Volcanoes:
Volcanic activity is responsible for both the warming and cooling of Earth. When people first think of volcanoes, images of black smoke and bright red lava flash through their minds. But volcanoes are most effective at creating climate change when they expel dust and gases into the atmosphere. While the image is not as glamorous as the movie industry would have people believe, such volcanic activity can cause global cooling and global warming. (This is some talented gas!)
The dust that volcanoes emit enters the atmosphere and can remain there for years, causing dramatic changes in climate. Volcanic dust, due to huge eruptions, cools the planet by first reducing the temperature in the lower atmosphere by preventing the heat from the sun from getting into the stratosphere (Sutherland, 1995). Scientists know that "volcanic eruptions can cough up enough material… to block sunlight and cool the planet temporarily" (Oliwenstein, 1992). Thick, black clouds of dust and soot can cast a shadow over Earth, keeping the vital rays from the sun away from the land and water below. Temporarily, this is nothing more than a cold, cloudy day. But the dust could "maintain cool conditions by blocking sunlight" for an extended period of time, keeping the sun’s warmth from penetrating Earth’s atmosphere (Monastersky, 1997). Often considered a cause of ice ages, volcanic gases can cause dramatic climate changes by creating perpetual night, endless darkness, and devastating cold.
Gases expelled from eruptions can have another, very different, very damaging effect on Earth as well. In the twenty-first century, carmakers, hair-spray manufacturers, and Greenpeace members are very concerned with "Greenhouse Gases." Carbon dioxide and other harmful compounds are slowly raising the temperature on planet Earth. For billions of years, volcanoes have contributed to the disruption of our delicate atmosphere, depleting ozone layers and often causing "holes" in the ozone (Sutherland, 1995). When a hole develops in the atmosphere, dangerous ultra-violet rays are not filtered through dense layers of ozone before hitting the planet. Instead, excessive amounts of radiation pass freely to the ground, heating the earth. It is known that "volcanoes pump out greenhouse gases regularly" and that "greenhouse gases raise ambient temperatures" (Sutherland, 1995). Another way dust from volcanoes makes the Earth hotter is, ironically, the same way it made the Earth colder: by preventing the transmission of warmth through the atmosphere. The Earth emits heat and these rays need to escape the planet to maintain tranquil temperatures. When volcanic dust blocks sunlight from entering Earth, it also keeps Earth’s heat in, trapping it and forcing global temperatures to rise. As previously stated: THIS IS SOME MULTI - TALENTED GAS! |
