"Our greatest responsibility is to be good ancestors."

-Jonas Salk

Wednesday, May 5, 2010

Ocean Ecologist Jeremy Jackson

Via TED; I was privileged to see him in person a few years ago at U Chicago.

He has plenty more where this comes from, including lots of data.

See also British Fish Stocks Fell Precipitously in Last Century for instance.


Steve L said...

At one point he sort of says, What's really troubling is increased stratification. I think I can understand why we think this might happen, but how certain is it? We might get more wind, too, that could balance or over-compensate for the factors promoting increased stratification. Couldn't we? I thought I'd heard that it's happening in a few places right now.

Michael Tobis said...

S, an interesting question. It sounded right when Jackson said it, but I thought about it some more.

I'd have to put myself down as in the "very likely" column on increased stratification. It actually raises one of the most interesting open questions in physical oceanography: how is the deep mixing controlled?

See, mass balance means that the deep mixing has to balance the sinking of polar water. But we are probably entering a period of suppressed sinking of polar water due to injection of large amounts of fresh water. We don't know how the mixing will "know" to balance that, but somehow the signal has to get there! But the upshot is less deep mixing even if there is little warming outside the polar regions, which itself would suppress mixing.

So yeah. I think he is right.

Yes, there may be increased energy in winds due to stronger stormsthat would pull the other way (that's not obvious; even that might be balanced by slower baseline winds, but it's plausible) but I think that won't win the tug-of-war against the suppressed overturning at the large scale.

Any other opinions out there?

Big caveat: This is just my own estimate, not the result of any research I know about. Anyone have a good handle on research on this?

Steve Bloom said...

Everyone seems to think so, pretty much as you have it.

Michael Tobis said...

Steve, that's not a fair test until you google "decreased stratification" too, but the score indeed works out as 409 to 12 in favor of your search.

I was hoping for something a little deeper than that, but I guess that really does tell us something.

Steve Bloom said...

"deeper" tee-hee

Horatio Algeranon said...

Few people see the big picture the way Jackson does -- and even fewer fully comprehend what they see.

And "stratification" is a metaphor for death.

Michael Tobis said...

"One of the penalties of an ecological education, is that one lives alone in a world of wounds."

— Aldo Leopold

Steve L said...

For ["increased upwelling" climate] I get 1,320; for ["decreased upwelling" climate] I get 256. I'm hesitant to conclude anything from this, but the mechanism mt describes seems at a bigger scale than the one I was originally thinking of. Maybe the phenomena are not mutually exclusive.

Michael Tobis said...
This comment has been removed by the author.
Jim said...

Here's a longer presentation (44 minutes): Brave New Ocean

"The future is bright for dinoflagellates."

Steve Bloom said...

S, you need to do it in Google Scholar (the scientific literature)as an exact phrase search and then actually look at the most recent results to see what sort of thing they're talking about, as there are references to stratification that aren't relevant to this question. Less quick and dirty would be to look at the AR5 WG1 report, which will give you the state of the science as of four years ago and tell you which papers are the most pertinent. You can then feed those references back into Google Scholar and look at the most recent citing papers to see if anything has changed.