An overview of climate change effects potentially impacting the Southeastern United States. Provides references, image credits, and supporting citations in "slide notes" view. For more climate change information, visit the National Biological Information Infrastructure (NBII), Southeast Information Node Climate Change Web site at http://go.usa.gov/OIs
13. Changes in Particularly
Sensitive Ecosystems
Higher air temperatures result in more ground-
level ozone formation, damaging sensitive
plant communities
19. Forest fires burn more intensely as evaporation
increases and forests dry
20. Forage quality is altered as plant communities
change under elevated carbon dioxide levels
21. Climate Change Impacts
• The potential impacts of
climate change are
diverse
• Some climate impacts
are already apparent
• Other impacts are
predicted to occur as
Earth's climate
continues to change
Notas do Editor
Eastern U.S. after snowfall. [Photo: SeaWiFS, National Aeronautics and Space Administration (NASA), Earth Observing Satellite Project Science Office]
This data visualization from the AMSR-E instrument on the Aqua satellite show the maximum sea ice extent for 2008-09, which occurred on Feb. 28, 2009. [Photo: NASA Goddard's Scientific Visualization Studio, National Aeronautics and Space Administration (NASA)] Climate change is defined by the U.S. Geological Survey as “long-term alteration in the characteristic weather conditions of a region, such as changes in precipitation and temperature.” Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level. (Intergovernmental Panel on Climate Change , 2007).
Artist concept of the sun and Earth. [Photo: National Aeronautics and Space Administration (NASA), Goddard Space Flight Center] Paleoclimatologists have long suspected that the "middle Holocene" or a period roughly from 7,000 to 5,000 years ago, was warmer than the present day. (National Atmospheric and Oceanic Administration , National Climatic Data Center, 2008).
Greenhouse gases create a "greenhouse effect," warming the planet by trapping radiant energy from the sun similar to how a greenhouse traps heat from the sun. [Photo: Barb Deluisi, National Oceanic and Atmospheric Administration (NOAA)] The greenhouse effect is a natural phenomenon whereby certain gases in the earth’s atmosphere, known as greenhouse gases, absorb heat that would otherwise escape to space (Pew Center on Global Climate Change, 2009). Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely [i.e. greater than 90% certainty] due to the observed increase in anthropogenic greenhouse gas concentrations. (Intergovernmental Panel on Climate Change, 2007) Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level. (Intergovernmental Panel on Climate Change, 2007)
Recalling the famous Apollo-era pictures of Earth taken by lunar astronauts, this digital image is a portrait of the Western Hemisphere at the time of one of the strongest hurricanes ever observed in the Eastern Pacific. The presence of the Moon in this image is an artistic addition. The lunar image was collected by GOES in September 1994, and has been magnified to about twice its relative size. [Photo: Goddard Space Flight Center, National Aeronautics and Space Administration (NASA)] The projected effects of climate change include warmer and fewer cold days and nights over most land areas, warmer and more frequent hot days and nights over most land areas, increased frequency of warm spells and heat waves over most land areas, increased frequency of heavy precipitation events over most areas, increase in areas affected by drought, increase in intense tropical cyclone activity, and a rise in sea level. (Intergovernmental Panel on Climate Change, 2007)
Sandhill crane ( Grus canadensis ) in flight. [Photo: Dave Herr, United States Department of Agriculture (USDA), Forest Service] Large-scale shifts have occurred in the ranges of species and the timing of the seasons and animal migration, and are very likely to continue [. . .]. For butterflies, birds, and other species, one of the concerns with such changes in geographic range and timing of migration is the potential for mismatches between species and the resources they need to survive (U.S. Global Change Research Program, 2009) Existing and possible impacts include [… ] shifts in migratory patterns of birds, fish, and other animals, such as the timing and distance of migrations, and fluctuations in the seasonal behavior of plants, such as plants flowering before pollinators are present. (U.S. Fish and Wildlife Service, Asheville Field Office)
An American alligator ( Alligator mississippiensis ) and a Burmese python ( Python molurus ) are pictured locked in a struggle to prevail in Everglades National Park. [Photo: Lori Oberhofer, United States National Park Service (USNPS)] As temperatures and precipitation patterns shift in response to climate change, species ranges will also shift. (U.S. Global Change Research Program, 2009) In the U.S., species restricted to southern habitats may move north as milder winters allow overwintering. (U.S. Environmental Protection Agency, 2008) Many more Americans live in counties having climate similar to that found in the native range of the python. Many more Americans live in areas that could be colonized by Indian Pythons if the global climate warms as predicted by many models (Rodda, G.H., Jarnevich, C.S., and Reed, R.N, (2008). Some species do not require climate change to damage ecosystems, yet climate change may exacerbate the damage they do cause. (U.S. Environmental Protection Agency, 2008) Fires, insect pests, disease pathogens, and invasive weed species have increased, and these trends are likely to continue. (U.S. Environmental Protection Agency, 2008)
The maps show current and projected forest types. Major changes are projected for many regions. For example, in the Northeast, under a mid-range warming scenario, the currently dominant maple-beech-birch forest type is projected to be completely displaced by other forest types in a warmer future. [Photo: United States Global Change Research Program,] In North America, warming has generally resulted in and is expected to continue to result in shifts of species ranges poleward and to higher altitudes. (National Science and Technology Council, Report of the Committee on Environment and Natural Resources, 2008) Simulations suggest that part of the [Southeast’s] forest will possibly be replaced by savannas and grasslands due to decreased soil moisture and fire. (U.S. Global Change Research Program, 2009) Rapid climate change is expected to dramatically alter the distribution, function, and disturbance regimes of natural ecosystems. (U.S. Department of Agriculture, Forest Service, Climate Change Resource Center, 2008) The rate of future climate change is likely to exceed the migration rates of most plant species. The replacement of dominant species by locally rare species may require decades, and extinctions may occur when plant species cannot migrate fast enough to escape the consequences of climate change. (Neilson, 2005)
A wetland in Morristown, Hamblen County, Tennessee. This is a stopover for migratory birds of all kinds. Even the cattails are dying, according to the photographer. Picture was taken on September 12, 2007 in central east Tennessee to document the drought of 2007. [Photo: Brian Boyd, National Weather Service Southern Region, Morristown Weather Station] Drought frequency and severity are projected to increase in the future over much of the United States, particularly under higher emissions scenarios. (U.S. Global Change Research Program , 2009) The increase in very hot days will have consequences for human health, drought, and wildfires. (U.S. Global Change Research Program , 2009) Warming over the past several decades has fundamentally altered the hydrologic cycle, and these changes are percolating through our watersheds … Precipitation patterns may change, and floods, droughts, and severe weather disturbances may become more common. (U.S. Department of Agriculture, Forest Service, 2008) The frequency and severity of droughts could increase in some areas as a result of a decrease in total rainfall, more frequent dry spells, and greater evapotranspiration. ( Frederick, K.D., Gleick, P.H., 1999)
Adult southern pine beetle in flight. [Photo: Erich Vallery, United States Department of Agriculture (USDA), Forest Service, Southern Research Station] Disease pressure on crops and domestic animals will likely increase with earlier springs and warmer winters, which will allow proliferation and higher survival rates of pathogens and parasites. (National Science and Technology Council, Report of the Committee on Environment and Natural Resources, 2008) The combination of drought and high temperatures also has led to serious insect infestations and death of piñon pine in the Southwest, and to various insect pest attacks throughout the forests of the eastern United States. (U.S. Global Change Research Program , 2009)
This 2006 photograph depicted a female Aedes aegypti mosquito while she was in the process of acquiring a blood meal from her human host. Note the distended abdominal exoskeleton, which being translucent, allowed the color of the ingested blood meal to be visible. This female’s abdomen had become distended due to the blood meal she was ingesting, imparting the red coloration to her translucent abdominal exoskeleton. [Photo: James Gathany, Centers for Disease Control] One consequence of a longer, warmer growing season and less extreme cold in winter is that opportunities are created for many insect pests and disease pathogens to flourish. (U.S. Global Change Research Program , 2009) Evidence for the United States indicates that climate affects both the abundance of vectors and ticks and the distributions of vectors and ticks that can carry West Nile virus, Western Equine encephalitis, Eastern Equine encephalitis, Bluetongue virus, and Lyme disease. (National Science and Technology Council, Report of the Committee on Environment and Natural Resources, 2008)
Boll weevil ( Anthonomus grandis) on a young cotton boll. [Photo: United States Department of Agriculture (USDA), Agricultural Research service] Many insect pests and crop diseases thrive due to warming, increasing losses and necessitating greater pesticide use. Warming aids insects and diseases in several ways. Rising temperatures allow both insects and pathogens to expand their ranges northward. In addition, rapidly rising winter temperatures allow more insects to survive over the winter, whereas cold winters once controlled their populations. Some of these insects, in addition to directly also carry diseases that harm crops. (U.S. Global Change Research Program, 2009)
Ozone damage to maple. [Photo: Robert L. Anderson, USDA Forest Service, Bugwood.org] Ground-level ozone formation increases with greater sunlight and higher temperatures. (National Science and Technology Council, Report of the Committee on Environment and Natural Resources, 2008) Ozone levels in the troposphere, the part of the atmosphere closest to land, have increased due to human activities. (U.S. Department of Agriculture, Forest Service, 2008). Climate change has the potential to produce significant increases in ground-level ozone in many regions, particularly for the highest-ozone events. (U.S. Environmental Protection Agency, 2009)
View from Mt. Cammerer in winter, Great Smoky Mountains National Park, Tennessee. [Copyright: Tanner Jessel, used with permission] Animal and plant species that live in the mountains are among those particularly sensitive to rapid climate change. (U.S. Global Change Research Program , 2009) In the Southern Appalachians, these species also found homes in the cold, harsh climate found on the tops of high highest mountains [...] The rising temperatures expected with climate change are of particular concern with respect to these cold-dependent species. (U.S. Fish and Wildlife Service, Asheville Field Office, 2009) Northern Flying Squirrels, Rock Voles and Red squirrels, which are found in high elevation, cool, humid habitats are at risk. (Wathen, H., Edelson, N., and Hancock, G., 2009)
Brook trout swims in native stream. [Photo: Eric Engbretson, NCTC Image Library, U.S. Fish and Wildlife Service] The habitats of some mountain species and coldwater fish, such as salmon and trout, are very likely to contract in response to warming salmon and trout, are very likely to contract in response to warming. (U.S. Global Change Research Program , 2009) The coldest headwaters and spring influenced habitats are at risk of being lost. (Wathen, H., Edelson, N., and Hancock, G., 2009) According to Flebbe’s model, between 53 and 97 percent of wild trout populations in the Southern Appalachians could die out as streams become warmer. Trout are coldwater species that depend on relatively low stream temperatures to survive. (U.S. Department of Agriculture, Forest Service, 2008)
Pictures taken on September 12, 2007 from across central east Tennessee showing the drought of 2007. Photograph captures view from middle of boat ramp on Douglas Lake, Cocke County, TN looking up toward boat docks. [Photo: Brian Boyd, National Weather Service Southern Region, Morristown Weather Station] Climate change is one of several human-induced stresses that threaten to intensify and extend these adverse impacts to biodiversity, ecosystems, and the services they provide. (U.S. Global Change Research Program , 2009) Evidence is mounting that human-induced climate change is already altering many of the existing patterns of precipitation in the United States, including when, where, how much, and what kind of precipitation falls. […] Much of the South-east and West has had reductions in precipitation and increases in drought severity and duration, especially in the Southwest […] The negative effects of water pollution, including sediments, nitrogen from agriculture, disease pathogens, pesticides, herbicides, salt, and thermal pollution, will be amplified by observed and projected increases in precipitation intensity and longer periods when streamflows are low. (U.S. Global Change Research Program , 2009) Climate change will impact the ability of the Nation’s forests to provide water and other critical watershed services. [Example: More evapotranspiration resulting from higher temperatures leads to drier vegetation and soils, more frequent and severe droughts, and increased wildfires and area burned.] (U.S. Department of Agriculture, Forest Service, 2008) Climate change will affect water availability - quantity, quality, timing, and distribution - and other watershed services (U.S. Department of Agriculture, Forest Service, 2008) Water quality is sensitive to increased water temperatures, changes in precipitation, and other climate-related factors. (National Science and Technology Council, Report of the Committee on Environment and Natural Resources, 2008) Dissolved oxygen is reduced in lakes, reservoirs, and rivers at higher temperatures. (U.S. Global Change Research Program , 2009) Water quality problems may increase where there is less flow to dilute contaminants introduced from natural and human sources. ( Frederick, K.D., Gleick, P.H., 1999)
September 2009 Flooding Chattahoochee River below Morgan Falls Dam: USGS hydrographer preparing to measure streamflow at the Chattahoochee River below Morgan Falls Dam water-monitoring site. [Photo: Alan Cressler, United States Geological Survey (USGS)] Almost all global climate change models predict higher temperatures, variable rainfall, and more frequent and intense storms. (U.S. Department of Agriculture, Forest Service, 2008). The intensity of extreme precipitation events (i.e., events of 2 inches or more within a 24 hour period) have increased by over 30% during the past century. [. . .] Models also project more frequent El Niño-like conditions with increased extreme rainfall event frequency. (Treasure, E.A., Cohen, E., and McNulty S.G.,2008) Over the past 100 years, intense precipitation events have increased across the South. This trend is projected to continue, raising the likelihood of flooding and erosion. (U.S. Department of Agriculture, Forest Service, 2008) Water quality can also be affected by extreme precipitation events, the frequency of which are likely to continue to increase. (U.S. Global Change Research Program , 2009)
Wildfires in Appalachian Mountains and southeast United States: Drought conditions have plagued the Appalachian Mountains in October and November, and low relative humidity combined with dry leaves on the ground has created extreme fire danger in many eastern states. This true-color MODIS image made from data collected on November 13, 2001, shows smoke from numerous fires (indicated in red), predominantly in southern West Virginia ,Kentucky ,and Tennessee (south). [Photo: Goddard Space Flight Center,National Aeronautics and Space Administration (NASA)] Because higher temperatures lead to more evaporation of moisture from soils and water loss from plants, the frequency, duration, and intensity of droughts are likely to continue to increase. (U.S. Global Change Research Program , 2009) The percentage of the Southeast in moderate to severe drought increased over the past three decades. (U.S. Global Change Research Program , 2009) The area of moderate to severe spring and summer drought has increased by 12 percent and 14 percent, respectively, since the mid 1970s. Even in the fall months, when precipitation tended to increase in most of the region, the extent of drought increased by 9 percent. (U.S. Global Change Research Program , 2009) Wherever droughts increase, forest productivity will decrease and tree death will increase […] these conditions are projected to occur in […] the eastern part of the Southeast. (U.S. Global Change Research Program , 2009) Prone to natural weather disasters, the Southeast will be further impacted by changes in temperature and precipitation that alter the frequency, intensity, duration, and timing of disturbances such as wildfire, drought, invasive species, insect and pathogen outbreaks, and hurricanes. (U.S. Department of Agriculture, Forest Service, 2008) The Hadley model suggests wetter weather overall for the Southeast, while the Canadian model suggests drier, with widespread droughts that may transform some forested areas into savannas. (U.S. Department of Agriculture, Forest Service, 2008). Some climate models suggest that rainfall associated with El Niño and the intensity of droughts during La Niña phases will be intensified as atmospheric CO2 increases. (U.S. Global Change Research Program , 2009)
2007 Georgia Wildfires burn a pine stand. [Photo: National Interagency Fire Center Archive, Bugwood.org] More evapotranspiration resulting from higher temperatures leads to drier vegetation and soils, more frequent and severe droughts, and increased wildfires and area burned. (U.S. Department of Agriculture, Forest Service, 2008). Climate change makes droughts worse, causing worse insect outbreaks and worse fires. (U.S. Department of Agriculture, Forest Service, 2008). CO2 has increased about 30 percent in the last century, with little or no tree growth effect detected, while forest diebacks have become more common, especially from climate change-induced increases in insects and wildfires. (U.S. Department of Agriculture, Forest Service, 2008). Trees killed by insects also provide more dry fuel for wildfires. (U.S. Global Change Research Program , 2009)
A photo of an elk ( Cervus elaphus ) grazing. [Photo: U.S. National Park Service] Forage quality in pastures and rangelands generally declines with increasing carbon dioxide concentration because of the effects on plant nitrogen and protein content, reducing the land’s ability to supply adequate livestock feed. (U.S. Global Change Research Program , 2009) A higher atmospheric carbon dioxide concentration causes trees and other plants to capture more carbon from the atmosphere, but experiments show that trees put much of this extra carbon into producing fine roots and twigs, rather than new wood. (U.S. Global Change Research Program , 2009) “ Elevated levels of carbon dioxide in the atmosphere are having quite a different impact on trees, often referred to as a fertilizing effect,” however,“[w]herever droughts increase, forest productivity will decrease and tree death will increase […] these conditions are projected to occur in […] the eastern part of the Southeast. (U.S. Global Change Research Program , 2009) The increasing carbon dioxide concentration stimulates the growth of most plant species, and some invasive plants respond with greater growth rates than native plants. (U.S. Global Change Research Program , 2009)
Works Cited: Frederick, K.D., Gleick, P.H., (1999). Water & Global Climate Change: Potential Impacts on U.S. Water Resources . Retrieved April 26, 2010, from Web site: http://www.pewclimate.org/docUploads/clim_change.pdf Intergovernmental Panel on Climate Change (IPPC). (2007). Climate Change 2007: Synthesis Report. Retrieved April 26, 2010, from Web site: http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf National Assessment Synthesis Team, U.S. Global Change Research Program. (2000). Southeast mega-region from Overview of Climate Change Impacts on the United States: The Potential Consequences of Climate Variability and Change . Retrieved April 26, 2010, from Web site: http://www.usgcrp.gov/usgcrp/Library/nationalassessment/6SE.pdf National Atmospheric and Oceanic Administration (NOAA), National Climatic Data Center. (2008). The Mid-Holocene "Warm Period." Retrieved April 26, 2010, from Web site: http://www.ncdc.noaa.gov/paleo/globalwarming/holocene.html National Science and Technology Council, Report of the Committee on Environment and Natural Resources. (2008). Scientific Assessment of the Effects of Global Change on the United States. Retrieved April 26, 2010, from Web site: http://www.amwa.net/galleries/climate-change/CCSP_Report_May08.pdf Neilson, Ron. (2005). Vegetation Distribution and Climate Change. U.S. Department of Agriculture, Forest Service, Climate Change Resource Center. Retrieved April 26, 2010, from Web site: http://www.fs.fed.us/pnw/pubs/journals/uncaptured/pnw_2005_neilson001.pdf Pew Center on Global Climate Change. (2009) Realities vs. Misconceptions about the Science of Climate Change. Retrieved April 26, 2010, from Web site: http://www.pewclimate.org/docUploads/climate-science-misconceptions-and-facts-aug2009_0.pdf Pew Center on Global Climate Change. (2009). Science Brief: The Causes of Climate Change. Retrieved April 26, 2010, from Web site: http://www.pewclimate.org/docUploads/global-warming-science-brief-august08.pdf Rodda, G.H., Jarnevich, C.S., and Reed, R.N. (2008). What Parts of the U.S. Mainland Are Climatically Suitable for Invasive Alien Pythons Spreading from Everglades National Park? Retrieved April 26, 2010, from Web site: http://www.fort.usgs.gov/Products/Publications/21972/21972.pdf Treasure, E.A., Cohen, E., and McNulty S.G. (2008). Vulnerability of the Southeastern United States to Climate Change. Retrieved April 26, 2010, from Web site: http://www.worldwildlife.org/who/media/press/2008/WWFBinaryitem9647.pdf U.S. Department of Agriculture (USDA), Forest Service (USFS). (2008). In Brief: Climate Change and Water. Retrieved April 26, 2010, from Web site: http://www.fs.fed.us/ccrc/files/CC%20and%20Water%20In%20Brief.pdf U.S. Department of Agriculture (USDA), Forest Service (USFS). (2008). What do Forests have to Do with Global Climate Change? Retrieved April 26, 2010, from Web site: http://www.srs.fs.usda.gov/compass/issue10/issue10.pdf U.S. Department of Agriculture (USDA), Forest Service (USFS), Climate Change Resource Center (CCRC). (2008). Vegetation Distribution and Climate Change. Retrieved April 26, 2010, from Web site: http://www.fs.fed.us/ccrc/topics/vegetation.shtml U.S. Environmental Protection Agency. (2009). EPA Report Provides an Assessment of Potential Impacts of Climate Change on U.S. Regional Air Quality. Retrieved April 26, 2010, from Web site: http://www.epa.gov/ord/npd/pdfs/ca-factsheet-aq.pdf U.S. Environmental Protection Agency. (2008). Effects of Climate Change on Aquatic Invasive Species and Implications for Management and Research. Retrieved April 26, 2010, from Web site: http://www.elistore.org/Data/products/d18_04.pdf U.S. Fish and Wildlife Service, Asheville Field Office. (2009). Climate Change: Conservation Issues in the Asheville Field Office. Retrieved April 26, 2010, from Web site: http://www.fws.gov/Asheville/pdfs/ClimateChange.pdf U.S. Geological Survey (USGS). (2005). Climate Change. Retrieved April 26, 2010, from Web site: http://www.usgs.gov/science/science.php?term=168 U.S. Global Change Research Program. (2009). Global Climate Change Impacts in the United States: Ecosystems. Retrieved April 26, 2010, from Web site: http://www.globalchange.gov/images/cir/pdf/ecosystems.pdf U.S. Global Change Research Program . (2009). Regional Climate Impacts: Southeast. Retrieved April 26, 2010, from Web site: http://downloads.globalchange.gov/usimpacts/pdfs/southeast.pdf U.S. Global Change Research Program. (2009). Global Climate Change Impacts in the United States: Agriculture. Retrieved April 26, 2010, from Web site: http://www.globalchange.gov/images/cir/pdf/agriculture.pdf U.S. Global Change Research Program. (2009). Global Climate Change Impacts in the United States: Water Resources. Retrieved April 26, 2010, from Web site: http://downloads.globalchange.gov/usimpacts/pdfs/water.pdf Wathen, H., Edelson, N., and Hancock, G. (2009). Climate Change and Potential Impacts to Wildlife in Tennessee. Retrieved April 26, 2010, from Web site: http://tennessee.gov/twra/pdfs/climatefacts.pdf
