Coastal Geology in our National Parks

Global Climate Change and Sea-Level Rise

Coastal National Parks must consider long-term management plans to counteract the negative impacts of sea-level rise on vulnerable coastal areas. The National Park Service and the United States Geological Survey are currently developing Coastal Vulnerability Index (CVI) maps for coastal parks. These maps identify coastal areas sensitive to sea-level rise, and will allow managers to take precautions necessary for their protection.

Global Climate Change

What is causing the current trend in global climate change? This question continues to spark heated debate amongst scientists, politicians and other opinionated parties. Unfortunately, this is not an easy question to answer. It appears that the present increase in global temperature, approximately 1°F in the last century, is caused by a combination of natural and anthropogenic factors.

The Earth experiences periodic cycles (Milankovitch cycles) of global warming and cooling. The last temperature maxim occurred nearly 7,000 years ago during the middle Holocene. The analysis of historic climate data during the last 1,000, 15,000, 150,000, 1 million, and 150 million years are evidence of natural cycles of global warming throughout Earth's history. For a thorough explanation of this phenomena, please see Remembrance of Things Past: Greenhouse Lessons from the Geologic Record, a highly informative article by Thomas J. Crowley of Texas A &M University http://www.gcrio.org/CONSEQUENCES/winter96/geoclimate.html.

Boulder Glacier, Glacier National Park, Montana, July 1932 (left) and July 1988 (right), 56 years later, from the same point. The ice cave and glacier have completely disappeared. For more information, please read Melting Glaciers Signal Change in National Parks (http://www.nwrc.usgs.gov/world/content/land5.html).

The anthropogenic emission of greenhouse gases has most likely caused a further increase in global temperatures. Greenhouse gases including carbon dioxide, methane, ethane, nitrous oxide, and water vapor, work to trap heat within the Earth's atmosphere. When greenhouse gas levels increase drastically, so does the Earth's ability to retain heat. High quantities of these gases are emitted into the atmosphere through the burning of fossil fuels (oil, natural gas, coal, etc), agriculture activities, and industrial processes. The increased production of these gases is scientifically shown to have accelerated the present cycle of global warming.

NASA graphic

Please visit:
http://ww2.wrh.noaa.gov/climate_info/Global_Warming.htm - NOAA Web site on global warming with numerous links to learn more about the process of global warming.

Sea-Level Rise

Changing global temperatures will have numerous repercussions on our planet, including drastic climatic changes and sea-level rise. Eustatic (worldwide) sea levels are expected to increase 40 to 65 cm by the year 2100. As temperatures increase, sea waters expand and glaciers melt. Even a minor increase in sea level will have drastic effects on coastal environments. When sea level increases, shorelines, barrier islands and wetlands may adjust by moving in a landward direction. Unfortunately, the use of hard structures (jetties, groins, seawalls, etc.) to stabilize the shoreline makes landward movement impossible, causing the flooding and eventual collapse of these vital ecosystems. Even a moderate increase in sea level may lead to the gradual extinction of many coastal environments and species. The Environmental Protection Agency (EPA) predicts that the United States will be the country most impacted by sea level rise. In the US, the greatest damage will occur on the Atlantic Coast, where even a small increase in sea level will have drastic effects on the fragile coastal environments found within the shallow coastal plain.

The following links are excellent sites for in-depth information concerning the Greenhouse Effect, Global Warming, and the effects of Sea Level Rise on Coastal Environments. In addition, we have included sites defining the Kyoto Protocol, and opposing views to greenhouse-induced global warming.

http://yosemite.epa.gov/oar/globalwarming.nsf/content
/ResourceCenterPublications SeaLevelRiseIndex.html - US Environmental Protection Agency links to publications concerning sea level rise.

http://www.epa.gov/globalwarming/ - Excellent Environmental Protection Agency (EPA) web site that features a wealth of information covering climate, emission, impacts and actions. This site also has a information for concerned citizens, coastal residents, kids, educators, etc.

http://www.nap.usace.army.mil/cenap-en/slr_links.htm - Army Corp of Engineers page with numerous links to government, university, and non-profit environmental web sites, featuring information on sea level rise, climate change and greenhouse gas emissions.