Update on the

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Update on the Chesapeake 2000 Commitment
CLIMATE CHANGE AND CHESAPEAKE BAY
by the Living Resources Subcommittee
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The C2K Commitment to
Evaluate the potential impact of climate change
on the Chesapeake Bay watershed, particularly
with respect to its wetlands, and consider
potential management options.
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What will be the amount and rate of future
climate changes? What impacts will those
changes have on Bay ecosystems?
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Climate Projections for the Mid-Atlantic Region
Parameter 2030 2095 Confidence in Projection
CO2 (ppm) 20 to 30 50 to 120 Very high
Sea Level (inches) 4 to 12 15 to 40 High
Air Temperature (0F)a 1.8 to 2.7 4.9 to 9.5 High
Precipitation ()a -1 to 8 6 to 24 Medium
Runoff ()b -2 to 6 -4 to 27 Low
a Range given by Hadley and CCC models for the
Northeast U.S. b For the Susquehanna River
Basin, using a water balance model forced with
the CCC and Hadley output
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Summary of Impacts in the Mid-Atlantic Region
Negative Impacts Positive Impacts
Most Certain Agricultural Production Coastal Zones Temperature related health (urban heat stress)
Moderately Certain Forestry Production Temperature related health (cold stress)
Uncertain Biodiversity Fresh Water Quantity Fresh Water Quality Ecological Function Vector and Water-borne Disease Environmental Effects from Agriculture
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What may be the major consequences of climate
change in the Bay watershed?
Variability and extremes in precipitation,
temperature, dissolved oxygen, water quality,
salinity
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Global mean surface temperatures have increased
0.5-1.0F since late 19th century and could rise
1.6-6.3F by 2100, with significant regional
variation.
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Temperature has varied in the past, with a
pronounced increase in the range of temperature
variation during the last 300 years.
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What may be the major consequences of climate
change in the Bay watershed?
Sea Level Rise
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In Maryland, sea level has risen approx. 3-4
mm/year (12-15 inches /century) due to global sea
level rise and regional (post-glacial) subsidence
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HISTORIC MID-ATLANTIC SEA LEVEL RISE (mm/year)
MEAN SEA RISE RATES Global 1.8mm/yr
Maryland 3-4mm/yr
Larsen 1998. Rising Sea Level in the Chesapeake
Bay. USGS.
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What may be the major consequences of climate
change in the Bay watershed?
Loss of coastal wetlands
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Lands vulnerable to sea level rise in the
Chesapeake Bay watershed are predominantly
existing tidal wetlands
(from the Mid-Atlantic Integrated Assessment)
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Stevenson, Kearney and Koch (in press) Impacts
of Sea Level Rise on Tidal Wetlands and Shallow
Water Habitats A Case Study from Chesapeake Bay,
in N. McGinn, Fisheries in a Changing Climate,
Amer. Fisheries Society, Bethesda MD
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What may be the major consequences of climate
change in the Bay watershed?
Ecosystem losses and gains (biodiversity, species
composition)
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Multiple Stresses of a Changing Climate
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Climate change may result in loss of habitat,
biodiversity, and ecosystem function throughout
the Bay.
SHALLOW WATER AREAS
COASTAL WETLANDS
OPEN WATER AREAS
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CLIMATE CHANGE VULNERABILITY AND ADAPTATION
The large scale features of climate change are
well understood, but the projections of change at
regional and smaller scales remain uncertain.
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Key Climate Change Issues for Chesapeake Bay

• The causes and effects of climate variability
  remain uncertain in the Mid-Atlantic.
• Climate change is currently in the general
  assessment phase on the national level.
• Next phase of the national and regional
  assessments -
• Quantitative assessments
• Mitigation and adaptation strategies
• Impacts related to climate change may be
  substantial for some Bay resources.

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Next Steps for the Bay Program

• Hold a working workshop to identify climate
  change issues to be considered by subcommittees
  during development of workplans to address the
  C2K climate change commitment
• Seek funding for education and outreach through
  the development of CBP budget proposals or other
  sources
• Collaborate with climate change initiatives being
  developed by the jurisdictions

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Next Steps for the Bay Program cont.

• Workshop Topics
• In order to plan effectively for climate change,
  the CBP should adopt an adaptive management
  approach which considers future climate
  variability.
• The expected range of conditions or extreme
  conditions should be considered in developing
  goals and management approaches versus average
  historical conditions.
• Increase awareness of potential impacts of
  climate change with respect to CBP subcommittee
  and workgroup activities, strategies, and
  workplans

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Next Steps for the Bay Program cont.

• Hold a working workshop to identify climate
  change issues to be considered by subcommittees
  during development of workplans to address
  assigned commitments
• Seek funding for education and outreach through
  the development of CBP budget proposals or other
  sources
• Collaborate with climate change initiatives being
  developed by the jurisdictions