Comments on: Big Ships, Not So Bad…

By: CR McClain

CR McClain — Thu, 11 Oct 2007 13:08:58 +0000

Tom thats 0.5 mW (milliwats) versus 1W.

By: bigTom

bigTom — Thu, 11 Oct 2007 02:18:36 +0000

That sounds like a pretty significant effect to me .5W/M**2, versus a bit more than 1W/M**2 from CO2. If these numbers are right this effect could be masking about a third of the CO2 forcing!

Jeb: The jet contrails occurring at high altitudes tend to have a warming effect (they shield more long wave radiation going to space than they reflect sunlight). Low clouds don’t shield much long-wave, as their temperature is not much different from the surface temperature. So from a cooling perspective low clouds good, high clouds bad.

I have heard geo-engineering proposals to exploit this effect to mitigate climate warming. Of course we hopefully don’t need to burn fossil fuels to create condensation nuclei. And the geographic distribution of the forcing is un-even. But perhaps it can be used to mitigate the zeroth order effect of global temperature increase.

By: Jeb, FCD

Jeb, FCD — Thu, 11 Oct 2007 01:54:30 +0000

Wasn’t a similar point made after 9/11 with jet exhaust influencing weather or storm formation patterns?

By: CR McClain

CR McClain — Thu, 11 Oct 2007 01:37:27 +0000

Dave,
Great point. The fossil fuels these ships guzzle and the emissions are still in play and may represent a considerable source to ecological damage. Have edited the post to say this.

By: FishGuyDave

FishGuyDave — Thu, 11 Oct 2007 00:38:48 +0000

Okay, let’s start from the perspective that a) I haven’t looked at global albedo effects vs. global warming and b) I don’t have access to the full article. In practice, as an applied researcher, I’d have still (somewhere in the Discussion section, probably) have talked about the relationship between albedo and overall CO2, etc. effects of increased hydrocarbon burning/emissions — to do otherwise would be frankly shirking the application of such work.

So, albedo might be good, but CO2 and CO emissions off those ships probably offset any of those positives. All positive anthropogenic effects of buying cheap wooden frogs and tequila/rum aside, big ships still equal bad things ecologically. My challenge to the authors of the study is to prove otherwise.

Just my two-cents’ worth…