Oh, sh*t, or, this is why it's called "Global *Climate Change*", not 'warming'

[purpletigron]

First observational evidence that the North Atlantic Conveyor ('Gulf Stream') is weakening. "Computer models have predicted that if it turned off completely, Europe would cool by perhaps four to six degrees Celsius."

Comments

[purpletigron.livejournal.com]

OK, I've now been able to access the 'News and Views' response to the study:

During a cruise in spring 2004 from the Bahamas to the Canary Islands, on board the British research vessel RRS Discovery, the team measured water temperature and salinity along a latitude of 25º North, taking samples roughly every 50 kilometres. They then calculated from the density and pressure differences between each sample, the volume and velocity of the circulation at various depths, assuming that from coast to coast the balance of water flowing north and south must be zero.

Similar measurements along the same latitude were previously made in 1957, 1981, 1992 and 1998. But until now, the data never showed any significant decline in circulation. "In 1998 we saw only very small changes," says Bryden. "I was about to give up on the problem."

So I see where your 'one result' comes from - sorry about before!

[artela.livejournal.com]

That's OK - apology not necessary.
As a scientist (in training) I cannot accept results such as those as there is no way to tell if the readings are anomolous (ie. they caught it in a bad season) or not - as I said, what is needed is continuous monitoring. Personally I think the results are probably what they're being billed as (due to the melting greenland glaciers, melting arctic polar ice cap, etc - which should lead to a drop in temperature _and_ a drop in salinity), but without the correct proof it is dangerous to assume that a result is what we want it to be to back up other theories.

[purpletigron.livejournal.com]

Oh, but it is - I'm a scientist too, a physicist. I have long railed against poor science journalism, and this is another example. There's a big difference between 'based on 50 years of observations' and 'based on a few spot samples over 50 years, where only the last one shows any change'. Grr.

Scientifically, I quite agree. However, politically, I think we need to follow the 'precautionary principle' - start planning for plausible difficult cases (not the same as 'worst case scenario').

[artela.livejournal.com]

Oh I absolutely agree on the political "we should do something" front :-)
It's just a shame that we can't force the world's largest problem to do something about it - it makes our own small efforts in this country seem so insignificant :-(

[purpletigron.livejournal.com]

I have to keep reminding myself that I can't single-handedly change the world. I do what I can do, I try to persuade my friends and family to do what they can do, I lobby my elected representatives to do what they can do... Remember, only half the USA are Republicans, and there are a lot of USA residents who want to do more. So, if the UK is setting a good example, we're helping by more than just our direct efforts... Also, we're 'heavy emitters' (four times the sustainable global level, even without any personal flights).