A student from Brazil had a questions for scientists.
Olivia: My question is, what are the consequences of polar melting?
EarthSky asked Ginny Catania, a polar research scientist at the University of Texas.
Ginny Catania: It’s a really important question right now, because the Earth is warming due to man-made activities. And the polar caps are very susceptible to that, because if you put ice in a hot environment, it will melt.
She said polar ice caps could dump as much as 60 meters of cold water into the ocean.
Ginny Catania: Even in Rio, in Brazil, you’ll have a big impact if you have that much sea level rise. You’ll have waterfront incurring inland quite a bit, and it can have a large impact on many cities around the world.
Catania said it’s tricky to predict how warming, rising oceans will affect the very complex system that is our Earth.
Ginny Catania: A lot of unknowns still exist. But we do think there will be impacts to weather patterns, sea level rise, loss of habitat, and warming in the Arctic.
Consequences will be felt all over the world.
Ginny Catania: We’re all so intimately linked, and it kind of doesn’t even matter where you’re from anymore.
Our thanks to the Monsanto Fund, bridging the gap between people and their resources.
Our thanks to:
Ginny Catania
Research Scientist, Polar Studies
University of Texas
Austin, Texas
Basically if the polar caps melt, the sea level rises. Earth warms up. Then warmer oceans will cause more evporation which will cause more cloud cover. This in turn will cool the Earth and then cause a very cold period on Earth. The Earths temperature is not constant. And say if it did rise at a constant rate by .4 degrees in 10 years. That should mean 4 degrees in 100 years and 40 degrees in 1000 years. A forty degree difference is pretty imposible i would think.
Orion,
Don’t forget that water vapor is also a greenhouse gas, so increased ocean evaporation can also lead to more rapid warming as more heat from Earth gets trapped in the atmosphere. There is no evidence that increased cloudiness will lead to a ‘very cool period on Earth’. Also, there is evidence that temperatures will increase about 4 degrees in 100 years. Beyond that, it is difficult to predict temperatures because we don’t know how humans will respond to the climate problem and mitigation can reduce warming significantly. I would not however agree with you that a 40 degree temperature change is unlikely. Look at Venus. Venus has a ‘runaway greenhouse effect’. Venus used to have oceans, but now it has a very dense atmosphere and a surface temperature of about 400 degrees. Venus is a lot closer to the Sun, but provides an important example of one possible future scenario.
THe northern polar region has meslted in the recent past. Floating ice will not cause a rise in water levels. Thawing will allow passage by ships through the area, greatly cutting fuel needs because of shorter trips.
In order to melt the southern ice cap, it will take much more than a couple of degrees warming as the southern polar region stays well below freezing, year round. It should be noted that palm and other tropical plant fossils and remains have been found under the ice there. That area was once warm. Who knows where it was relative to the polar apex at that time?
Warming of the globe would allow farming on much more northern lands. That would allow us to increase food supplies. (Some experts think we could feed 29 billion folks now)
I do not think that global warming would cause many problems at all. That is, it the golbe were warming. It seems as though we are actually cooling right now.
Our real problems will be economic and cultural in the foreseeable future.