There Is No Free Trade: Cargo Shippers Emit Twice The C02 Of Airlines, Yet Go Completely Unregulated

Reducing the emissions of ocean shipping and cruise ships is a laudable and overdue goal. It would be good for aircraft to also become more efficient and less polluting.

The statistics quoted seem to be a little misleading, however.

There should be an 'emissions/ton of goods shipped' calculation used. Airplanes carry a growing, but still relatively small percentage of total goods shipped worldwide. Aircraft emissions are almost certainly 10-100 times more polluting on a pound for pound basis.

Water borne shipping is widely acknowledged as the most fuel efficient method of moving goods over long distances. Increasing shipping's total share of goods moved has significant environmental benefits. As more goods are shipped by water, it is quite likely that total emissions of that sector will rise, while emissions per ton will decline substantially.

Not to clarify the issue adds confusion to the discussion and is a disservice to the discussion and your readership.

==== author's response follows ====
You are correct that the picture is complex. In addition to what you mentioned, cargo ships are pulled into dry dock for maintenance in 5 - 10 year intervals. By their third year of operation, fuel efficiency typically has degraded quite dramatically because of barnacle infestations (slowing the rate of hull fouling for many years at a time is why biocidal organotins were popular in hull paints).

Every day in dry dock ,much is profit lost; hence the importance of ship design trade offs between keeping operating cost down, efficiency up, and revenue coming in. Traditional emphasis on marine propulsion design is likely to have been on running steady more than on fuel efficiency.

Ideally, the playing field for upgraded efficiency standards could be made level by global treaty between developed nations. The problem lies in the determining which nation or company "owns" the problem. The ships may be designed far from where they are built , maintained, and registered and ownership may change between nations while flagging remains the same. Very confusing.

The article sheds light on an overlooked issue that we will probably be hearing more about soon. Design standards and a reasonable schedule for phasing out the inefficient designs are top of the agenda.

Everything I write is based on the assumption that there is a 25% or greater chance that we must act dramatically within this decade to avoid a global climate catastrophe. There is no way fleet average cargo efficiency is going to be increased dramatically in this time frame. Therefore, I stand by the buy local recommendation.

So... which one is more polluting again then?And what does emitting twice the CO2 of airlines mean if, as jon points out, there's a difference in CO2 emitted per pound?

Whenever we're faced with statistics like these, wouldn't it be better if somewhere in the article, someone mentioned what kind of measurement unit they were using?

I see two ways of solving this.

A) Global agreement that all freight ships must meet efficiency standards by the 20xx. This would be very difficult to do, as if one country didn't sign the treaty, then the vast majority of ships would be registered in that country, boosting revenue for a presumably poor nation, while still polluting.

B) An agreement between major industrial nations (EU nations, Japan, USA, Canada, etc.) to ban excessively polluting ships from docking and unloading. This would loose income from those nations, so possibly having an additional fee for highly polluting ships.

I agree that the figures are misleading. Ocean and rail transport is much more efficient than air. This is one case where the free market does work. If somehow it were cheaper to fly your goods somewhere, in a role reversal (imposable, but just for example), then the air shipping industry would create probably in the range of 10-100 times as much CO2, and in a worse place.

"The solution? When you have a choice, buy local; buy home-sourced."

That doesn't always follow. In some places, "local" production of goods requires much more energy and generates more emissions than producing tham elsewhere and shipping them. You need to take into account the environmental impact of the whole lifecycle of the profit, not just "food miles".

Tom - Be honest, that's not a solution - that's what we who care do when we can to make ourselves feel better about a problem that is far beyond our control. As we all know we will not shop our way out of this mess and it is the very industries we criticize that offer the ONLY possible solutions to GW. Job number 1 for us is to push hard those in a position to make a real difference. EVERYTHING else is vanity and that's ok.

I have read the article “CO2 output from shipping twice as much as airlines” published in The Guardian yesterday, and your comments on that article – I have made some studies on the energy consumption in Danish shipping and here are the extracts.

Energy consumption in Danish international shipping industry and climate change
Denmark often wants to be the green pet in the class; but ,some facts may spoil this picture.

The energy consumption in the Danish shipping industry are disproportionate huge compared with the total energy consumption in Denmark, and also in relation to the Danish shipping industries contribution to the Danish economy. Furthermore, there is at corresponding huge negative impact on the environment and the climate.

The fleet flying the Danish flag and the fleet owned or operated by Danish shipping companies consumes twice the total Danish energy consumption. As the Kyoto protocol do not cover marine and aviation bunker, this total amount of marine bunker, approximately 30 mill tons of heavy fuel pr. year, are not registered or notified in the national and international statistics.

It is crucial to inform the public about the emission from the shipping industry, and I am glad too see this article. Also Denmark downplays the problem.

(I am a former government official and have participated in meetings held by the IMO’s maritime environment protection committee)

The headline of the Guardian column is misleading. It should read: "CO2 output from entire shipping industry worldwide greater than total emissions from aircraft." This would be entirely true. Because shipping is more efficient, most goods are sent by ship. Therefore the total emissions from shipping are quite huge. Air Cargo is expensive and inefficient, therefore its relative emissions are small. Consumers demand global goods, and as long as they do, I will hope that they are transported by ship, not air cargo.