In Shallow Water Ships Trigger Seafloor Methane Emissions, Study Finds (msn.com) 24
An anonymous reader shared this report from the Washington Post:
Ships trigger seafloor methane emissions while moving through shallow water, researchers report in Communications Earth & Environment. The scientists say the unexpected discovery has nothing to do with the type of fuel used by the ship. Instead, "ship-induced pressure changes and turbulent mixing" trigger the release of the gas from the seafloor. Bubbles and gas diffusion push the methane into the atmosphere, where it acts as a greenhouse gas...
Container and cruise ships triggered the largest and most frequent methane emissions, but the study suggests that ships of all kinds, regardless of their type of engine or size, trigger methane emissions. Researchers said they observed emissions that were 20 times higher in the shipping lane than in undisturbed nearby areas. Given the number of ports in similarly shallow areas worldwide, it's important to learn more about emissions in shipping lanes and to better estimate their "hitherto unknown impact," study co-author Johan Mellqvist, a professor of optical remote sensing at Chalmers University of Technology in Sweden, said in a news release.
Container and cruise ships triggered the largest and most frequent methane emissions, but the study suggests that ships of all kinds, regardless of their type of engine or size, trigger methane emissions. Researchers said they observed emissions that were 20 times higher in the shipping lane than in undisturbed nearby areas. Given the number of ports in similarly shallow areas worldwide, it's important to learn more about emissions in shipping lanes and to better estimate their "hitherto unknown impact," study co-author Johan Mellqvist, a professor of optical remote sensing at Chalmers University of Technology in Sweden, said in a news release.
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...with precise empirical observation that whenever I go wading in the surf after eating Taco Bell, there are bubbly methane emissions of a marine type.
Well, of a beachgoer type. A mess hall omelette fueled Marine will have emissions of an entirely different type. :-)
Easy fix ... (Score:3)
Re: (Score:1)
the green thing to do is build products on the continent they will be sold on.
If the raw materials are all on one continent, the end users are on another, and the finished product is less massive than the raw materials, it's going to require less shipping to build it where the raw materials are then ship it to the customer.
Also, what about things like coffee, that simply don't grow everywhere they are consumed?
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the green thing to do is build products on the continent they will be sold on.
If the raw materials are all on one continent, the end users are on another, and the finished product is less massive than the raw materials, it's going to require less shipping to build it where the raw materials are then ship it to the customer.
Sure, assuming the pollution of resource acquisition and the pollution of manufacturing is also figured in. Otherwise a locale might externalize the pollution to falsely appear greener than they actually are.
Also, what about things like coffee, that simply don't grow everywhere they are consumed?
No one said manufacture locally is always possible. Just that a goal of being greener may justify different practices than a goal of having cheaper goods. "Cheaper" has a cost at times; pollution, labor abuse, predatory behavior, etc.
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If you build local you won't have to ship quite so much stuff global. Giving you more room for raw materials and coffee beans.
Climate change will probably kill off the coffee industry, perhaps at the end of the century. You might have to learn to love roast chicory and dandelion root.
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So containerships are a problem, so the green thing to do is build products on the continent they will be sold on.
To counter your top-down slightly moralistic solution, a fairly standard economic analysis is that this effect is an externally borne cost (a negative externality), and it should be taxed equal to the amount of harm done, and the tax should be distributed to the ones that are harmed (in proportion to the harm). This is a logistical nightmare, requiring agreement from multiple governments about what the harm is and how the proceeds should be distributed. But it's a tidy theory because shipping would be less
Re:Easy fix ... [Onshore factories] (Score:2)
David Ricardo's grave is now releasing methane.
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with the ship passage (presumably creating pressure waves that disturb the muck).
Would natural (tidal, volcanic, storm-caused) disturbances release
less methane, or more, or the same amount, in the absence of shipping?
There's no clear benefit to that fix.
We keep finding new sources of emissions (Score:2)
It's no wonder the predictions of calamity and the real world weather keep getting worse.
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Indeed. To sustain the desired level of hysteria, the claims of gloom and doom have to constantly get more dire. Otherwise, people get used to them, and stop sending money to the doom criers.
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I'm trying to think who I sent money to.
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I'm trying to think
I have doubts, but if you are trying, you're failing.
Problem as old as ships? (Score:1)
If I read this right, ancient seafaring peoples had the same problem, just on a much smaller scale.
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I would expect it is primarily happening through vibration rather than turbulence, which would be tied to engine use more than oars or sails.
Could be useful (Score:2)
Buildup of methyl clathrates beneath the ocean floor have been implicated in mass-extinction events of the past. If overpressure from a ship's wake can partially release clathrates, we can control oceanic methane releases and prevent a mass release event in the future.
Which is worse?? (Score:1)
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Humans invent ever more ways to F up Earth.
What to do? (Score:2)