Apr 29 2010
Scribe Post – The Effects and Evidence of Climate Change
We always hear a lot about “Global Warming” or “Global Climate Change,” but is there even any solid evidence to back it up? The truth is that, even though the idea that global climate is changing at an unnatural rate because of human activities is still not 100% proven to be fact, there have been a lot of scientific observations that make it fairly obvious that we’re having at least some effect on the global climate. In class on Tuesday, we discussed this evidence of an unnatural increase in global climate and the possible effects it could have.
By looking at this graph of the level of the temperature anomaly over the past 140 years, one can see how the earth has now reached record temperature levels. In fact, the first decade of the 21st century has been the warmest on record.
More evidence supporting the theory of global climate change can be found in the downtrend of the average thickness of glaciers and polar ice caps. Glaciers that exist high on the peaks of mountains and in other cold areas the world over have been shrinking at record rates, further suggesting that the global climate is increasing substantially. In South America and Asia, this loss has been particularly rapid and could threaten the water supply for millions of people. Also, the apparent increase in global climate has led to what seems to be a substantial decrease in the size of polar ice caps. Since 1970, it’s projected that 10 % of Arctic ice cover has been lost. Even though the melting of Arctic ice caps wouldn’t cause he sea level to rise because it’s already in the ocean, the melting of huge inland glaciers like in Greenland and Antarctica could very likely cause substantial increase in ocean levels, devastating coastal cities and coastal freshwater aquifers in the process. Finally, this loss of ice and snow cover can lead to a positive feedback loop in which the problem adds to itself in making the effects of climate change worse. Since snow and ice have higher albedos than water and soil, they reflect more heat energy from the sun and keep the earth cooler as a whole. With glaciers and ice caps melting, more heat absorbent water and soil is being left behind, merely exacerbating the effects of global climate change.
http://www.everything-ice.com/images/LOW-E-Albedo-Chart.jpg (A chart that shows the reflectivity of substances due to the albedo effect)
More evidence supporting unnatural climate change lies in the cold tundra and taiga biomes the world over. In these areas, the frozen layer of soil known as permafrost that lies over 1 meter under the surface has begun to thaw for the first time in about 11,000 years, both reducing these biomes into muddy marshes (or thermokast ponds) that the wildlife isn’t adapted to living in and releasing loads of methane gas that have been trapped in the frozen soil. Methane gas is the most potent primary greenhouse gas next to nitrous oxide with a warming potential that is 23 times that of carbon dioxide. Thus, as permafrost melts and methane is released, it seems that the rate of global climate change will continue to increase as well.
Lastly, increased acidity of the world’s oceans has been observed, most likely as a result of the increased level of carbon dioxide in the air from human activities. As the temperature and acidity of the earth’s oceans rise as an apparent result of global climate change, the ocean could stop being a suitable habitat for organisms with calcium shells and coral reefs could be destroyed as a result of “bleaching.”