Quote:
Originally Posted by Rino
Okay now. I have a lot of questions on this subject. So I will post them one at a time until they are all answered responsibly and accurately. I am no scientist. I am just a cop. That being said I am neither stupid or ignorant as to common sense. So rhetoric will not fly here.
First question.
According to the scientists that were just on the show "Expedition Alaska" one of the reasons and effects of global warming is the melting of sea ice in Alaska and around the world, and as such that warms the planet because the sea ice in Alaska reflects 70% of the sunlight back into the sky and thus raising surface temperature even more. Also as was referenced earlier in this thread the ice in the north and south is apparently thicker than it has been in the past.
How can this be true? For ice to reflect that much light 70% of the world would have to be covered in ice. As Alaska and the other areas that are covered in ice are minuscule in proportion to the non ice covered parts this effect would be almost unmeasurable.
If you are a skeptic and do not know, then just say that you do not know. Same goes for a proponent.
If you are just going to respond with insults then please shut your mouth. The idiocy is not needed here.
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You are talking about albedo - the amount of sunlight a body reflects
Perhaps the show you watched didn't explain it clearly. I think they were trying to say that the sea ice in Alaska will reflect 70% of the light hitting the sea ice in Alaska - not the light hitting the whole world.
Generally - fresh, flat snow will reflect 90% of the light hitting it. Bare earth will reflect much less - perhaps less than 10%. The figure of 70% for sea ice sounds about right. The average albedo for the whole Earth is about 30% - ie 30% of light hitting the planet from the sun is reflected.
Reflected light is also reflected heat. If AGW causes surface temperatures to rise and ice/snow to melt, it is predicted that the loss of snow will reduce the earth's albedo, creating a feedback mechanism that thereby further increases warming. However - higher temperatures may also result in more water vapour and more clouds and hence an increased albedo - leading to some amount of cooling.
Which scenario is correct? I don't know - but it is one more factor in the complexities of global climate that suggest it is a good idea to try to limit the emissions that may impact on global climate.
Albedo is explained well here:
http://en.wikipedia.org/wiki/Albedo