Quote:
Originally Posted by Pinner
If much of N.America and Europe and well much more of the world is covered in ice/snow, a lot more of that energy will be reflected back into space rather than be absorbed as it is now. That's what my simple minds thinks.
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Sure, snow coverage affects albedo, that's one of the factors. And if you get enough, you can shift into a different balance where the other warming factors aren't sufficient, and be in a global ice age. Which would be bad.
But the increased snow coverage is an effect, not a cause, because of shifts in ocean currents or whatever.. so the energy that would have normally gone to keeping NA and Europe warm necessarily has to go somewhere else first in order for it to get cooler in NA and Europe.. then the snow coverage increases, changing things further, etc.
Positive and negative feedback loops.
You also have more CO2 in the atmosphere, and CO2 is a greenhouse gas so less of that reflected energy would make it to space, more of it would be contained within the earth's system, decreasing the effect of the increased albedo.