Impacts of Climate Change on Coastal Virginia and Chesapeake Bay: Physical, Geological and Biogeochemical Processes James E. Bauer Virginia Institute of Marine Science Virginia Governor s Commission on Climate Change April 2008 Initiative for Coastal Climate Change Research
Williamsburg Campus Jim Bauer bauer@vims.edu Ph: (804) 684-7136 Initiative for Coastal Climate Change Research
Overview Drivers of climate change -Global -Regional, w/ particular emphasis on coastal VA environments Impacts on Coastal Physical Processes: temperature, salinity, circulation, rainfall and river runoff, etc. current reality vs. future predictions Impacts on Coastal Geology: river and bay sediment supplies, shorelines, etc. Impacts on Coastal (Biogeo)Chemical Processes - nutrients, oxygen, and acidification Implications of Changes in these Processes for Coastal Ecosystems, Living Resources, etc. To be covered during Dr. Emmett Duffy s talk up next
Ice Core Records (Antarctica) record changes in Earth s climate 400 Present-day atmospheric CO 2 (~385 ppm)... and rapidly increasing Relative temperature difference (deg. C) +2 0-10 Human population
So what does this mean for the Commonwealth of Virginia? From IPCC 2007
Climate Change Factors Relevant to the Coastal Zone IPCC (2007) Coastal Systems and Low-Lying Areas
Climate Change and Sea Level Rise Concerns Specific to Estuaries and Coastal Regions Higher coastal water levels and greater salinities Increased water stratification due to rising sea level, increases in freshwater input Shoreline erosion and submergence due to rising sea level, storms, decreases in sediment delivery Increasing nutrient inputs from land, rivers Decreases in oxygen content of estuarine waters due to increasing temps. and changing circulation patterns Decreasing ph (increasing acidity) due to rising CO 2... all with significant ramifications for coastal, bay and estuarine plants, animals, food webs and ecosystems Coastal VA population 1.5-2 million (~7.6 million total) VA Atlantic coast property values ~$130 billion
Summary of Climate-Related Impacts on Socio-Economic Sectors in the Coastal Zone IPCC (2007) Coastal Systems and Low-Lying Areas
Measured Sea Level Changes in Chesapeake Bay Waters (vs. 1950-2000 mean) 0.2 0.15 0.1 Baltimore Sewells Point Sea level anomaly (m) 0.05 0-0.05-0.1-0.15 Relative Sea Level Rise Along the East Coast of North America -0.2-0.25 Six sites measured: 2.7 to 4.5 mm/yr; average = 3.5 mm/yr 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 year From STAC Report (draft April 2008) From Zhang et al. (2004) Climatic Change 64: 41 58.
Measured Temperature Changes in Chesapeake Bay Surface Waters 18 17.5 17 VIMS pier CBL pier Bay average 16.5 Temperature ( C) 16 15.5 15 14.5 14 13.5 ~ 0.3 C per decade 13 1930 1940 1950 1960 1970 1980 1990 2000 2010 year From Austin (2002) American Fisheries Society Symposium, 32, 155-170 and Secor and Wingate (2008) manuscript in prep.
York River Estuary 40 Water Temperature Anomaly (No. Winter Spring Days < 10 C) 20 0-20 -40 1968 1969 50 yr mean nd 2004 2006 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Warmer Year Courtesy of R. Condon and D. Steinberg (VIMS), manuscript submitted to Marine Ecology Progress Series.
Recent Precipitation Patterns in Virginia selected sites National Atmospheric Deposition Program Charlottesville Horton s Stn. Shenandoah Nat l Park http://nadp.sws.uiuc.edu/sites/sitemap.asp?state=va
Long-Term Changes in River Water Inputs to Chesapeake Bay Implications for materials transported by rivers, e.g., nutrients sediments, etc. and their impacts on ecological and geological processes in the Bay and along the coast http://md.water.usgs.gov/monthly/bay.html
Emissions (Pg C yr -1 ) 30 20 10 0 a Future Trends in Climate Change Drivers Under Different Scenarios CO 2 (ppm) 1000 800 600 400 b temp. change ( C) Sea level change (mm) 4 2 0 1000 500 c d A1B A1T A1FI A2 B1 B2 0 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 year From IPCC (2007) and STAC Report (draft April 2008)
What Does the Future Hold for the Bay? -Predictions from Model Results (using A2 socio-economic scenario) From STAC Report (draft April 2008)
What Does the Future Hold for the Bay? - Model Results using 6 socio-economic scenarios temperature change ( C) 6 5 4 3 2 1 a Average of all models Average of CCCM, ECHM, HADC & NCAR b 0 Precipitation change (%) 12 10 8 6 4 2 c A1B A1T A1FI A2 B1 B2 d 0 2010-39 2040-69 2070-99 Time period 2010-39 2040-69 2070-99 Time period From STAC Report (draft April 2008)
Hampton Roads Inundation Estimates Under Different Sea Level Rise Scenarios Extent of flooding is a function of: - height of water - land elevation - land relief With increasing sea level, additional flooding from storm surge effects will be greater than previously - smaller storms will have equivalent destruction potential as larger storms pre-slr Important implications for both human populations as well as living resources and coastal environments From Titus and Wang (2008) EPA.
Shoreline Evolution in Virginia Coastal Regions Function of: -SLR, storm surge -Decreased sediment supply due to river damming, shoreline protection efforts such as bulkheads, etc.
Shoreline Losses are Expected to Increase Under Current SLR Rates, Exacerbated by Storm Damage - Northumberland County (Northern Neck), VA Potomac R. Ches. Bay Red = 1937 Brown = 1969 Black = 1994 Pink = 2002 From Hardaway et al (2001) and (2006) DEQ - NOAA Reports (VIMS).
Hurricane Isabel September 18, 2003 Photos courtesy of S. Hardaway, VIMS
Shoreline Recession, Eastern Shore VA Parramore Island (Atlantic side) Virginian-Pilot, Sept. 18, 2005 From Zhang et al. (2004) Climatic Change 64: 41 58. Cedar Island (Atlantic side)
Chesapeake Bay Hypoxia How will Bay hypoxia be affected by: -Changing (increasing?) freshwater inputs by rivers, which control circulation, stratification and nutrient inputs (= eutrophication)? - Increasing Bay water temps., which decrease oxygen content? Illustration courtesy of R. Mann, VIMS
The ocean s uptake of excess CO 2 is also leading to another problem... CO 2 air ocean H 2 CO 3 (carbonic acid) ocean acidification Today 7.8 7.9 8.0 8.1 8.2 Average ocean ph ~750 ppm atm CO 2 (~2100 A.D.) Pre-industrial
Coccolithophores microscopic calcium carbonate-forming marine plants (phytoplankton) Normal CO 2 Elevated CO 2 Scanning Electron Micrographs (SEM) of E. huxleyi If phytoplankton, which form the basis for much of the coastal food web, are negatively impacted by ocean acidification, what are the implications for the rest of the food web? Riebesell et al. 2000. Nature 407: 364-367.
Other members of coastal ecosystems under serious threat globally from temperature increases, ocean acidification, etc. Acidification caused problems with shell (calcium carbonate) formation and with organisms physiology (both plants and animals)
Recommended reading- 1) IPCC Fourth Assessment Report Working Group II Report - Impacts, Adaptation and Vulnerability Coastal Systems and Low-Lying Areas http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-chapter6.pdf 2) Climate Change and the Chesapeake Bay: State-of-the-Science Review and Recommendations A Report from the Chesapeake Bay Program Science and Technical Advisory Committee (STAC) about to be released