Global warming is the long-term, cumulative effect that greenhouse gases, primarily carbon dioxide and methane, have on Earth's temperature when they build up in the atmosphere and trap the sun's heat. It's also a hotly debated topic. Some wonder if it's really happening and, if it's real, is it the fault of human actions, natural causes or both?
When we talk about global warming, we're not talking about how this summer's temperatures were hotter than last year's. Instead, we're talking about climate change, changes that happen to our environment, atmosphere and weather over time. Think decades, not seasons. The term global warming itself is a bit deceptive because it implies we should expect things to get hotter -- not necessarily stormier, drier and even, in some instances, colder. Climate change impacts the hydrology and biology of the planet -- everything, including winds, rains and temperature, is linked. Scientists have observed that the Earth's climate has a long history of variability, from the cold climes of the Ice Age to temperatures as hot as an Easy-Bake oven. These changes are sometimes noted over a few decades and sometimes stretch over thousands of years. What can we expect from a planet undergoing climate changes?
Scientists studying our climate have been able to observe and measure changes happening around us. For example, mountain glaciers are smaller now than they were 150 years ago, and in the last 100 years, the average global temperature has increased by roughly 1.4 degrees F (0.8 degrees C) [source: EPA]. Computer modeling allows scientists to predict what could happen if the climate pattern continues on its current course, projecting, for instance, that temperatures could rise an average of 2 to 11.5 degrees F (1.1 to 6.4 degrees C) by the end of the 21st century [source: EPA].
In this article, we'll look at 10 of the worst effects of climate change, including some immediate effects observed and some hypothesized through climate modeling.
10. Rising Sea Level
Earth's hotter temperature doesn't necessarily mean the Miami lifestyle is moving to the Arctic, but it does mean rising sea levels. How are hotter temperatures linked to rising waters? Hotter temperatures mean ice -- glaciers, sea ice and polar ice sheets -- is melting, increasing the amount of water in the world's seas and oceans.
Scientists are able to measure that melt water from Greenland's ice cap directly impacts people in the United States: The flow of the Colorado River has increased sixfold [source: Scientific American]. And scientists project that as the ice shelves on Greenland and Antarctica melt, sea levels could be more than 20 feet (6 meters) higher in 2100 than they are today [source: An Inconvenient Truth]. Such levels would submerge many of Indonesia's tropical islands and flood low-lying areas such as Miami, New York City's Lower Manhattan and Bangladesh.
9. Shrinking Glaciers
You don't need special equipment to see that glaciers around the world are shrinking. Tundra once covered with thick permafrost is melting with rising surface temperatures and is now coated with plant life.
In the span of a century, glaciers in Montana's Glacier National Park have deteriorated from 150 to just 35 [source: New York Times]. And the Himalayan glaciers that feed the Ganges River, which supplies drinking and irrigation water to 500 million people, are reportedly shrinking by 40 yards (37 meters) each year [source: The Washington Post].
8. Heat Waves
The deadly heat wave that swept across Europe in 2003, killing an estimated 35,000 people, could be the harbinger of an intense heat trend that scientists began tracking in the early 1900s [source: MSNBC].
Extreme heat waves are happening two to four times more often now, steadily rising over the last 50 to 100 years, and are projected to be 100 times more likely over the next 40 years [source: Global Development and Environment Institute, Tufts University]. Experts suggest continued heat waves may mean future increases in wildfires, heat-related illness and a general rise in the planet's mean temperature.
7. Storms and Floods
Experts use climate models to project the impact rising global temperatures will have on precipitation. However, no modeling 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].
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 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, 75 to 250 million Africans may experience water shortages, and the continent's agricultural output will decrease by 50 percent [source: BBC].
Depending on where you live, you may use bug repellant 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.
4. Economic Consequences
The costs associated with climate change rise along with the temperatures. Severe storms and floods combined with agricultural losses cause billions of dollars in damages, and money is needed to treat and control the spread of disease. Extreme weather can create extreme financial setbacks. For example, during the record-breaking hurricane year of 2005, Louisiana saw a 15 percent drop in income during the months following the storms, while property damage was estimated at $135 billion [source: Global Development and Environment Institute, Tufts University].
Economic considerations reach into nearly every facet of our lives. Consumers face rising food and energy costs along with increased insurance premiums for health and home. Governments suffer the consequences of diminished tourism and industrial profits, soaring energy, food and water demands, disaster cleanup and border tensions.
And ignoring the problem won't make it go away. A recent study conducted by the Global Development and Environment Institute at Tufts University suggests that inaction in the face of global warming crises could result in a $20 trillion price tag by 2100 [source: Global Development and Environment Institute, Tufts University].
3. Conflicts and War
Declining amounts of quality food, water and land may be leading to an increase in global security threats, conflict and war.
National security experts analyzing the current conflict in Sudan's Darfur region suggest that while global warming is not the sole cause of the crisis, its roots may be traced to the impact of climate change, specifically the reduction of available natural resources [source: Seattle Post-Intelligencer]. The violence in Darfur broke out during a time of drought, after two decades of little-to-no rain along with rising temperatures in the nearby Indian Ocean.
Scientists and military analysts alike are theorizing climate change and its consequences such as food and water instability pose threats for war and conflict, suggesting that violence and ecological crises are entangled. Countries suffering from water shortages and crop loss become vulnerable to security trouble, including regional instability, panic and aggression.
2. Loss of Biodiversity
Species loss and endangerment is rising along with global temperatures. As many as 30 percent of plant and animal species alive today risk extinction by 2050 if average temperatures rise more than 2 to 11.5 degrees F (1.1 to 6.4 degrees C) [sources: EPA, Scientific American]. Such extinctions will be due to loss of habitat through desertification, deforestation and ocean warming, as well as the inability to adapt to climate warming. Wildlife researchers have noted some of the more resilient species migrating to the poles, far north and far south to maintain their needed habitat; the red fox, for example, normally an inhabitant of North America, is now seen living in the Arctic.
Humans also aren't immune to the threat. Desertification and rising sea levels threaten human habitats. And when plants and animals are lost to climate change, human food, fuel and income are lost as well.
1. Destruction of Ecosystems
Changing climatic conditions and dramatic increases in carbon dioxide will put our ecosystems to the test, threatening supplies of fresh water, clean air, fuel and energy resources, food, medicine and other matters we depend upon not just for our lifestyles but for our survival.
Evidence shows effects of climate change on physical and biological systems, which means no part of the world is spared from the impact of changes to land, water and life. Scientists are already observing the bleaching and death of coral reefs due to warming ocean waters, as well as the migration of vulnerable plants and animals to alternate geographic ranges due to rising air and water temperatures and melting ice sheets.
Models based on varied temperature increases predict scenarios of devastating floods, drought, wildfires, ocean acidification and eventual collapse of functioning ecosystems worldwide, terrestrial and aquatic alike.
Forecasts of famine, war and death paint a dire picture of climate change on our planet. Scientists are researching the causes of these changes the vulnerability of Earth not to predict the end of days but rather to help us mitigate or reduce changes that may be caused by humans. If we know and understand the problems and take action through adaptation, the use of more energy-efficient and sustainable resources and the adoption of other green ways of living, we may be able to make some impact on the climate change process.
Lots More Information
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More Great Links
- "50 million on the run from deserts, warming?" MSNBC. 2007. http://www.msnbc.msn.com/id/19479607/
- Ackerman, Frank and Elizabeth Stanton. "Climate Change - the Costs of Inaction." Global Development and Environment Institute, Tufts University. 2006. http://ase.tufts.edu/gdae/Pubs/rp/Climate-CostsofInaction.pdf
- "Americans warned of global warming 'dust bowl'" Australian Broadcasting Corporation. 2007. http://www.abc.net.au/news/newsitems/200704/s1891479.htm
- "Arctic sea ice cover at record low." CNN. 2007. http://www.cnn.com/2007/TECH/science/09/11/arctic.ice.cover/index.html?iref=mpstoryview
- "Basic Information." Climate Change. U.S. Environmental Protection Agency. http://www.epa.gov/climatechange/basicinfo.html
- Biello, David. "State of the Science: Beyond the Worst Case Climate Change Scenario." Scientific American. 2007. http://www.sciam.com/article.cfm?id=state-of-the-science-beyond-the-worst-climate-change-case
- "Billions face climate change risk." BBC News. 2007. http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/6532323.stm
- "Changed climate, changed species." MSNBC. 2007. http://www.msnbc.msn.com/id/17861866/
- Charles, Dan. "Food & Climate: A Complicated but Optimistic View." NPR. 2007. http://www.npr.org/templates/story/story.php?storyId=15747012
- "Effects of Global Warming." National Geographic. http://science.nationalgeographic.com/science/environment/global-warming/gw-effects.html
- Eilperin, Juliet. "Military Sharpens Focus on Climate Change." The Washington Post. 2007. http://www.washingtonpost.com/wp-dyn/content/article/2007/04/14/AR2007041401209.html
- Faris, Stephan. "The Real Roots of Darfur." The Atlantic. 2007. http://www.theatlantic.com/doc/200704/darfur-climate
- "Feeling the heat: Climate change and biodiversity loss." Nature. 2004. http://www.nature.com/nature/links/040108/040108-1.html
- "Frequent Questions - Effects." Climate Change. U.S. Environmental Protection Agency. 2008. http://www.epa.gov/climatechange/fq/effects.html
- "Global Insecurity: Conflicts heat up." Seattle Post-Intelligencer. 2007. http://seattlepi.nwsource.com/opinion/320929_secured.html
- "Global Warming." The New York Times. http://topics.nytimes.com/top/news/science/topics/globalwarming/index.html
- "Global warming might hurt your heart." MSNBC. 2007. http://www.msnbc.msn.com/id/20607048/
- "Global Warming Would Foster Spread Of Dengue Fever Into Some Temperate Regions." ScienceDaily. 1998. http://www.sciencedaily.com/releases/1998/03/980310081157.htm
- "Impacts of Climate Change on Washington's Economy." Washington State Department of Ecology. http://www.ecy.wa.gov/climatechange/economic_impacts.htm
- Leahy, Stephen. "Grim Signs Mark Global Warming." Wired. 2004. http://www.wired.com/science/discoveries/news/2004/11/65654
- Loney, Jim. "Warming may reduce hurricanes hitting U.S." Reuters. 2008. http://www.reuters.com/article/environmentNews/idUSN2364087920080123?feedType=RSS&feedName=environmentNews&sp=true
- Moon, Ban Ki. "A Climate Culprit in Darfur." The Washington Post. 2007. http://www.washingtonpost.com/wp-dyn/content/article/2007/06/15/AR2007061501857.html
- Morell, Virginia. "Signs From Earth: Now What?" National Geographic. 2004. http://science.nationalgeographic.com/science/environment/global-warming/time-signs.html
- "NPAA El Niño Page." U.S. Department of Commerce National Oceanic and Atmospheric Administration. http://www.elnino.noaa.gov/
- "People & Ecosystems." World Resources Institute. http://www.wri.org/node/4048
- Perlman, David. "Shrinking glaciers evidence of global warming." The San Francisco Chronicle. 2004. http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2004/12/17/MNGARADH401.DTL
- "Scientific Facts on Climate Change 2007 Update." GreenFacts. 2007. http://www.greenfacts.org/en/climate-change-ar4/index.htm
- "Shrinking Glaciers." The New York Times. December 1, 2002. http://query.nytimes.com/gst/fullpage.html?res=9B00E7D91038F932A35751C1A9649C8B63
- Struck, Doug. "Climate Change Drives Disease To New Territory." The Washington Post. 2006. http://www.washingtonpost.com/wp-dyn/content/article/2006/05/04/AR2006050401931.html
- "The Basics of Global Warming." Sierra Club. http://www.sierraclub.org/energy/overview/
- "The Top 100 Effects of Global Warming." Center for American Progress. 2007. http://www.americanprogress.org/issues/2007/09/climate_100.html
- "Understanding climate change." USA Today. http://www.usatoday.com/weather/resources/climate/wclisci0.htm?loc=interstitialskip
- Vergano, Dan. "Study links more hurricanes, climate change." USA Today. 2007. http://www.usatoday.com/weather/hurricane/2007-07-29-more-hurricanes_N.htm
- Wax, Emily. "A Sacred River Endangered by Global Warming." The Washington Post. 2007. http://www.washingtonpost.com/wp-dyn/content/article/2007/06/16/AR2007061600461.html
- "What is an El Niño?" U.S. Department of Commerce National Oceanic and Atmospheric Administration. http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html
- "What is Global Warming?" An Inconvenient Truth. http://www.climatecrisis.net/thescience/