How Does Climate Change Affect America?
Climate change or global warming is a very real threat to the quality of life on Earth. While a definitive split exists between scientists on whether the Earth’s atmosphere has increased in temperature, studies have proven repeatedly average temperatures around the world have increased by at least 1.4 degrees Fahrenheit over the last 100 years. How America is impacted by climate change can be seen with changes in the weather and animal behavior.
Indicators of Climate Change
According to the United States Environmental Protection Agency, greenhouse gas emissions caused by humans have increased in the United States by 14 percent from 1990 - 2008. Carbon dioxide creates the highest amount of greenhouse gases with electricity generation the largest source of gas emissions. The evidence points to the fact of this increasing over the next few years as the population continues to grow, leading for the need of more electrical consumption.
Rising water temperatures affect our oceans, with sea surface temperatures the highest in the past three decades than at any other time since the late 1800s. Sea level has increased worldwide, averaging an inch a decade in the past few years. Acidity in the ocean has increased over the past 20 years, attributed to the level of carbon dioxide dissolved in the water. These changes in the oceans affect fish, coral and other marine life. Ultimately these changes to the ocean affect humans who make their living fishing, as well as food sources for mankind and other animals.
The Arctic shows the worst of the affects of climate change so far. Areas of the Arctic Ocean usually stay frozen for the entire year, but 2007, 2008 and 2009 had the lowest amount of ice coverage, with 2009 showing a 24 percent lower ice coverage than the 1979 - 2000 average.
United States glaciers have shrunk since the 1960s, and the rate of melting has increased. In fact, glaciers worldwide have lost more than 2,000 cubic miles of water since the 1960s. Lakes tend to not stay frozen for as long each winter and have a later freezing date than in previous decades.
Impact on the United States
In the United States, the average temperature has increased since 1901. In fact, seven of the top ten warmest years on record have been since 1990, with the last 10 five- year periods being the warmest on record. The north, west and Alaska have shown the highest increase in temperatures throughout the country.
Weather changes include an increase in heat waves since the 1970s, with a wider area in the United States now experiencing them. Although the worst heat waves occurred during the 1930s, average temperatures have increased. Over 6,000 deaths in the United States can be attributed to extreme heat within the past three decades.
Along with higher average temperatures come drought conditions. Droughts occur when there hasn't been sufficient rain for several months. From 2001-2009 about 30-60 percent of the United States' lower 48 land mass experienced drought conditions. However, data has not been collected long enough over the years to determine if drought conditions have increased over time.
The United States lower 48 states have seen an increase in precipitation, with an increase of 6 percent per century since 1901. Hawaii and parts of the southwest, have seen less precipitation during the same time. Heavy precipitation more often comes in single-day events than at any other time in recent years. Eight of the ten years with the highest amount of single-day precipitation have occurred since 1990. Even the annual levels of high precipitation have increased.
Severe weather such as hurricanes and tropical storms has grown stronger and more frequent due to the change in ocean water temperatures, while snow coverage has decreased since the 1970s.
There is a longer growing season, an average of two weeks longer since the beginning of the 20th Century. Plant survival rates have increased because of higher winter temperatures, and when leaves and flowers bloom and bird migration are all due to climate changes.