SCI/362 Environmental Issues and Ethics
August 5, 2013
Americansâ€™ health, security, and economic well-being are tied to climate and weather. In the last 2 years, the United States experienced 25 climate- and weather-related disasters exceeding $1 billionÂ ($115 billion total) in damages and claiming 1,019 lives. The public, businesses, resource managers, and policy leaders are increasingly asking for information to help them understand how and why climate conditions are changing and how they can prepare. ("Climate",Â 2013) Climate change is apparent now across our nation; and natural climate patterns, like El NiÃ±o, can ...view middle of the document...
Chlorofluorocarbons (CFCs), which were used extensively in refrigeration and for other industrial processes before their presence in the atmosphere was found to cause stratospheric ozone depletion. ("Global Climate Change",Â 2009).
OzoneÂ is a greenhouse gas, and is continually produced and destroyed in the atmosphere by chemical reactions. Human activities have increased the ozone concentration through the release of gases such as carbon monoxide, hydrocarbons, and nitrogen oxides.
Water vaporÂ is the most important and abundant greenhouse gas in the atmosphere. Human activities produce only a very small increase in water vapor through irrigation and combustion processes. ("Global Climate Change",Â 2009).
Sun and volcanic eruptions are just a minor factors, the Sunâ€™s energy output has followed its historical 11-year cycle of small ups and downs, but with no net increase.Â The two major volcanic eruptions of the past 30 years have had short-term cooling effects on climate, lasting 2 to 3 years. ("Global Climate Change",Â 2009).
Carbon release and uptake
Once carbon dioxide is emitted to the atmosphere, some of it is absorbed by the oceans and taken up by vegetation, although this storage may be temporary. ("Global Climate Change",Â 2009).
As the ocean absorbs carbon dioxide from the atmosphere, seawater is becoming less alkaline through a process generally referred to as ocean acidification. ("Global Climate Change",Â 2009).
Observed Climate Change
Global average temperature and sea level have increased, and precipitation patterns have changed. Temperatures are rising, the estimated change in the average temperature of Earthâ€™s surface is based on measurements from thousands of weather stations, ships, and buoys around the world, as well as from satellites. These measurements are independently compiled, analyzed, and processed by different research groups. There are a number of important steps in the data processing. These include identifying and adjusting for the effects of changes in the instruments used to measure temperature, the measurement times and locations, the local environment around the measuring site, and such factors as satellite orbital drift. For instance, the growth of cities can cause localized â€œurban heat islandâ€ effects.
Precipitation patterns are changing
Precipitation is not distributed evenly over the globe. Its average distribution is governed primarily by atmospheric circulation patterns, the availability of moisture, and surface terrain effects. The first two of these factors are influenced by temperature. Thus, human-caused changes in temperature are expected to alter precipitation patterns.
Sea level is rising
There are two principal ways in which global warming causes sea level to rise. First, ocean water expands as it warms, and therefore takes up more space. Warming has been observed in each of the worldâ€™s major ocean basins, and has been...