Anticipated Sea Level Rise May Be Faster Than Previously Thought - BBC

[hatrack]

Current sea level rise projections could be under-estimating the impact of human-induced climate change on the world's oceans, scientists suggest.

By plotting global mean surface temperatures against sea level rise, the team found that levels could rise by 59% more than current forecasts. The researchers say the possibility of greater increases needs be taken into account when planning coastal defences. The findings have been published in the online edition of the journal Science.

The team from Germany and the US found that for the timescale relevant to human-induced climate change, the observed rate of sea level rise through the 20th Century held a strong correlation with the rate of warming.

When applied to the possible scenarios outlined by the Intergovernmental Panel on Climate Change (IPCC), the researchers found that in 2100 sea levels would be 0.5-1.4m above 1990 levels.

EDIT

http://news.bbc.co.uk/2/hi/science/nature/6179409.stm

[Dead_Parrot]

1. no shit... nt

[XemaSab]

2. Forgive me if I'm saying something dumb here

but it seems to me that these models are overly cautious in estimating the rate of change. It makes no sense to me at all that the climate (and the sea levels) should continue changing at an even rate instead of "jumping" suddenly as it has in the past.

Hasn't it been "proven" (insofar as such a thing is possible) that ice ages do not happen slowly but very, very, very quickly? Why should the opposite not also be true?

To get into supposition-land, doesn't sea ice, at its very edges, exist in a very delicate state where a few tenths of a degree change in the water surrounding it makes the difference between totally melting and completely freezing? There will be some buffering inherent in the structure of the ice, but after a few days of slightly different temperature the ice would either totally disintigrate or not?

So when we're talking about Greenland and Antarctica, any collapse of those ice masses could be VERY VERY VERY rapid, and not the slow change predicted by this model?

You read stuff like this, and it's like, "Oh, the seas will be a foot and a half higher up the beach in 100 years. Yawn. I wonder what's on TV?" But the reality is either it won't be a big deal at all and we'll laugh about how silly we were, or we'll be TOTALLY HOSED, depending on whether we hit the tipping point. Which nobody knows anything about, or even if it exists.

Happy Holidays!

[phantom power]

3. Yeah.... I'm voting for "totally hosed."

[kestrel91316]

4. Sadly, I concur.

[intaglio]

9. Consider the following

Sea level is not constant; high atmospheric pressure can drop the sea level under it, low can raise it: then there are the tides to consider. If you realise this then a 0.5m (18") mean sea level rise can add exponentially to the surges we see normally let alone hurricane/typhoon storm surges. Imagine if the sea had been 18" higher during Katrina! Check out what would happen to Bangladesh, or Holland or the Amazon basin if sea levels were "just" 18" higher

There are other things to consider; rates of erosion, saline hydrostatic pressure on fresh water aquifers, hydrostatic loading on (tectonic) plate margins ....

[XemaSab]

11. Yeah, but it will be incremental over the next hundred years

So it wouldn't be a big thing happening all at once. It would probably be so gradual people would forget how things used to be.

[NNadir]

5. The striking thing is how many models proved to be way over optimistic.

[hatrack]

6. I wouldn't say "over optimistic" - but science is a fundamentally conservative mindset

Not in the bullshit late-20th century American sense of the word "conservative", of course. But in more general terms, prone to understatement, tending to let readers infer implications not stated by the results, etc.

[Odin2005]

8. Science, in a way, has to be conservative in order to protect against kooks.

[Morgana LaFey]

10. Right -- again and again they're wrong because they were too

conservative, as most scientists are wont to be anyway.

I've felt (intuitively) for a while now (several years) that we've probably already reached that infamous tipping point of no return AND that there would be an acceleration of effects, as well as feedback loops (is that the term?) by which I mean things which feed into the mix and make it even worse. An example of the latter is the permafrost melting and releasing even more greenhouse gas, which makes the whole thing worse and faster.

Screwn, I think, is the technical term for where we are.

[rman]

7. The climate is a non-linear system,

mathematical theory (chaos theory, complexity theory) predicts that large and abrupt changes are likely to occur.

Al Gore explains this in "An Inconvenient Truth".