Just suppose that it is demonstrated that we’re in a long-term uptick in global temperature but that man has nothing to do with it. If you need a limit, say not enough to melt the Antarctic or Greenland icecaps.
What could we do? What should we do?
Should we let cities like New Orleans, Venice, or London drown?
I’ll start by saying that we should continue to move away from fossil fuels, particularly major users like power plants. Fossil fuels tend to be dirty and smelly.
Well, we should then give up on any attempt to stop global warming to begin with; if there’s no anthropogenic global warming then our understanding of the climate and probably several laws of physics is severely lacking. We should also despite what the OP says assume that the polar ice will melt, because in this scenario we can have no idea how far it will go; our climatological models have just been proven nonsense.
As for what else we should do, building barriers against the ocean in low lying impoverished areas over the world like Bangladesh comes to mind. They can’t afford to themselves, I think, and moving that many refugees is likely to be a disaster in any number of ways. Assuming that they aren’t stopped at the border and left to die; any target country for them is likely to be unable to support them.
Stock up on seeds for various crops; there’s going to be a lot of replanting going on as land becomes unsuitable for one type of crop and more for another.
We should in general prepare for a worldwide famine and economic collapse; a worldwide combonation of the Dust Bowl and the Great Depression. How one prepares for a disaster of that magnitude, I don’t know. In fact, we should mostly act just like we should in the real world, because anthropogenic or not, not much is going to be done about global warming until it’s far too late. About the only personal recommendation I can give is don’t have children; we’ll have a hard enough time feeding the people already here, and the future isn’t likely to be a pleasant place to live.
WRT to rising sea levels, the real danger GW presents is not that it will melt ice that is now above sea level, but that it will raise the average temperature of the whole world ocean. A given mass of warm water occupies more volume than an equivalent mass of cool water.
If we’re not causing it, that doesn’t mean we shouldn’t try to do something about it. The infrastructure of human civilization is much more brittle and vulnerable in the Industrial Age than it would have been the last time there was a natural warming cycle. Cutting global CO2 emissions would at least help.
Not necessarily. It could be the secret undersea oyster kingdom that’s pumping out climatologically significant amounts of greenhouse gases, rather than us apes. Such Molluscogenic global warming, or MGW, could fill in for AGW, without requiring a rewrite of the laws of physics.
I am reminded of Fallen Angels, a 1991 SF novel by Jerry Pournelle (you’ve heard of him – he strongly resembles a Buchananite paleocon except that he has a brain), Larry Niven and Michael Flynn. Environmentalist technophobes (the terms appear to be synonymous in Pournelle’s world-view) gain political power in the late '90s and succeed in forcing everyone to cut greenhouse-gas emissions. Shortly thereafter, Earth enters a new Ice Age that, among other things, renders Canada uninhabitable. The environmentalists are excoriated for putting a stop to anthropogenic global warming just when it would have come in useful!
Looking backward, we can only wish we had such troubles. :rolleyes:
Well, that, and the changes in currents they are creating. The most serious, in terms of effect on human civilization, might be the shutdown of the Atlantic Conveyor and the Gulf Stream, and the resulting loss of Europe’s agricultural productivity and overall habitability.
If Global Warming occurs, and there is only a minor influence by humans, then we can expect sea level rises of 29 meters.
So, our plans for New Orleans are . . . unimportant. New Orleans is below current sea levels. Miami, New York, and any port city you ever heard about is pretty much tidal reef.
I predict folks will move inland.
Tris
That’s if the polar caps melt, isn’t it? Which I specified was not the case.
Well, It seems to me that either it gets warmer, or it doesn’t. Last time it got warmer, the sea was about that much higher.
Imagine what you wish, though. By the way, “Capitol Hill” in Washington DC. is 65 feet above sea level, although the White House is only about 34. Tailor your imagined changes to the effect you desire.
“It was a woman drove me to drink and I didn’t even have the decency to thank her.” ~ W.C. Fields ~
Even if humans didn’t create the warming we might be able to intentionally reduce it. Perhaps we could encourage certain kinds of pollution with dust particles that reflect sunlight, or, if we really wanted to spend a lot of money, put reflecting objects into orbit.
Would reflecting objects actually work? Wouldn’t they reflect until they heated up sufficiently and then just re-radiate?
A reflective object reflects even when it’s hot and radiating (unless and until it melts). The point would be to reflect some of the sun’s light back out into space.
Reflected objects would not work, but not for that reason.
Just putting up enough reflective objects to reduce solar irradiation by a hundredth of a percent would be more than all the national space programs to date put together. Then you have to ask, “Gee, wouldn’t that make it kinda crowded for any other sort of space program?”
Tris
That effect is utterly trivial. Most of the water in the ocean is just above freezing. Raising its temperture by 5 degrees C (a worst-case global-warming estimate) from 2° C to 7° C would increase its volume by a whopping factor of 0.999941/0.999902 = 1.00003904 (i.e. enough to raise sea level about 40 cm, if we grossly overestimate the average ocean depth at 10 km).
By comparison, melting Greenland would raise sea levels by about 7 meters.
wait, warm water takes up more space than cool water?
I thought as water cooled to freezing, it expanded. Isn’t that why freezing a bottle of water can cause it to burst?
Water reaches a maximum density at 4°C. Warming or cooling it from that temperature causes it to expand.
A given mass of ice takes up more space than an equivalent mass of liquid water because of the crystalline structure of ice; but for liquid water, colder = denser, warmer = less dense.
Ah, well, the solution is simple, then: Before it melts, scrape all the ice off of Greenland and Antarctica and shoot it into space! 