Extreme weather

Global warming raises serious concerns over its potential to cause damage to people, property, and the environment as a result of extreme weather events, such as severe drought and storms. Today, scientists, such as Dr. Christopher Landsea at NOAA, are trying to understand just how much impact global warming may have on the occurrence and frequency of drought, hurricanes, and tornadoes. It still remains difficult to assess because global warming will have different impacts on different areas of the Earth. Although they cannot predict exactly where hurricanes or other severe storms will occur in the future, they are fairly certain that as the atmosphere continues to warm under the influence of global warming, it will cause an increase in heat waves. Because warmer air can hold more moisture, it will change the hydrologic cycle, which will alter flooding and drought patterns. There is a great concern that increasing ocean temperatures will also increase the likelihood of tropical cyclones—or hurricanes.

The World Meteorological Organization (WMO) has warned that extreme weather events, such as drought, hurricanes, and heavy rainfall, may very likely increase because of global warming. They have noted that episodes of extreme weather have been on the rise in recent years and that the rate of events is increasing. In fact, in a report released in 2002, they concluded that the severe drought Australia suffered that year was due principally to human-induced global warming.

There are not many forces in nature that can compare to the destructive capability of a hurricane. These storms can have winds blow for long periods of time at 155 miles per hour (249 km/hr) or higher. Not only is the wind destructive, but also the rainfall and storm surges can cause significant damage and loss of life.

Hurricane Katrina, which formed August 23, 2005, and dissipated August 30, 2005, affecting the Bahamas, South Florida, Cuba, Louisiana, Mississippi, Alabama, and the Florida Panhandle, was the deadliest hurricane in the history of the United States, killing more than 1,800 people and destroying more than 200,000 homes. It created more than 900,000 evacuees and was the costliest hurricane in U.S. history, with more than $75 billion in estimated damages. Today, only about 40 percent of New Orleans pre-Katrina residents have returned to the city. A hurricane, or tropical cyclone, forms over tropical waters—between latitudes 8° and 20° in areas of high humidity and light winds, where the sea surface is warm. Typically, temperatures must be 80°F (26.5°C) or warmer for a hurricane to start. This is why global warming and the heating of the ocean are such concerns.

The most typical time for a hurricane to form is in the summer and early fall of the tropical North Atlantic and North Pacific Oceans, making the Northern Hemisphere's hurricane season run June through November.

0 0

Post a comment