I was watching a show on National Geographic today that was talking about the formation of the Earth and how the climate has changed during that period. One of the things that struck me was one of the folks interviewed saying that the last 10,000 years of Earths climate has been one of the most stable periods know…if not THE most stable period known. I have no idea how accurate this is (seems to me the Earth was pretty stable during some of the dinosaur periods since they lasted for millions of years), but one of the things that struck me was this guys claim that within the next 15,000 years we will have another severe ice age period again.
Again, I have no idea how accurate this was (he claimed that even with GW this would happen…seems like BS to me, but I’m no climate scientist), but it got me thinking…what would we do if we DID go through another ice age? In the last major ice age New York city, for instance, was pretty much under hundred of feet of ice…and everything north of there as well. Much of Europe was in a similar way. What would we do? What COULD we do? I assume much of Canada would need to be abandoned, and the cities basically buried under the ice. Would a major ice age cause our civilization to completely collapse? Would it pretty much erase evidence of human habitation above the glacier line?
How long would it take for the glacier line to reach New York and London? I imagine that it would take hundreds of years, if not thousands. Plenty of time to shift populations. And if the world cools, then places like the Sahara should get rain and bloom; I recall a TV programme saying it used to be a savannah. IIRC the fossil record shows this. I imagine parts of the US like Arizona would be the same. Basically, just as the temperate zones have been shifting away from the equator, so they will shift back towards it again. Remember that in Roman times, northern Africa was the granary of the Roman world.
It will be very interesting to see what happens if Australia cools.
Not really. Remember the famous frozen mammoths with flowers in their stomachs ? As I understand it, major climate change can come in just a few years.
The reversal of interglacial warming (causes of which are not thoroughly understood) would require first the reduction of warming, a period of relative stasis, each probably measured in decades or perhaps centuries. Then the drop in temperature and the resultant reversal of the dynamics of heat transfer in the oceans. more decades, maybe more centuries. Then the glaciers begin to sweep down. Moving, of course glacially. Meters per year, in most cases, but perhaps hundreds of meters per year in a few instances. Eventually the continental shelves begin to appear as new coastal areas. The loss of absorptive sea surface accelerates the process of cooling. The release of seabed methane begins to reverse the cooling process. This also is not a thoroughly understood dynamic.
Forested northern areas become tundra. The mass of ice reflects more sun, and wind patterns change radically over decades. Birds become extinct, and flourish in widely divergent patterns. Siberia, and Canada face extreme agricultural challenges, and the center of Europe (All those picturesque alpine valleys) fills with ice. In western North America, a great Ice Sheet begins to grow down from the Mountains, and the Mississippi Valley begins having annual flooding of massive proportions from summer melt. Summer melt begins cooling the Gulf of Mexico, changing the driving force of the heat tractor that keeps northern Europe so much warmer than America and Asia. Of course, by now it’s been happening for three or four hundred years, and wars have been fought and lost over the best of the new agricultural land. Armies, after all move faster than glaciers.
Erm…yeah, like if a couple meters of ice would feel so quickly…
Mammoths have been living in polar areas forever, those who are found are the result of accidents, such as dying in a body of water that eventually froze, etc.
It would really take more than a few centuries (or even thousands of years) for ice sheet to be threatening agricultural areas, but yes : that probably will happen. Although humanity faces much more challenges, one of them is to sustain its own population. Just keep in mind that human population has doubled in only ~50 years, and that current fossil fuels (and arguably uranium) won’t last until 22nd century…major changes are going to occur by then, much more important than any ice age could in a few years.
Was watching the same show before I left for work. My first thought was that we’ll be knocking on Mexico’s door. “Hi Mexico! Sorry about that whole border fence and all… We brought cookies! We can haz warm dry land?”
This is a bit tongue in cheek, but it’d actually be a lot more forceful and violent, and you’d see it the world over.
Right now the civilized countries are civilized precisely because we don’t have to fight for the bare necessities which we view as required to maintain our societies. The United States fights wars which tangentially affect our security (with differing opinions on each war), there was a time when we fought wars for what we viewed as essential lands and resources. Those wars are all-or nothing wars, they’re violent, and they throw out the conventions that our international system has built up over the past decades.
Nope. All the evidence suggests that the change happens extremely rapidly. Just have a look at the last cold snap. Temperatures seem to have plummeted 2-3^oC in just a coople of centuries at most. In reality we don’t know how fast it actually happened, it may well have been in a matter of decades. But certainly claiming that it will take millenia for such changes to occur isn’t true.
So?
Utter bollocks. Nobody of any credibility makes such lunatic claims.
Agreed. There will be technological changes that will make the green revolution or eletcronics of the past 100 year slook like the inventio of the flint scraper.
There is a reason why the world population has doubled in 50 years and yet the standard of living is higher than at any stage inhuman history. That’s because technology manages to overcome any problom that we encounter.
With our geothermally- and passive-solar-heated cities and our greenhouse agriculture, and our cities built into the bedrock of the mountain peaks, The True North Strong and Free comes into its own.
SF novel Fallen Angels, by Larry Niven, Jerry Pournelle and David Flynn, is set in a near future where a new Ice Age has made Canada uninhabitable and the U.S. less pleasant. This is blamed on the environmentalists, who got into power and put through measures that successfully put a stop to anthropogenic global warming just when it would have come in useful!
I don’t know about the rest of you, but I’m putting my house on rollers and letting the advancing ice sheet push it south. It’s called migrating – birds do it all the time.
I know I’m going to get slammed for this and be called an anti-global warming nutcase but I was under the impression that we are currently in an interglacial period and that each one of those periods is warmer than the last. In the short term, yes, we are warming up and atmospheric CO2 is higher than any time in the last couple hundred thousand years, but will that preclude us from experiencing another ice age?
Well, yes, it might – or, at any rate, throw off the schedule. Remember, the changes in the atmosphere caused by the Industrial Revolution are without precedent in Earth’s history.
