Climate Change:
Our Challenge for the 21st Century
Dr. Susan S. Kilham Department of Biodiversity, Earth and Environmental Science
Drexel University
Jennifer Adkins Executive Director
Partnership for the Delaware Estuary
Sources of Information
From the Partnership for the Delaware Estuary:
2007: Estuary News: Climate Change Hits Home
2010: Climate Change and the Delaware Estuary
2011: Weathering Change
2012: Technical Report for the Delaware Estuary and Basin
From Pennsylvania State University:
2013: Pennsylvania Climate Impacts Assessment Update
Local Impacts of Climate Change in this
Century
Increased temperatures (up to 4°C
(7.2°F)by 2100-A2)
Increased precipitation
Increased evapotranspiration
Decreased soil moisture
(except in spring)
Increased stream temperatures
Increased salinity ( sea levels + stream
flow)
But, Also Consider
Population growth
Urbanization and other
land cover changes
Pollution of water bodies
These could be equal or even greater stressors than
climate change, especially in the near future
Consequences of Changes:
Temperature
Increased temperatures cause decreased
oxygen concentrations.
Additionally, increased N-oxygen demand from
increased NH4 loading
Consequences for sensitive fish species,
especially YOY sturgeon and cold water species
Increased NH4 loading also affects FW mussels
Changes in growing season, phenology misfits
Consequences of Change:
Precipitation
General increase in precipitation in the last 30 years
Increased seasonal variability in precipitation: greater in winter/spring and less in summer
Less snow, shorter snow cover duration
Increased frequency of heavy precipitation events (changes in channel morphology, flushing of contaminants, erosion of stream banks, higher sediment loads)
Decreased survival and reproductive success for fish and macroinvertebrates.
Consequences of Change:
Evapotranspiration
Precipitation during growing season is returned nearly completely to the atmosphere via evapotranspiration
Lengthening of growing season increases evapotranspiration
Water levels in streams in summer/fall will decline
Low flows and higher temperatures are likely to decrease habitat suitability for aquatic organisms (low O2, increased flow variability, timing of peak flows and changes in stream T)
Consequences of Change:
Soil Moisture Soil moisture droughts will increase because of
higher T and lower precipitation during summers.
This trend is already apparent.
Wetter winters over frozen soils leads to greater
runoff, even floods.
Groundwater recharge occurs mostly in spring,
but increased precipitation is unlikely to
compensate for excessive withdrawals.
Consequences of Change:
Increased Salinity Drinking water for 15 million people (DRBC: Na <
50ppm; AHA Na < 20 ppm). Chloride
is expected to increase 4X in Philadelphia by 2100
Sea level increase (globally up to 1.4 m , but
regionally higher by 2100)
Severe impacts to wetlands
with critical problems for
wetland species
Oyster growth and survival
will be impacted
A Few Particular Concerns
Adjusting the traditional paradigm of restoration to past conditions to the reality of climate change
Protecting source water quantity and quality
Wetland/salt marsh issues
Species disconnects in phenology
Barriers to species migrations; assisted migration
Mussell/shad hatcheries
Tipping points
Considerations
What are our goals?
How do we measure and monitor to evaluate
whether or not we are accomplishing our goals?
What inputs are needed to build better models for
predicting anticipated changes?
What are the barriers to accomplishing goals?
How will climate change in the Delaware Estuary? How will changes impact key resources? What are our options for making them more resilient? What actions are recommended to protect them? What if we don’t take action?
3 case
studies
PDE Climate Case Studies
In the Watershed
Water Quality
Improvement
Forest Protection
Stormater
Management
Green Infrastructure
Flow Management
Infrastructure
Updates
2000 2100
25% Loss
of tidal
wetlands!
In the Marshes
• Assessed condition of 268 points since 2010
• Comparative data analyses and management recommendations
• Studying ecosystem services associated with salt marshes
• Long-term monitoring stations (right)
• Devising new tactics to boost coastal wetland resilience
Mid Atlantic Coastal Wetland
Assessment
Living Shorelines
Coastal Wetlands for Shoreline Defense
Elevation Capital Layer
2020
2050
2035
2025
Hybrid LS Bio LS Sediment
Strategic BMP Layer
“Marsh Futures”
In the River and Bay
Shell planting for Oysters
Propagate Mussels
Monitoring & Research
In Communities
Out of Harm’s Way Forum – August 2012
In Communities
Areas of Opportunity for
the Community and
Conservation
Organizations to Work
Together to Improve
Resilience with Green
Infrastructure
BaySIPP The Bayshore Sustainable Infrastructure Planning Project
THANKS!
http://www.delawareestuary.org/Wetlands
http://www.delawareestuary.org/Climate-preparedness-0
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