Teamosil said that water levels are rising. If that is the case, I would think that flooding of NYC would be predictable within a range of years. Are you saying this cannot be done?
Does everyone agree with nijato's assessment?
Yeah, he's right. You can't predict these sorts of things exactly. After all, we're talking about weather here. And any predictions need to be based on projections of how much greenhouse gas the world will release each year, which is very tough to predict exactly. But you can definitely predict long term trends and effects that various factors have and make very informed decisions based on those things.
As for NYC specifically, realistically it won't ever go under water. It's worth too much. They'll build dykes and whatnot for real estate that valuable. But it will cost them many billions of dollars to deal with the impact of sea level rise. New York City alone has
600 miles of coastline and 4 of the 5 boroughs are islands. It is almost all built very close to sea level. So, the cost of a project like that would be enormous. They're currently predicting up to
23 inches of sea level rise by the end of the century in New York. That may not sound like much, but it means hundreds of miles of dykes, massive changes to drainage and water treatment systems, etc. And that is just for the sea level rise. The heat in general means much larger demands on its electrical grid in summer, public health problems related to heat, moving critical infrastructure further away from the shore line to make it less vulnerable to hurricanes and whatnot, etc. Just for New York City alone, we're talking about hundreds of billions of dollars fighting the effects of global warming.
As for predicting when, that question doesn't really line up with the facts. Some costs have already begun to show up. It isn't like one day it will be above water and everything will be great, the next it will all be flooded. The water level will raise by a fraction of an inch per year. The very lowest areas will have a bit more damage in storms than they would have otherwise, then maybe they'll start improving drainage systems, then eventually they'll have to build a couple dykes, then a few more, etc. But, by the end of the century they're looking at massive costs from it.
One thing that is important to keep in mind is that AGW doesn't work like we can cut carbon emissions and then the next day everything is back to normal. The effects last many decades. Changes in our behavior today more than our behavior at the end of the century, determine how things will be climatalogically at the end of the century.
But, that's just one city. The costs nationwide will be much higher. By the end of the century they are projecting that nationwide we will face around
$1.9 trillion/year in global warming costs if we do nothing to abate the problem at all.
