Storms and Floods

Experts use climate models to project the impact rising global temperatures will have on precipitation. However, no modelling is needed to see that severe storms are happening more frequently: In just 30 years the occurrence of the strongest hurricanes -- categories 4 and 5 -- has nearly doubled [source: An Inconvenient Truth].

Warm waters give hurricanes their strength, and scientists are correlating the increase in ocean and atmospheric temperatures to the rate of violent storms. During the last few years, both the United States and Britain have experienced extreme storms and flooding, costing lives and billions of dollars in damages. Between 1905 and 2005 the frequency of hurricanes has been on a steady ascent. From 1905 to 1930, there were an average of 3.5 hurricanes per year; 5.1 between 1931 and 1994; and 8.4 between 1995 and 2005 [source: USA Today]. In 2005, a record number of tropical storms developed, and in 2007, the worst flooding in 60 years hit Britain [sources: Reuters, Center for American Progress].

Warmer waters increase the likelihood of violent storms. Hurricane Dolly swept over the Texas-Mexico border in July 2008.

Drought

While some parts of the world may find themselves deluged by increasing storms and rising waters, other areas may find themselves suffering from drought. As the climate warms, experts estimate drought conditions may increase by at least 66 percent [source: Scientific American]. An increase in drought conditions leads quickly to a shrinking water supply and a decrease in quality of agricultural conditions. This puts global food production and supply in danger and leaves populations at risk for starvation.

Today, India, Pakistan and sub-Saharan Africa already experience droughts, and experts predict precipitation could continue to dwindle in the coming decades. Estimates paint a dire picture. The Intergovernmental Panel on Climate Change suggests that by 2020, from 75 to 250 million Africans may experience water shortages, and the continent's agricultural output will decrease by 50 percent [source: BBC].

Worldwide droughts, like that in a village northeast of Nairobi, expose rural communities to food shortages.

Disease

Depending on where you live, you may use bug repellent to protect against West Nile virus or Lyme disease. But when was the last time you considered your risk of contracting dengue fever?

Warmer temperatures along with associated floods and droughts are encouraging worldwide health threats by creating an environment where mosquitoes, ticks, mice and other disease-carrying creatures thrive. The World Health Organization (WHO) reports that outbreaks of new or resurgent diseases are on the rise and in more disparate countries than ever before, including tropical illnesses in once cold climates -- such as mosquitoes infecting Canadians with West Nile virus.

While more than 150,000 people die from climate change-related sickness each year, everything from heat-related heart and respiratory problems to malaria are on the rise [source: The Washington Post]. Cases of allergies and asthma are also increasing. How is hay fever related to global warming? Global warming fosters increased smog -- which is linked to mounting instances of asthma attacks -- and also advances weed growth, a bane for allergy sufferers.

A field sample of mosquitoes that could carry West Nile virus pictured in California.

Дата добавления: 2015-10-26