Global Warming

[Norseone]

I have a question about global warming. Lets not turn this into a discussion of what is causing global warming, because it is clear it is occuring. What I would like to know is, if the ice caps do melt, what nations will be hardest hit, and how would we best limit the casualties throughout the world?

I have heard about Bangladesh probably being hit very hard, but i cant imagine thats the only place. What would happen to other important costal cities such as New York, San Francisco, Hong Kong, Shanghie, Hamburg, etc. I would imagine that the developed nations would be able to limit the water's intrusion into thier nations, but the developing(and otherwise) world will probably have incredible problems. Is this correct?

 

[carlosMM]

correct - if we stick to the sea level rise only the developing antions with very low relief will be hit first. Bangladesh, Pacific and Indian Ocean island nations, Brazil and neighbouring states.

Ans indeed, the netherlands will 'simply' have to build up higher dams.


Sadly, it is not that easy - the actual notion of a 'global sea level' is nonsense. Lots of factors influence how high the water laps at the coast in any place, inlcuding large currents like the Gulf stream. Now, global warming and the resulting climate change will change these. Thus it may well be that the sea level rises a lot more in one place than another - and this is not really easy to predict!

 

[Mongoloid Cow]

Also, the ocean is not "level" either. IIRC, the Atlantic Ocean is several metres higher than the Pacific (or the other way round) so the effect on global warming may effect certain bodies of waters more significantly than others (although all will be affected in a big way IMO)

Low-lying coastal cities and nations and regions on relatively flat and low land would be drowned. Since much of the world's food and money is concentrated in said reasons, food and money would be very scarce (and it wouldn't be a simple case of going fishing, as the rising sea levels would actually kill off much of the worlds sea life, especially coral and reef environments). Several Pacific island nations (some as large as Tahiti) would be entirely submerged.

 

[Ramius75]

I know if the sea level rise by 3M Singapore will be greatly hit, we r a small country with large population and no place to run. Time to buy a rubber dinky.

Places most hit will be Japan, Taiwan, Indonesia, Phillpines, Sri lanka, All the pacific islands, Hong kong, Netherland, in fact most island countries...

Also with the Democrats moving inland, the red states will be taken away, thats something good.

 

[Akka]

One of the major change is that, with so much addition of cold non-salted water, the Gulf Stream could "plunge", with catastrophic climatic effects for the whole Europe.

 

[Mario Feldberg]

Who cares? The rich will buy new homes on the Himalaya and the poor are always f*cked anyway

 

[carlosMM]

Who cares? The rich will buy new homes on the Himalaya

many of todays rich will aslo suffer - massively.

 

[Timko]

Lets not turn this into a discussion of what is causing global warming, because it is clear it is occuring.

(bolding mine)

I think a few people around here might very well argue with that.

 

[carlosMM]

(bolding mine)

I think a few people around here might very well argue with that.

Yes, some alos think the world was created by a bearded old guy in 7 24 hour days.

 

[Pikachu]

Global warming doesn’t necessarily lead to less ice on our planet. Increased global temperature will probably lead to decreasing ice caps in some places and increasing ice caps in other places. It is hard to tell what the net result will be. Much of the Ice caps are located in areas where the temperature always is far below the melting temperature. Ice will not melt much faster if the temperature is -5C compared to if the temperature is -15C. In many places increased temperature will instead lead to increased ice caps because it snows a lot more when the temperature is close to the melting temperature than when it is very cold.

An effect that is somewhat easier to predict is the thermal expansion of water. Hot water takes up more space than cold water, and since there is so incredibly much water in the oceans, this effect can be significant.

The sea level will not increase very much in any case. The most pessimistic predictions estimate up to one meter higher global sea levels during this century. One meter is serious enough for some places though.

From http://www.climate.org/topics/sealevel/index.shtml:

Among the most vulnerable are countries with large populations in deltaic coastal regions such as Bangladesh, Viet Nam, China and Egypt.

Two populous island nations, the Philippines and Indonesia, have millions who face displacement from their homes from sea level rise. Several small island state nations including the Maldives in the Indian Ocean and the Marshall Islands and Tuvalu in the Pacific could face extinction within this century if rates of sea level rise accelerate. Most of their populations live very close to sea level and a rise of as little as a meter could prove devastating. Even before their lands had become uninhabitable due to inundation some would face loss of their fresh water supply due to salt-water intrusion.

The estimates are only for the mean sea level rise. As several posters have pointed out, the sea level is not the same everywhere. Local changes could be a lot more dramatic than the mean change.

Global warming will also likely lead to more storms, so more and stronger spring tides that temporarily flood low lying costal areas must be expected. This could cause temporary flooding of significant parts of low laying cities like Tokyo, Osaka, Bombay, Madras, Calcutta, Seoul, Bangkok, Dhaka, Karachi, Jakarta, Manila, Shanghai, Tianjin, Lagos, Cairo, Istanbul, London, New York, Los Angeles, Buenos Aires and Lima unless huge flood gates are built.

 

[thetrooper]

Lets not turn this into a discussion of what is causing global warming, because it is clear it is occuring.

Well, do we know that? I would like to examine the evidence. What we do know is that we are depleting the worlds fossile fuels.

 

[carlosMM]

Global warming doesn’t necessarily lead to less ice on our planet. Increased global temperature will probably lead to decreasing ice caps in some places and increasing ice caps in other places. It is hard to tell what the net result will be. Much of the Ice caps are located in areas where the temperature always is far below the melting temperature. Ice will not melt much faster if the temperature is -5C compared to if the temperature is -15C. In many places increased temperature will instead lead to increased ice caps because it snows a lot more when the temperature is close to the melting temperature than when it is very cold.

actually, all our models show otherwise - very few places will get more snow and the icecaps will go all the way (self-enforcing cylce: the less ice the less cooling of the air and the less albedo, means the more melting, means the less ice etc.)

The biggest effect of immediate warming will be a lesser equator-pole gradient, leding to a climate that may approximate late Eocene levels (forested poles!). The problem is that our current action of deforetation and otherwise turning large areas into easily eroded plains and deserts will mean a totally different rainfall, fresh water and cloud distribution. Also, the Himalaya and especially the Tibet plateau will still influence world climate, so even the Eocene is not a good model.

 

[carlosMM]

Well, do we know that? I would like to examine the evidence. What we do know is that we are depleting the worlds fossile fuels.

we know we pump billions of tons of Co2 into the athmosphere that are not part of the nrmal Co2 cylce as they come from 'storage'
we know we pump a whole lot of methane into the athmosphere that wouldn't be there without us and is not part of the normal methane cycles.
we know that glabal average temperature has risen steeply in the last 50 years
we know that even the worldwide deforestation at the time of the neolithic revolution has changed the climate and raised temps through CO2 and methane level increases
we know that Co2 and methane are strong geenpouse gasses.
we know we are pushing the CO2 and methane levels to areas we know from ice cores or the fossil record (microfossils) that indicate a totally different climate then today.


sufficient?

 

[thetrooper]

@carlosMM: I know all that jazz. But the global T varies from ice age to ice age. One steep rise in T could be natural. I fear (and hate) pollution as much as I presume you do. But I sense "The Day After Tomorrow" defeat every time the global warming threads show up.

 

[thetrooper]

The best estimate I could find right now is a rise in the sea level of 20 cm within 2030. The major contribution to this is thermal expansion of the sea (12 cm). Melting of ice (not the great ice caps!) is 8 cm.

Houghton, J. T., Jenkins, G. J. and Ephraums, J. J. (1990): Climate Change . The IPCC Scientific Assessment. Cambridge University Press, p. 365.

This model may be modified by now.

 

[carlosMM]

@carlosMM: I know all that jazz. But the global T varies from ice age to ice age. One steep rise in T could be natural. I fear (and hate) pollution as much as I presume you do. But I sense "The Day After Tomorrow" defeat every time the global warming threads show up.

this is the steepest ever rise, by a fair margin (a bit more than an order of magnitude), and we now know that the increase significantly lags behind greenhouse as emissions.

I expect to see a massive climate shift in my lifetime - ice cores show e.g. ice ages to start 'suddenly', within decades, just the actual ice shields take longer to grow.

 

[Pikachu]

actually, all our models show otherwise - very few places will get more snow and the icecaps will go all the way (self-enforcing cylce: the less ice the less cooling of the air and the less albedo, means the more melting, means the less ice etc.)

I don’t think we have good enough models for how icecaps reacts to changing climate. Ice is a very complicated material. I can see that we have good reasons to fear that global warming will melt a lot of ice, but I am not convinced that it nessesarily have to happen.

And how can the icecaps go all the way? Wouldn’t that demand an unrealistic high increase in temperature?

 

[storealex]

We just had a thread where numerous people chose to doubt human caused global warming. All of these people found themselves faced with superior arguments and left the thread. It's always like this. If we must have this discussion (again), let's do so in the thread designed for it.

 

[carlosMM]

I don’t think we have good enough models for how icecaps reacts to changing climate. Ice is a very complicated material. I can see that we have good reasons to fear that global warming will melt a lot of ice, but I am not convinced that it nessesarily have to happen.

Actually, by now model are getting pretty good -I know, we have a bunch of guys doing the research one floor up

And how can the icecaps go all the way? Wouldn’t that demand an unrealistic high increase in temperature?

Not really - if you go up 1°C but reduce the gradient to half the steepness you get +10° or even +15 at the poles! Now, this means 'just above freezing' for a very large area! It is not the actual poles, but the areas around them where 1 or 5° up or down decide whewther you have year-round snow cover or not! What should happen is that the sea freezes over a lot less, that also a lot less snow falls and that the resulting reduction of albedo leads to a fruther melting. As I said before: we are leaving the ice-age cycle area of the temp/gradient graph and go 'back' into Micene/Eocene!

 

[Pikachu]

Not really - if you go up 1°C but reduce the gradient to half the steepness you get +10° or even +15 at the poles!

15C is very much indeed, but why would the gradient be halved because of a 1 degree increase? Or because of a 5 degree increase for that matter? What is supposed to change the gradient that much?