Over on retrieverman, the post on the talking gorilla KoKo (she uses sign language) got a bit off topic and strayed to global warming. I want to interrupt the series here on thepdkc to comment on global warming.
http://retrieverman.wordpress.com/2009/12/04/koko-and-all-ball
Is it a good thing, or a bad thing?
Depends on if you ask a guy while he is shovelling snow in the winter or while he is mowing the yard in the summer, doesn’t it?
If the ice sheet is getting thinner, is it because more ice is melting during the summer (warming) or because less snow is falling in the winter (drying – less falling moisture).
Drying of the weather – less rain, less snow, less moisture, is different than temperature change. AFAIAC, drying is a huge problem – in many areas, seedlings die without enough rain in the spring to support them until their roots are deep enough.
Our cereal grains are annual crops – they die in the fall, and most be regrown from seeds every spring (unlike trees that can live for thousands of years).
Warming itself doesn’t worry me. As retrieverman said, in the 70s there was a big scare over a coming ice age – and a gasoline shortage – where we would be cold and out of fuel.
As for rising oceans from icebergs. No. Melting ice and snow ON LAND can cause water levels to rise. But the icebergs are like popcorn, bigger than what they were before they were popped, but weighing the same.
Melt an iceberg and the water from it will fill about the same area that that the iceberg did. Terrierman mentions that this morning as “displacement”, as why concrete ships float.
AFAIK, you could melt the entire north polar icecap and the ocean level will not rise any. If I remember right, ice takes up MORE room than water – but I doubt that melting the north polarcap will DROP the ocean level, because some of the iceberg are floating above sea level. I think it evens out.
Now if melting the north polar ice cap caused Greenland to melt, it might raise ocean levels a little. And IF that spread to the antarctic (south pole) and IF it could melt the south pole – that I do believe would raise ocean levels a bit.
The north pole is little more than a giant ice cube held in place by a few islands.
But the south pole is a continent that is covered with ice and snow.
Warmer ocean water could melt the north pole – which would be very good for shipping! (AFAIK, no animals live on the polar ice cap, although I guess some sea mammals might go there some part of the year).
But to melt the south pole, air temperature must be warmer. (Penguins and some seals live along the coast – but no animals live inland).
So, would melting the north polar ice cap hurt anything? Or would it help temperature?
As for melting icecaps raising water levels. Get out a glass, fill it with ice, pour water in it, cover the top of the glass with something flat like a saucer or small plate so that the glass is completely filled to the very top but no ice bobs above the surface, dry up all the water split around the glass.
As the ice melts, does any of it overflow the glass? That will tell you about melting icebergs in the ocean.
PS – you might have to sop up condensation from the glass – this is NOT water flowing out of the glass. It is the water that jumps out of the air to cling onto the cold surface of the glass.
Doghome 