Global Warming & Extreme Weather

Extreme Weather

An old saying reminds us that “the only thing you cannot change is the weather.” In fact, humans are changing the weather by contributing to the phenomenon of  global warming. Despite what the term “global warming” may suggest regarding global weather, the effects of global warming will actually be more frequent extreme weather rather than solely increasing temperatures. In fact, there are several types of weather that will reach more extremes in frequency and intensity as  global temperatures steadily increase. 

Hurricanes

Several researchers have suggested that warmer global temperatures will lead to hurricanes that are more frequent and more destructive in nature. While there is skepticism in the scientific community as to the degree and timing of these changes, there is a wide consensus that these changes are indeed occurring. 

A hurricane is a tropical storm that has sustained wind speeds of over 74 miles per hour. Hurricanes are ranked in severity from categories one through five, with five being the most severe. Hurricanes draw their power from the heat of the underlying ocean. So, it follows that higher global (ocean) temperatures would lead to stronger and more frequent hurricanes. Although the specific cause of warmer ocean temperatures is still being debated, the IPCC (the Intergovernmental Panel on Climate Change) stated in 2007 that it is “more likely than not” that human activities are to blame for this increase in hurricane frequency and intensity. 

Since 1995 hurricanes have been more numerous and more intense than average, except for 1997 and 2006. Both these years were El Nino years, which tend to decrease hurricane activity below average.   

Wildfires

Increasing frequency and intensity of wildfires is also expected. Less rainfall locally allows trees and underbrush to become exceedingly dry and better fuel for fires. 

Many spruce bark beetles (and other burrowing beetles that infest trees) are killed off during harsh winter temperatures in northern and alpine regions of the world. Warmer winter temperatures have made for large populations of beetles to forage on trees, killing large stands of trees at a time. These dead trees are flammable and fires in these regions quickly burn out of control. Snowmelt is also occurring earlier during the year, leaving things much drier in the spring and summertime. 

Wildfires are a significant source of carbon emissions. Since wildfire intensity has increased, it has been estimated that smoke from wildfires places nearly 40% equivalent of carbon emissions put in the atmosphere as that of the carbon emissions created by burning fossil fuels. This leads to more carbon dioxide in the air, which leads to more global warming and, in turn, a greater number of wildfires. It also significantly decreases the quality of the air people breathe and can lead to a loss of human life. 

Wildfires account for a significant amount of property damage each year, which is increasing annually. Since 1986 the annual number of wildfires is six times greater than the average before 1986. Additionally, the ‘wildfire season’ which is thought of as being during the summertime has now become longer. In the past few years alone, wildfires have burned millions of acres, destroying natural resources and leaving thousands of people without homes. 

Droughts

Higher  global temperatures lead to a greater rate of evaporation in lakes, rivers, steams and other bodies of water. In areas where these bodies of water are temporary, the period of time they are available is decreasing. Rain clouds are formed partially by evaporation from water sources. In dry climates, water from soil is evaporated and forms rain clouds. Dryer soils which have no water to lose to evaporation will lead to a reduction in rain clouds, which will make for even dryer soils.  

Many organisms are dependent, at least seasonally, on standing water. Droughts from higher global temperatures are expected to impact the interior portions of large continents. In the United States, this is equivalent to the greatest grain-growing and cattle-grazing region of the country. Lack of water can lead to total crop failure, and starvation in areas of the world that depend on crop production for sustenance.

Heat-waves

As average global temperatures rise, so do the maximum temperatures  reached in the summertime. The summer of 2003 was the warmest on record, killing at least 27,000 people worldwide. While this summer was an extreme example, increased global temperatures have doubled the chance that a fatal heat wave will occur. Models predict this to become one hundred fold within the next 30 years. 

Flooding and Torrential Rainfall

Higher ocean temperatures lead to higher evaporation and the formation of a greater number of storm clouds. These clouds can become so laden with water that the ensuing rain is torrential. 

An increased frequency of El Niño events has also contributed to higher rainfall potential. El Niños are periods of higher-than-normal temperatures in the eastern Pacific ocean. This leads to higher rainfall in the southern United States and Peru, but lower than average rainfall in the northwestern United States, parts of Brazil, Asia, Africa and most of Australia. Increased global temperatures will lead to El Niños that are longer and more intense, which will lead to stronger droughts and flooding to the areas El Niños affect the most. 

It is clear that the effects of global warming are more than simply increased global temperatures. The extreme weather each individual experiences will depend on the area of the world in which he or she lives and are becoming more inevitable each year.

Comment on "Global Warming & Extreme Weather"