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Global Warming and Greenhouse Warming By: Kate Bowen. Global Warming : An increase in the average temperatures of the earth’s near surface air and oceans Over the past century, the temperatures have increased 1.33 +/- 0.32 degrees Fahrenheit.
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Global Warming: An increase in the average temperatures of the earth’s near surface air and oceans Over the past century, the temperatures have increased 1.33 +/- 0.32 degrees Fahrenheit
Greenhouse Effect: The heating of the surface of the earth due to the presence of an atmosphere containing gases that absorb and emit infrared radiation • The Earth receives energy from the Sun in the form of visible light and nearby wavelengths • Close to 50% of the sun’s energy is absorbed at the earth’s surface • The other sunlight (solar radiation) is reradiated back into the atmosphere as longer-wave energy (heat) • Greenhouse gases absorb this heat and trap it in the lower atmosphere causing the earth’s temperature to rise
The Earth’s most abundant greenhouse gases are (by contribution to their effect): • Water Vapor (H2O) contributes 36 -70 % • Carbon Dioxide (CO2) contributes 9-26% • Methane (CH4) contributes 3-7% • Ozone (O3) contributes 3-7%
The largest Anthropogenic (human-produced) greenhouse gas is Carbon Dioxide, which is said to contribute the most to additional absorption and emission of thermal infrared The rise is CO2 levels is mostly contributed to the burning of fossil fuels and land-use change
Most significant potential consequences of global warming: • Glaciers will melt more and more • Positive feedback loops: Glaciers are more reflective than the earth, so when they melt, more of the sun’s heat will beabsorbed. Also, as the atmosphere is warmed, the amount of water vapor increases • Sea levels will rise • Wild land fires • Affects on wildlife – polar bears
Critics of Global Warming: • Decreasing the level of CO2 harms our industry’s ability to produce and could really hurt our economy • Previous weather fluctuations (Medieval Warm Period and the Little Ice Age), is not proven to be anthropogenic • It is real, but not a crisis. More people die each year from excess cold than from excess heat • Kyoto Protocol: Exemption for developing countries, and China and India’s gross national CO2 emissions now exceed the US