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Carbon Dioxide is a tiny component of our atmosphere that helps warm the earth to the comfortable temperatures we are used to, but it also can cause a lot of damage when there is an excess. The gas is measured in parts per million or (p.p.m.) Having too much Carbon dioxide in our atmosphere is very dangerous because it allows sunlight to stream in, but it does not allow heat to radiate back out. "During the last ice age, the atmosphere's CO2 concentration was just 180 p.p.m., putting Earth into a deep freeze. After the glaciers retreated but before the dawn of the modern era, the total had risen to a comfortable 280 p.p.m. In just the past century and a half, we have pushed the level to 381 p.p.m., and we're feeling the effects. Of the 20 hottest years on record, 19 occurred in the 1980s or later. According to NASA scientists, 2005 was one of the hottest years in more than a century."
"Icebergs don't raise sea levels when they melt because they're floating, which means they have displaced all the water they're ever going to." Unlike these icebergs, ice on land, such as Greenland, pours into oceans that are already rising because of the expanding warm water. Greenland alone could raise the sea level 23 ft. This would cover a lot of the coastal region of Floridia and most of Bangladesh. "The Antarctic holds enough ice to raise sea levels more than 215 ft."
One of the main reasons the surface area of the ice is shrinking is because as the bright white surface shrinks it changes the relationship of the Earth and sun. Polar ice reflects 90% of the energy it recieves. "The more energy it retains, the warmer it gets, with the result that each mile of ice that melts vanishes faster than the mile that preceded it." Permafrost is land that has been continually frozen for two or more years, but most permafrost has been frozen for much longer -"since the end of the last ice age, or at least 8,000 years ago." The permafrost contains layers of partically decayed organic matter. This stuff is rich in carbon. In areas where the soil is getting warmer such as high-altitude regions of Alaska, Canada and Siberia, the permafrost is melting and turning into methane and CO2. This can lead to more warming and permafrost melting. David Lawrence of the National Center for Atmospheric Research says there may be 200 to 800 gigatons of carbon in the soil.
The Gulf Stream is what keeps Europe's climate relatively mild. When it is cut off, the temperature will plummet. The Gulf Stream works because the warmer, more salty water which is ligher floats on top of the more dense colder water. As it reaches Europe it gets colder and more dense it flows back down south where it crosses under the northbound Gulf Stream until it reaches the tropics and begins to warm up again. The system will continue to work as long as the water stays salty enough, but with the freshwater that is being added in, the system may break down.
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