No Tim, that is counterfactual. It has been rising for a few thousand years, you are correct. But it has been far from steady. There have been periods since the last ice age when it has risen more than others. The Antarctic ice sheets have destabilized on more than one occasion. When that happens, there are periods where they shed icebergs in swarms. They have found deep strata of sand on the bottom of the oceans where the icebergs dumped it from their bottoms as they swarmed out into the world's oceans. As you might not know, the icebergs are going to displace their mass in water, so sea level can rise significantly in a very short period of time. Raising sea level on the order of feet(3.5 meters in one case). No melting required. And this is something that has happened on the scale of years.
Now all but one of the Antarctic ice sheets has destabilized. The remaining one might not remain stable for long. The scientists hadn't really considered its stability in question until recently. Seems that there is more exposure to the ocean than originally thought.
But, you are right. Iceberg swarms might not happen any time soon. There is no reason to think they won't, but it isn't 100% certain they will happen soon. Other symptoms, like the extinction of the ice shelves, bode ill for it to be a long term thing. The ice shelves don't contribute to sea level change, after all, they mainly float on the water. But they do slow the flow of the ice streams that feed them. As the ice shelves have disintegrated, the ice streams have accelerated. A lot. Greatly increasing the odds of iceberg swarms.
To the extent some coastline winds up below sea level it often has more to do with erosion and subsidence than rising sea levels.
Uh Tim, this is bullshit. Winds and currents can cause sea level changes but that is purely a local effect. Not a global one. Not really sure what you are trying to say with that sentence, but it makes little sense. Subsidence might seem to be similar to sea level change as to coastline changes, but that isn't the topic under discussion. And you go all Palin when you mention erosion.
The Zuiderzee Works and such have expanded land out in to areas that were already under sea level
Thank you Captain Obvious. Any idea what it cost to do that? Want to take some guesses? Now how many 3rd world countries are going to be able to invest many times their GDP in such construction? The Netherlands is a fairly wealthy country. Plus, they started this effort more than a century ago and that continued efforts that started centuries before that. Even then, the Zuiderzee effort has consumed a big fraction of their GDP and been the focus of the entire country for decades. Which makes it a pretty dumbass example. India, to pick one country, would have to build many equivalents of that to solve their problems. Which are in many respects far worse than what the Dutch have faced. Without factoring in the cost.
Also new development can slowly move inland.
And, as the older development falls to the ocean, it means they are moving the city.
Which brings us back to square one. Now I suppose it depends on your definition of "slowly". You seem to think the time period of merit is measured in centuries. It isn't. Current projections show a rise of about a meter in a century. Remember that the projections of the rate of increase have been very conservative, the real rate have exceeded projections at every turn. So a meter is the very least that can be expected. And that is with no iceberg swarms. Which can multiply that figure by 3 to 5. A meter rise in a century is a major challenge. Four to five is that much more. If the East Antarctic ice sheet or the Greenland ice sheet decide they want to play the swarm game, well...
So yeah, sea level change isn't an existential threat. If you ignore what has happened in the past and what is happening now. If you assume things will stay the same as they have been in the very recent past, ignore all of the evidence that it won't and assume that, if anything, the changes that have happened over the past couple of decades will reverse.
I suppose if you break out the unicorns and the fairy dust, miracles can occur. Betting on your fondest fantasies might work for you, but that track record is terrible.
I'd suggest you educate yourself on the issues, but you seem to be impervious to actual facts. So... |
