Preparing for the Potential Impacts of Climate Change in the United States
This is not a matter of Chicken Little telling us the sky is falling.� The scientific evidence is telling us we have a problem, a serious problem.
����������� ����������� -U.S. Department of Energy, report 2, 2 April 1979. (Rodes and Odell 120)��������
Climate change, better known as global warming or the greenhouse effect, is both a natural and man-made phenomenon (Gore 92).� Climate change is simply a shift in average weather. This phenomenon has the potential of causing impacts on the various ecosystems in the various regions of the United States.��
There is a naturally occurring greenhouse effect on Earth.� Without it, there would not be any life on the planet.� Without the greenhouse effect on the planet, the average temperature would be 60 oC colder then what it is now (Michaels and Balling 25; British Columbia Internet; Spencer 27).� Also, there would be no life on the planet without the natural greenhouse effect (British Columbia Internet; Jardine et. al Internet).
�There are gases, greenhouse gases, in the atmosphere that trap long wavelength solar heat, which includes water vapor, carbon dioxide, methane, and nitrous oxide (Aguado and Burt 453; Zwiers and Weaver 2081).�� However, due to human activities, fingerprints (Kerr 1040), concentration of greenhouse gases has been increasing exponentially.�� But there are natural sources that cause the concentration of carbon dioxide to increase, such as volcanoes and photosynthesis.� All of the greenhouse gases have different life spans (British Columbia Internet).� Also all of these gases have different global warming potentials (GWP).� The three greenhouse gases that have the highest GWPs are carbon dioxide, methane, and nitrous oxide (Reid 131, 133).�
For an example, carbon dioxide, a trace gas (Spencer 25), has increased 30 percent since 1860, from 280 to 360 parts per million (ppm), where the main cause for this increase is due to fossil fuel combustion (IPCCa 18; Michaels and Balling 31; Rauber 36). The oceans, which have the ability to absorb the carbon dioxide out of the atmosphere (NASA Internet), have 58x more CO2 than the atmosphere does (Emiliani 256).� Plants and soils have the ability to absorb CO2 from the atmosphere (Jardine et. al Internet).
The concentration of carbon dioxide is predicted to increase to 560 ppm during this century (Gelbpspan 25). Due to this increase in carbon dioxide, it has been predicted that the average global temperature will increase 5 to 7 more degrees because fluctuations of carbon dioxide and temperature mirror each other.� However, the increase of the concentration does not hurt the animals or plants on the planet, and the amount of carbon dioxide, in terms of percentage, is only 0.03%.�
����������� Methane is a naturally occurring greenhouse gas, but its concentration is increasing from 280 ppm to 1720 ppm due to human activities, such as fossil fuel combustion, landfills, fertilizers and biomass burning (IPCCa 19, 21; British Columbia Internet; Switzer and Bryner 221).� Methane has 20x to 30x more heat-trapping power than carbon dioxide does (Revkin 95).� It also contributes 20% of the change in the greenhouse effect (Michaels and Balling 31).��
Also, the concentration of nitrous oxide (N2O) has increased by 8% since the Industrial Revolution, from 275 ppm to 312 ppm (IPCCa 19, 22; British Columbia Internet; Lemonick 25).� Nitrous oxide mainly comes from fossil fuel combustion (British Columbia Internet) and bacteria that live in the soils and water (Tolba 26).
Water vapor is the most important of the greenhouse gases; it accounts for 95% of the earth's natural greenhouse effect. � It has been predicted that the amount of water vapor will increase as the average surface temperature increases (Spencer 29).�
All of the states in the United States are experiencing changes in the average temperature and amount of precipitation.� Mainly, all of the states are facing wetter conditions than dry conditions.� Also, they could experience more changes in average temperature and the amount of precipitation in each of the four seasons. Overall, the states could experience increases in average temperature and precipitation in each of the four seasons.
Since 1880, the average global temperature has increased 1.0 oF.�� Due to this prediction, global warming could cause dramatic changes in the climate around the world, which affects the various ecosystems in the United States, ranging from aquatic to forests.������
Coastal Ecosystems
����������� Global warming can have major impacts on coastal ecosystems.� These impacts include erosion of beaches, increased flooding in coastal areas, increased salinity in marshes. These could affect ship channels, ports, and other major forms of waterway transportation (Neumann et. al 3).� The most likely place to experience climate change impacts is the Gulf Coast and the Atlantic coast, because they are low in elevation (Neumann et. al 4; National 108).� Due to these impacts, some of the species in coastal areas could be become endangered (Neumann et. al 7).�
����������� The Intergovernmental Panel on Climate Change (IPCC) concluded that sea-ice in the Artic Ocean and around Antarctica has been melting due to the increase of surface temperature around the globe.� This melting of sea-ice could cause the seas to rise to 65 cm high (Neumann et. al 8-9; Tolba 29; Hvidberg 551).� On the mid-Atlantic coast, the relative sea level has risen 0.3 to 0.4 meters per century.� On the other hand, the West coast has been seeing rising and falling trends (Neumann et. al 10-11).� Due to this possible sea level, some of the state of Florida would be underwater.
����������� �� Due to the possible effects of global warming, strong storms, such as hurricanes, could become stronger and more disastrous (Neumann et. al 16).� These powerful storms can create intense storm surges and floods, such as a 100-year flood (IPCCb 300).� These floods can cause erosion along the various coastlines of the United States, and it has been determined that the majority of the U.S.'s beaches are in the process of eroding away.� According to one source, the beaches of on the east coast could erode away within 25 years (Rauber 41).� For an example, Maryland has lost some of its wetlands due to erosion (Titus Internet).
�Also the storms can cause damage or shut down the major ports on each coast of the country.� An area that would be threaten each time that a storm develops in the Gulf of Mexico is Galveston, Texas because it has sandy barrier beaches (Titus Internet).� Due to these sandy barrier beaches, Galveston could be underwater each time that an intense storm hits it (Revkin 131).�
����������� There are ways to stop the sea level from rising too far into inland; one way is by building levees or by raising the city.�� In this way, even though the sea level does rise, it will not affect the buildings in the city (IPCCb 302-303).�
����������� The coastal ecosystems of the United States could be affected in other ways too.� The organism in these coastal ecosystems could also be affected by global warming.� For example, lobster populations in the Northeast region might migrate northward due to the� possibility that ocean water will become too warm for them (National 45).�� The coastal habitat could be reduced due to climate change. As a result, migratory birds cannot live in the Northeast (National 45).�� Also global warming can cause additional stresses on the salmon in the Pacific Northwest.� There is the possibility that stream flows could change and could cause the habitat to be unfavorable to the salmon (National 70-71).� In Alaska, the number of important fish could decline due to climate fluctuations (National 78).�
Forests
����������� There has been an increasing concern on how could global warming have the potential of affecting the U.S's various forest ecosystems (Sun et. al 367).� If global warming does occur, it could cause some problems for the different types of forests in the United States.� Global warming can cause both positive and negative effects to the different forest areas in the United States.� The forest areas have three important functions: 1) regulate the Earth's climate; 2) provide homes for the Earth?s animals and plants; and 3) they are part of a major industry (Jardine Internet).
����������� The northern Boreal Forests, better known as the taiga, could experience 50 to 90% in disappearance due to the elevating levels of carbon dioxide in the atmosphere (Jardine Internet).� This could result in endangering species of plants and animals that are dependant on the northern boreal forests.��
����������� The frequency of fires could increase due to the possible change in climate. Forest fires are the driving force in boreal forests (Jardine Internet; National 77).�� Fires determine what species of plants can live there.� For instance, when the frequency of forest fires every 100 years, fir and spruce trees dominate the boreal forest area.� If the frequency ranges between 50 and 100 years, then it is pine tree.� Then, if it is less than 50 years, the trees that tend to dominate are aspen and birch (Jardine Internet).�
����������� On the positive side, carbon dioxide can cause plants in boreal forests to grow faster.� In lab experiments, seedlings have shown a 20-120% growth when there is more carbon dioxide in its environment (Jardine Internet; Malcolm and Pitelka 17).�� But if there is too much carbon dioxide, then it could the plant to reduce its growth and reducephotosynthesis (Jardine Internet; Grace and Rayment 819; Alward et. al 229).� Increased concentrations of carbon dioxide canmake plants become drought-resistant (Jardine Internet).
����������� Climate change could have effects on C3, C4, and CAM plants.� C3 plants are plants that do not have efficient photosynthesis, whereas, C4 plants are ones that have an efficient method of photosynthesis (Alward et. al 229).�� If the concentration of carbon dioxide does increase, the growth will increase by 34% and 14% in C3 and C4 plants, respectively.� Also if the temperature increases by 3 oC, the growth for C3 plants was estimated to be about 56% (Krauchi 32).�� Other possible effects of global warming on C3 and C4 plants include an increase in photosynthesis, water efficiency, and leaf area.� There are some possible decreases, too, such as in leaf conductance and drought stress sensitively (Krauchi 33).�
����������� ���� Other types of forests in the United States could also experience effects of global warming.� Some forests have a possibility of moving northward to suit them better; sugar maple trees in the Northeast could migrate to Canada (National 45).
Another example is the temperate mixed forests located in the Southeast region have the possibility of moving northward and be replaced by grasslands (Malcolm and Pitelka 10).� Some other forests could either expand or be reduced.� For instance, the conifer forests could either reduced to only 6.5% or expand to cover 22.1% of the United States (Malcolm and Pitelka 10).�� Also, global climate change has the potential of affecting the growth and the life span of the individual trees in Southeast region (Harcombe Internet).�
����������� A forest's productivity could be affected due to global warming (National 114).� According to a forest process model (PnET-II), the forest areas in the southeast could lose their productivity from 11% in 2040 to 8% in 2100.�� Other areas could increase their productivity.� For instance, pine hardwood forests could increase productivity 22% by 2040 and 25% by 2100 (National 50).�� An increase of productivity could mean that timber production will increase (Malcolm and Pitelka 15).� Another example of a possible increase in primary production and carbon storage is in the arctic tundra (Grogan and Chapin III 512).
Another effect of global warming is that the biodiversity of forests in the United States could change.� According to the Hadley and Canadian models, the dominant types of forest that could be seen in the United States by 2100 are Oak-Pine and Oak-Hickory (National 117).� The significance of this possible climatic change impact is that forest types will change in the different regions of the United States.
����������� In terms of tree pests, insects, global warming could cause an increase in frequency of pests.� Cottonwood leaf rust could migrate to warm climates and threaten cottonwood trees.��Bark beetles could have the ability to increase the frequency of ecosystem disturbances (Krauchi 37).
Water Resources
����������� Global warming has the potential of impacting the United States water resources.� The amount of water available, affect aquatic ecosystems, and water quality in various river systems in each of the regions of the country could be affected.�
����������� In major river basins, the amount of runoff that occurs varies month and month and correspond the amount of precipitation during that particular month (Wolock and McCabe 1432-1344).� The amount of water available various river systems could be affected.� An example is that the water supply in Colorado River system could be diminished due to the impacts of climate change (Gleick and Chalecki 1430).� According to a study, if the amount of precipitation reduces by 10%, then the amount of runoff in the Colorado River would reduce by 40%.� In another study, if there is a 10% change in precipitation would lead to a 20% change in runoff (Gleick and Chalecki 1431).� However, when the runoff increases so do the frequency and the size of floods increase too (Gleick and Chalecki 1433).�� In the Sacramento-San Joaquin River basin, increase in temperatures could affect the river system.�� For instance, increase in temperature could cause the snowmelt season to shorten and a possible decrease in runoff in the late spring and summer months (Gleick and Chalecki 1435). In the Pacific Northwest mountains, an increase in the amount of precipitation rather than snow, in terms of rain, could mean an increase of runoff in the spring and depleted water resources in the summer months (Leung and Wigmosta 1463, 1467-1468).�
����������� Global warming has a possibility of affecting the biodiversity in terrestrial aquatic ecosystems.�� Some species of organisms are quite sensitive to temperature change.� This could cause cold-water species to move northward if the temperatures in their habitat increase or cause an extinction of cold-water fish (Meyer et. al 1375).� This would cause exotic species and warm-water species to dominate the waters where cold-water species inhabited (Meyer et. al 1379).� For instance, in the Rocky Mountains and the Southeastern portion of the United States, the number of cold-water species could be reduced if the temperatures increase (Meyer et. al 1376, 1377).��
����������� Climatic change can have an impact on water quality of different aquatic systems.� It can cause dissolved oxygen levels to be reduced in river basins.�� Low dissolved oxygen level exhibit extreme environmental conditions.� When conditions are dry, low dissolved oxygen levels are usually present (Cruise et. al 1540).� In terms of nitrate levels, when the environmental conditions are extreme, the nitrate levels are usually high.� High nitrate levels can have negative impacts on water quality and aquatic ecosystem health (Cruise et. al 1540-1542).�� Also in extreme conditions, the pH of the water can become more acidic (Cruise et. al 1542).� When the water levels are decreased, there is a possible increase in salinity in aquatic systems (National 99).
����������� A greenhouse warming can have serious effects on water demands and whether or not the United States can meet those demands (Frederick and Schwarz 1583).� Irrigation accounts for 81% of the United States demand for water.� In hot and dry conditions, the demand of water for irrigation increases (Frederick and Schwarz 1570).� If the average annual precipitation reduces by 25%, then the demand of water for irrigation also increases (Eheart et. al 1365). This could cause a great demand and stress on the water supply in the United States (National 98). However, if the amount of precipitation in the United States increases by 5-10%, a relative increase of runoff would also increase (National 98).�
����������� There is great uncertainty on whether or not these potential impacts of global� warming will occur in the United States.� It is difficult to determine these global warming effects will occur on forest, coastal, or terrestrial aquatic ecosystems.�� The climate as well as these ecosystems are extremely complex.�
���������������������� ����������������������� Works Cited
Aguado, Edward and Burt, James E.� Climate Changes: Past and Future.�� Understanding
����������� Weather and Climate.� 2nd Edition.�� New Jersey: Prentice Hall, Inc.� 2001.� 434-464.
Alward, Richard D.; Detling, James K. and Milchunus, Daniel.� 1999.� Grassland vegetation
��������������� Changes and Nocturnal global warming. Science.� 283: 229-231.
Cruise, J.F; Limaye, A.S. and Al-Abred, N.�� 1999.� Assessment of impacts of climate change on
water quality in the Southeastern United States.� Journal of the American Water Resources Association.� 35: 1539-1550.
Eheart, J.W; Wildermuth, A.J.; and Herricks, E.E.� 1999.� The effects of climate change and
����������� irrigation on criterion low streamflows used for determining total maximum daily loads.
����������� Journal of the American Water Resources Association.� 35: 1365-1372.
Emiliani, Cesare.� The Atmosphere.�� Planet Earth: Cosmology, Geology, and the Evolution
of Life and Environment.� New York, New York: Press Syndicate of the University of Cambridge.� 1992.� 254-286.
Frederick, K.D. and Schwarz, G.E.� 1999. Socioeconomic impacts of climate change on U.S.
����������� water supplies.� Journal of the American Water Resources Association.� 35:1583-1582.��
Gelbspan, Ross.� Reality Check.� E: The Environmental Magazine.� Vol. 11, no. 5.� 2000.� 24-26.
Gleick, Peter H. and Chalecki, Elizabeth L.� 1999.� The impacts of climatic changes for water
����������� resources of the Colorado and Sacamento-San Joaquin River Basins.� Journal of the
����������� American Water Resources Association.� 35: 1429-1441.
Global Climate Change: A Science Update.�� British Columbia Ministry of Environment, Lands,
����������� and Parks.� November 1995.� Internet.� Available online.� Accessed on: April 5, 2001.
����������� http://www.elp.gov.bc.ca/epd/epdpa/ar/climate/gccasu.html
Gore, Al.� Buddha's Breath.� Earth in the Balance: Ecology and the Human Spirit.� New York,
����������� New York: Penguin Group. 1993.� 81-98.��
Grace, John and Rayment, Mark.� 2000.� Respiration in the balance.� Nature.� 404: 819-820.
Grogan, P. and Chaplin III, F.S.�� 2000.�� Initial effects of experimental warming on above- and
����������� below ground components of net ecosystem CO2 exchange in arctic tundra.�
����������� Oecologia.� 125: 512-520.
Harcombe, Paul A.�� Effects of Climate Change on Southeastern Forests.� United States
����������� Geological Survey.� June 1997.� Internet.� Available online.� Accessed on:
����������� March 10, 2001.�
Hvidberg, Christine Schott. 2000.� When Greenland ice melts.� Nature.404: 551-552.
IPCCa.� Climate Change 1995: The Science of Climate Change-Summary for Policymakers.
����������� World Meteorological Organization and United Nations Environment Programme.� 1995.
IPCCb.� North America.� The Regional Impacts of Climate Change: An Assessment of
Vulnerability.� World Meteorological Organization and United Nations Environment Programme.�
Watson, Robert T.; Zinyowera, Marufu C. and Moss, Richard H., editors.
UK: Cambridge University Press.� 1998.� 253-330.
Jardine, Kevin.� The Carbon Bomb: Climate Change and the Fate of the Northern Boreal
����������� Forests.� Greenpeace International.� Goldsworthy, Lyn; Thomas, Abbie; and Szarbo,
����������� Michael.� Internet.� Available online. Accessed on: April 5, 2001.
����������� http://dieoff.org/page129.htm
Kerr, Richard A.�� 2000.� Climate Change: Greenhouse forecasting still cloudy.� Science.
������������ �276: 1040-1042.�������
Krauchi, N.� 1993.�� Potential impacts of a climate change on forest ecosystems.�
����������� EuropeanJournal of Forest Pathology.� 23: 28-50.
Lemonick, Michael D.� Life in the Greenhouse.� Time.�� Vol. 157, No. 14.� April 9, 2001. 24-29.
Leung, L. Ruby and Wigmosta, Mark S.�� 1999.�� Potential climate change impacts on�
����������� mountain watersheds in the Pacific Northwest.� Journal of the American Water
����������� Resources Association.� 35: 1463-1471.
Malcolm, Jay R. and Pitelka, Louis F.� Ecosystems and Global Climate Change: A Review of
����������� Potential Impacts on U.S. Terrestrial Ecosystems and Biodiversity.��� Pew Center on
����������� Global Climate Change.� December 2000.
Meyer, J.L.; Sale, M.J.; Mulholland, P.J.; and Poff, N. LeRoy.� 1999.� Impacts of climate change
����������� on aquatic ecosystem functioning and health. Journal of the American Water Resources
����������� Association. 35: 1373-1386.
Michaels, Patrick J. and Balling, Robert C., Jr.� The Satanic Gases: Clearing the Air about
����������� Global Warming.� Washington, D.C.: CATO Institute.� 2000.
National Assessment Synthesis Team.� Climate Change Impacts on the United States: The
����������� Potential Consequences of Climate Variability and Change.� US Global Change
����������� Research Program. UK:� Cambridge University Press.� 2000. ���
Neumann, J.E; Yohe, G.; Nicholls, R.; and Manion, M.� Sea-level Rise and Global climate
����������� Change: A Review of Impacts to U.S. coasts.� Pew Center on Global Climate Change.  February 2000.
Rauber, Paul.� Heat Wave.� Sierra.� Vol. 82, No. 5.� 2000.� 34-41.
Reid, Stephen J. Part 3: Climate Change.� Ozone and Climate Change: A Beginner's Guide.
����������� Australia:Gordon and Breach Science Publishers.� 2000.� 129-175.
Revkin, Andrew.� Global Warming: Understanding the Forecast.� New York, New York:
����������� Abbeville Press.� 1992.
Rodes, Barbara K. and Odell, Rice.� A Dictionary of Environmental Quotations.� Baltimore:
����������� The John Hopkins University Press. �1998.
The Roles of the Ocean in Climate Change.�� National Aeronautics and Space Administration.
����������� June 1999.� Internet.� Available online.� Accessed on: March 10, 2001.�
����������� http://www.gsfc.nasa.gov/ . FS-1999-06-026-GSFC
The Science of Climate Change.�� Global Climate Change-Canada.� Internet.� Available online.
����������� Accessed on: March 8, 2001.� http://www.ec.gc.ca/climate/fact/science.html
Spencer, Roy.� How do we know the Temperature of the Earth?:� Global Warming and Global
Temperatures.�� Earth Report 2000: Revisiting the True State of the Planet.�� Bailey, Ronald, editor.� New York: McGraw-Hill Companies.� 2000.� 23-40.
Sun, G.; D.M Amatya, S.G. McNulty, R.W. Skaggs, and J.H. Hughes.�� 2000.� Climate change
����������� impacts on the hydrology and productivity of a pine plantation.� Journal of the
����������� American Water Resources Association.�� 36: 367-374.
Switzer, Jacqueline Vaughn and Bryner, Gary.� Regulating Transboundary Pollution and
����������� Protecting the Global Commons.� Environmental Politics: Domestic and Global
����������� Dimensions.� 2nd Edition. New York: St. Martin's Press.� 1998.� 200-230.
Titus, James G. 1998 Rising Seas, Coastal Erosion, and the Takings Clause: How to save
����������� wetlands and beaches without hurting property owners.� Maryland Law Review.
����������� 57: 1279-1399.� Also available on the internet.� Accessed on: March 1, 2001.
����������� http://www.epa.gov/globalwarming/publications/impacts/sealevels/take_txt.html
Tolba, Mostafa K.�Climate Change.� Saving OurPlanet: Challenges and Hopes.� London: Chapman and Hall.� 1992.� 23-32.
Wolock, David M. and McCabe, Gregory J.� 1999.� Estimates of runoff using water-balance
����������� and atmospheric general circulation models.� Journal of the American Water Resources
����������� Association.� 35: 1341-1351.
Zwiers, Francis and Weaver, Andrew J.� 2000.� The Causes of the 20th Century Warming.
����������� Science.� 290: 2081-2083.
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