Climate Change - Moreover, most scientists also agree that...

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Moreover, most scientists also agree that the present trend of climate change is mainly due to anthropogenic (human-caused) influences. Glass allows shortwave radiation to pass through it , but not longwave radiation. Radiation from a very hot object like the Sun is shortwave greenhouse gases within the Earth's atmosphere allow shortwave radiation from the Sun to be transmitted to the Earth. o This shortwave radiation is absorbed at the Earth's surface, and then reradiated back to the atmosphere as longwave radiation. greenhouse gases maintain balance where just enough heat is trapped to keep the planet warm, but not too warm human activity is leading to increasing amounts of greenhouse gases in the atmosphere The ability of greenhouses gases to change the balance by reducing how much thermal energy exits is what global warming is all about The percent of incoming sunlight the Earth system reflects (the Earth’s albedo) is a key climate factor since whatever is reflected can’t go on to warm the planet Rising temperatures may, in turn, produce changes in weather, sea levels, and land use patterns, commonly referred to as “climate change.” o Because snow and ice are so reflective, scientists have long expected that melting of snow and ice in the polar regions will accelerate climate warming by reducing the Earth’ albedo. ... " Water vapor is the most abundant Greenhouse Gas and o varies not only over time, but also from place to place. Warm air can hold more water vapor than cold air. OTHER GREENHOUSE GASES o Methane (CH 4 ) is released by decaying and burning plants as well as by livestock as they digest plants. Methane is also released through fossil fuel combustion and paddy rice production. o Nitrous oxide (N 2 O) is emitted by our cars and by the agricultural practices when nitrogen is used to fertilize soils. o Fluorinated Gases , such as hydrofluorocarbons, are synthetic, powerful greenhouse gases that are emitted from a variety of industrial processes. These gases are sometimes used as substitutes for ozone-depleting substances (such as CFCs, HCFCs, and halons that were used for refrigeration). These gases are typically emitted in smaller quantities, but because they are very potent (their ability to trap heat is high) gases, they are sometimes referred to as High Global Warming Potential gases. WHY ARE ATMOSPHERIC LEVELS INCREASING? o During the past 20 years, about three-quarters of human-made carbon dioxide emissions were from burning fossil fuels. The Earth’s positive imbalance between emissions and absorption results in the continuing growth in greenhouse gases in the atmosphere.
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Carbon combines with other elements like oxygen and hydrogen to form carbohydrates and proteins (our food and energy sources) and nucleic acids (for example, DNA). Places on Earth that store carbon are called
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This note was uploaded on 04/02/2012 for the course ISS 310 taught by Professor Online during the Fall '05 term at Michigan State University.

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Climate Change - Moreover, most scientists also agree that...

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