Global Issues Of The 21st Century

1400 Words Dec 10th, 2016 6 Pages
One of the most pressing global issues of the 21st Century is the contribution of humans to climate change. To understand human impact on the Earth it is crucial to understand the basic climate science of glacial periods and the greenhouse effect. For its entire lifetime, the planet has gone through cycles of glacial advance and retreat. More simply, the Earth warms and cools in cycles, the last of which we call the Ice Age. These cycles are completely natural, expected, and simply a part of life on Earth. The greenhouse effect directly explains how this warming occurs. The Earth is heated by radiation from the sun; sunlight enters the Earth’s atmosphere, warms the earth, and is reflected back out into space. The Earth’s atmosphere protects the earth from freezing, trapping heat from the sun. Without the greenhouse effect, the earth would be completely frozen. Since the start of the Industrial Era in the mid-1700’s the massive industrialization of human society across the globe has led to tremendous increase in the release of Greenhouse Gases such as CO2, methane, nitrous oxide, and halocarbons. These gases trap the heat from the sun, raising the temperature of the planet much faster than normal. Most of this output of gas has been in the past 40 years. This rapid output has caused unprecedented change “which include changing weather patterns, rising sea level, and more extreme weather events.” (1) By artificially increasing the amounts of gases, humans have raised…
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