Global Warming: background
The Union of Concerned Scientists, a group of over two thousand scientists, has concluded that global warming is beyond dispute, and already changing our climate.Posted Mar 27, 2009
The last 30 years has seen the warmest surface temperatures in recorded history.
Scientists are documenting the rapid melting of glaciers. Snow cover is melting much earlier in the year. Ocean temperatures have warmed, sea levels have risen almost one foot, and the patterns of deep sea currents are shifting. Average surface temperatures in Antarctica have risen two degrees Fahrenheit since 1950. Permafrost in Alaska is thawing, threatening the oil pipeline, buckling highways, and causing other havoc. The ten hottest years in recorded history have all taken place since 1980.
Scientists have concluded that human activity, primarily the burning of fossil fuels, is the major driving factor in global warming.
For centuries, the production and absorption of carbon dioxide and other greenhouse gases was in balance. Humans and animals produce these gases by burning food in our bodies with the oxygen we breathe. Trees and other plants reverse the process with photosynthesis, turning carbon dioxide back into oxygen and vegetation which is food for us and the animals. The oceans help keep the concentrations in the atmosphere stable by absorbing small excesses in carbon dioxide.
But in the last century, human activity has overwhelmed the earth’s natural feedback mechanism. The burning of wood and all sorts of fuels, including cow dung and whale oil greatly increased the amount of carbon dioxide produced. At the same time, clear-cutting of forests reduced the earth’s capacity to absorb it. The industrial revolution and the discovery and use of fossil fuels has enormously exacerbated the problem. The automobile has been the straw that broke the camel’s back. For every gallon of gasoline burned, 26 pounds of carbon dioxide is put into the air. There is just no way the plants and oceans can absorb the billions of tons of greenhouse gases produced by automobiles each year. More billions of tons are produced by power plants generating electricity.
The end result has been an increase of more than 30% in the concentration of carbon dioxide in the atmosphere. If we don’t change our ways, it is forecast to triple by 2100.