has the potential to reduce carbon emissions anywhere from 20 to 75 percent (Ma 2013), while another study out of Finland found the potential for grocery delivery to reduce emissions by up to 87 percent (Siikavirta et al. 2002). --- https://www.nytimes.com/wirecutter/blog/shop-online-sustaina... > Buying goods online can be better for the environment than in-store shopping for one fundamental reason: With online shopping, a single truck or van can replace multiple car trips, by multiple households, to stores. It helps to think of it this way: In most of the United States, almost every purchase means putting a vehicle on the road—either your own or a delivery company’s. --- Some others: https://blog.sevensenders.com/en/ecommerce-carbon-footprint-... https://web.archive.org/web/20250302115526/https://sustainab... (this one is quite comprehensive also including the difference in packaging) And those articles come with their own citations to other articles.