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Global Warming as a Threat to Life on Earth

e greenhouse's interior. Scientists believe that greenhouse gases are responsible for keeping the earth's surface at an average temperature of about 25 degrees Celsius. The greenhouse effect maintains the earth's surface at a temperature that is 33 degrees Celsius warmer than it would otherwise be.

The greenhouse effect contributes to warm temperatures by helping balance the earth's physical energy budget: "There is a virtually perfect energetic balance between the quantity of electromagnetic energy that is incident to the earth and the amount that is ultimately dissipated back to outer space" (1:52). About 30 percent of incoming solar energy is reflected back into outer space by atmospheric clouds and aerosols or by the earth's surface. The remaining 70 percent is absorbed by atmospheric gases. Much of this absorbed solar radiation is reradiated into outer space as long-wave infrared radiation. Atmospheric gases and aerosols intercept some of these infrared rays in an ongoing exchange of energy: "The ground surface and lower atmosphere warm to a temperature such that the infrared energy they emit outward just balances the solar energy they absorb" (2:5). Greenhouse gases can remain in the earth's atmosphere for decades or even centuries. The theory of global warming suggests that, if these gases are allowed to accumulate indefinitely, a concentration of these elements will result in warmer temperatures throughout the earth.

Proponents of the theory of global warming point to several factors as evidence for their conclusions. One significant factor is warming trends. Climatologists have been reporting surface air temperature since 1880. Since these measurements began, the six warmest years on record have occurred in the 1980s. Overall, a net increase in the earth's surface air temperature of 0.5 degrees Celsius has occurred since 1850 (1:54). According to one university professor: "The probability of such a war...

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Global Warming as a Threat to Life on Earth. (1969, December 31). In LotsofEssays.com. Retrieved 00:51, March 29, 2024, from https://www.lotsofessays.com/viewpaper/1689411.html