9 thoughts on “Ships produce more CO2 than airplanes?”

  1. I am tempted to say “yeah, so?” to this. We have in major usage two kinds of heat engine, piston and turbine, and this has been the situation for many decades. Until we find an alternative, or get into using hydrogen in a big way (to run the present heat engines), whether shipping or flying release more carbon just boils down to which one use more energy at that point in time.

  2. I suppose we should start shipping everything by air and stop using ships altogether. (This result doesn’t seem surprising).

  3. Not only airplanes produce less CO2 than ships, they also keep us cooler. One pilot told me that in a few days after 9/11 the atmosphere temperature over the US increased by a couple of degrees. That was attributed to the absence of sun blocking con trails from thousands of airplanes.

  5. Quite possibly, though isn’t the figure we want to look at the emissions per tonne of cargo (or, in rarer cases per passenger) per great circle kilometer?

    I suggest great circle km because a ship taking cargo from New York to L.A. would go via Panama and travel a lot longer than air cargo.

    Friends of mine have interesting answers: One is http://www.kiteship.com/

    Another has plans to build a fleet of fully-automated small sailboats that you can just give slightly offshore coordinates to and they will sail there using wind and solar, however long it takes them. Really cool though he has not solved the question of piracy. You could program the ships to sink themselves if they detect attack but I am not sure it would work.

  7. It’s just the larger volume that travels by ship. Per ton mile, an airplane generates about 100x more CO2. But nobody ships oil, coal, steel, wheat, etc. in large volume by airplane. Those go by ship or rail. Ships carry far more tonnage than airplanes.

    The biggest kerfuffle around ships is their pollution impact. Many ships can just ignore pollution regulations and do. CO2 generation is one of their better points. Fuel consumption is an important part of the price for shipping. Improvements in fuel consumption are a regular interest to shippers, because it remains a very competitive industry. There is a steady effort to make improvements, for much the same reason that there is a steady effort to improve airplanes. It’s other pollution areas where they lack a financial motivation to improve.

  8. I work in the Port of Los Angeles. The amount of cargo that airplanes carry compared to ships doesn’t amount to a flea on a dog’s ass. International shippers can dramatically lower their emissions by simply banning the use of low-grade “bunker fuel” in their vessels. But they won’t until they’re forced to because it’s a fraction of the cost of the cleaner burning stuff.

    Here in LA/LB, which is the largest port complex in the USA, so called “green” terminals are being implemented (slowly) which will require ships to “plug-in” and operate under electric power while docked. That alone is a significant improvement.

  9. I work for one of the leading ship classification societies, and I can tell you that shipping carries 90% of the goods that are moved from one place to the other.

    We should be careful when talking about “emissions”. This needs to be quilified by which type of emissions. For example, if ships were to switch from bunker fuel to distilled fuels, they would virtually eliminate the emission of SO2, but their CO2 emission would actually increase slightly (Many have been saying that CO2 would decrease, but this is incorrect). If a ship were to slow down, it would reduce CO2 tremendously. However, ships that are designed for this speed would increase their output of NOx if they are slowed down. Ship engines must be designed and tuned for the lower speeds.

    Other options for ships to reduce emissions of all types would be to improve the coating on the hull of the ship. Using the right coating reduces barnacles and other ocean life that builds up on the ship’s hull and slow it down. Better coatings can make a huge difference.

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