Global Warming –Is it a fact or a fiction? Climate change is the single biggest environmental and humanitarian crisis of our time. The Earth's atmosphere is overloaded with heat-trapping carbon dioxide, which threatens large-scale disruptions in climate with disastrous consequences. We must act now to spur the adoption of cleaner energy sources at home and abroad.

The evidence for rapid climate change is compelling: -Global sea level rose about 17 centimeters in the last century. The rate in the last decade, however, is nearly double that of the last century. -All three major global surface temperature reconstructions show that Earth has warmed since 1880. Most of this warming has occurred since the 1970s, with the 20 warmest years having occurred since 1981 and with all 10 of the warmest years occurring in the past 12 years. Even though the 2000s witnessed a solar output decline resulting in an unusually deep solar minimum in 2007-2009, surface temperatures continue to increase. -The oceans have absorbed much of this increased heat, with the top 700 meters of ocean showing warming of 0.302 degrees Fahrenheit since 1969. - Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades. -Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa. Average temperature is approximately halfway between the averages of day maximum and night minimum temperatures. In January, lowest temperatures occur over the northern continents, Siberia and northern Canada, where the excess of radiation loss to radiation receipt is greatest. The North Pacific and North Atlantic are warm and the prevailing westerlies carry warmth to the adjacent land, particularly into Europe. Eastern coastal areas, on the other hand, have prevailing winds from the cold continental interiors and are much colder than at corresponding latitudes on western coasts. The warmest areas are the land masses of the southern hemisphere, particularly

South Africa and Australia. In July, the northern continents are strongly heated. The hottest temperatures are the desert areas of the Sahara, Arabia, northwest India and California with average temperatures well in excess of 30°C. Whilst equatorial regions receive the most solar radiation, they are somewhat cooler than the deserts of the sub-tropical, since considerable energy is consumed in evaporating the abundant moisture that precipitates there.

Global yearly average temperatures are shown in the figure below.

Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth. This is a type of greenhouse effect. Earth's climate is mostly influenced by the first 6 miles or so of the atmosphere which contains most of the matter making up the atmosphere. This is really a very thin layer if you think about it. In the book The End of Nature, author Bill McKibbin tells of walking three miles to from his cabin in the Adirondack's to buy food. Afterwards, he realized that on this short journey he had traveled a distance equal to that of the layer of the atmosphere where almost all the action of our climate is contained. In fact, if you were to view Earth from space, the principle part of the atmosphere would only be about as thick as the skin on an onion! Realizing this makes it more plausible to suppose that human beings can change the climate. A look at the amount of greenhouse gases we are spewing into the atmosphere, makes it even more plausible. The most significant greenhouse gas is actually water vapor, not something produced directly by humankind in significant amounts. However, even slight increases in atmospheric levels of carbon dioxide (CO2) can cause a substantial increase in temperature. Why is this? There are two reasons: First, although the concentrations of these gases are not nearly as large as that of oxygen and nitrogen (the main constituents of the atmosphere), neither oxygen or nitrogen are greenhouse gases. This is because neither has more than two atoms per molecule, and so they lack the internal vibrational modes that molecules with more than two atoms have. Both water and CO2, for example, have these "internal vibrational modes", and these vibrational modes can absorb and reradiate infrared radiation, which causes the greenhouse effect. Secondly, CO2 tends to remain in the atmosphere for a very long time (time scales in the hundreds of years). Water vapor, on the other hand, can easily condense or evaporate, depending on local conditions. Water vapor levels therefore tend to adjust quickly to the prevailing conditions, such that the energy flows from the Sun and re-radiation from the Earth achieve a balance. CO2 tends to remain fairly constant and therefore behave as a controlling factor, rather than a reacting factor. More CO2 means that the balance occurs at higher temperatures and water vapor levels. In reality, we will need to work on all fronts - 10% here, 5% here, etc, and work to phase in new technologies, such as hydrogen technology, as quickly as possible. To satisfy the Kyoto protocol, developed countries would be required to cut back their emissions by a total of 5.2 % between 2008 and 2012 from 1990 levels. Specifically, the US would have to reduce its presently projected 2010 annual emissions by 400 million tons of CO2 . One should keep in mind though, that even Kyoto would only go a little ways towards solving the problem. In reality, much more needs to be done. The most promising sector for near term reductions is widely thought to be coal-fired electricity. Wind power, for example, can make substantial cuts in these emissions in the near term, as can energy efficiency, and also the increased use of high efficiency natural gas generation. The potential impact of efficiency should not be underestimated: A 1991 report to Congress by the U.S. National Academy of Sciences, Policy Implications of Greenhouse Warming, found that the U.S. could reduce current emissions by 50 percent at zero cost to the economy as a result of full use of cost-effective efficiency improvements.