Climate Change:
Wetlands and
coastal zones
Impacts and
adaptations
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This Photo by Unknown author is licensed under CC BY-SA-NC.
What are wetlands?
Ecological
importance
• A wetland is an area with a water
table, at, near or above the land
surface either seasonally or
permanently throughout the year.
• Wetlands exist globally in every
country (except Antarctica) and in
all different types of climates.
Depending on different definitions
and estimates, they cover only
about 5–8% of the world’s land
surface, but comprise 20–30% of
the world’s carbon pool.
• Wetlands are ecosystems that are vital both for humankind and nature. They are
commonly the most valuable ecosystems in a landscape providing many
beneficial ecosystem services.
• Among all wetland services, water purification, flood control and climate change
mitigation are the most important services for the human communities
This Photo by Unknown author is licensed under CC BY.
Wetland values
in land scape
Food: fish production, wildlife and
fruits
Provisioning
Freshwater: domestic water
retention and storage, agricultural
use and industrial Use
Fuel and fiber: log production,
wood for fuel, fodder and peat
Regulation
• Regulation of climate: greenhouse gas
sink, altering local and regional
temperature and precipitation retention
• Regulation of water hydrology: recharge
of groundwater
• Wastewater treatment and water
purification: excess nutrient and
pollutant removal as well as process of
retention and recovery
• Regulation of erosion: soil and sediment
retention.
Cultural
Inspirational and spiritual:
source for inspiration and
spiritual functions for
various cultures
Aesthetic: source of beauty
and aesthetic values with
respect to wetland
characteristics
Educational: source for
formal and informal training
and education
Genetic material:
ornamental species and
genes for pathogen plant
resistance
Supporting
Soil formation: accumulation of organic
matter and retention of sediment
Cycling of nutrients: nutrient
acquisition, storage, recycling and
processing
Regulation of natural hazards:
controlling of floods and storm
protection - Pollination: habitat for
pollinators.
benefits of
wetlands
• Improved Water Quality
• Wetlands can intercept runoff from surfaces
prior to reaching open water and remove
pollutants through physical, chemical, and
biological processes
• Erosion Control
• Flood Abatement
• Habitat Enhancement
• Water Supply
• Recreation
• Partnerships
• Education
Potential impacts to wetlands
• Since wetlands are often located in a transition zone between
an aquatic and a terrestrial ecosystem, their hydrological
fluctuation is inevitable.
• Climate change can affect wetlands by direct and indirect
effects of rising temperature, changes in rainfall intensity and
frequency, extreme climatic events such as drought, flooding
and the frequency of storms.
• hydrology and rising temperature can change the
biogeochemistry and function of the wetland to the degree
that some important services might be turned into
disservices.
Cont.
• This means that they will no longer provide a
water purification service.
• A higher rate of decomposition than production
(photosynthesis) in a wetland as a result of
climate change might result in a shift from a
sink to a source of carbon.
• with warmer conditions, more nitrous oxide
emissions from wetlands might happen due to
higher microbial activity
• loss of soil moisture in drought conditions.
• Shifts in biological communities. Changes in both
temperature and hydro period can lead to alteration of plant
and animal community structure.
• Impacts to rare species. Because of their sensitivity to
ecosystem structure and conditions, these species may be
especially vulnerable to climate change impacts.
Wetlands and
adaptation to
climate
change
• Wetlands are generally considered as
resilient with new environmental regimes
that will exceed the resilience thresholds
of wetlands.
• The resilience of many wetlands and their
ability to adapt naturally is exceeded by
2100 by an unprecedented combination
of change in climate, associated
disturbances (e. g. flood in g, drought)
and other global change drivers.
• The overall impact of
climate change in
inland wetland ecosystems
will largely depend on the
rate and magnitude of
change in two critical
climate drivers:
• In addition, sea level and
storm surges will also be
important drivers in
coastal and lowlying wetlands
Adaptation to climate change
Wetlands provide ecosystem services that will contribute to our
ability to adapt to climate change. Three of the most commonly
cited wetland ecosystem services are:
• Their role in hydrological cycle
• Their ability to improve water quality
• The habitat they provide for fish, wildlife and native plants.
Wetlands in
the
hydrologic
cycle
• Climate change is expected to result in
changes to the hydrologic cycle including
altered precipitation and snow melt
patterns.
• Wetlands can offset changes in precipitation
and snow melt by storing water and
reducing the effects of drought and severe
storms.
• The cumulative presence of wetlands and
lakes in a watershed can reduce flood flows
during big storm events.
• Wetlands are also a source of surface and
groundwater recharge in drying landscapes.
They help keep waters flowing in streams,
which helps offset the effects of summer
droughts on fish and other species. Even a
small percent of peatland in a watershed can
produce up to half of the stream flow.
• Coastal wetlands can protect against storm
surges that can affect areas farther inland on
the coast than in the past because of higher
sea levels.
Wetlands and
water quality
• Climate change can increase storm
intensity, resulting in increased storm
water runoff, which
carries contaminants harmful to water
quality, fish, and other wildlife.
• Wetlands are often referred to as a
“kidney” in the landscape.
• Through cycles of wetting and drying,
combined with the bacteria and plants
that live in wetlands, they
can sequester, alter, and / or
assimilate contaminants such as excess
nutrients, heavy metals, and
petroleum products.
• Their role in water quality
management will contribute to our
ability to adapt to climate change.
Wetlands and
habitat
Wetlands provide a refuge from
the effects of climate change.
Wetlands are among the most
productive ecosystems in the
world. They are used by more than
two-thirds of terrestrial vertebrate
species, including
• 65 percent of mammals and 72
percent of birds.
• They are also key habitats for fish
development and
amphibian reproduction
• Wetlands can reduce the effects
drought and heat have on wildlife
by providing a source of water or
moist, cool microclimates. As the
climate changes, wetlands also
provide a corridor or stepping stone
on the landscape that may help
species move to better areas.
• In coastal areas, eelgrass beds can
reduce the effects of ocean
acidification, resulting in areas that
may be able to support species that
have already been impacted by
changes in water chemistry.
Healthy wetlands
support mitigation
and adaptation to
climate change
• Wetlands sequester some
of the largest stores of
carbon on the planet, but
when disturbed
or warmed, they release
the three major heattrapping greenhouse gases
carbon dioxide, methane,
and nitrous oxide.
• Protecting wetlands from
human
disturbance therefore
helps to limit the increase
in greenhouse gases in the
atmosphere.
Wetlands
mitigate effects
of climate
change
• Coastal wetlands, undisturbed inland
wetlands, and lakebeds are important
carbon sinks.
• Coastal wetlands sequester carbon
efficiently and emit relatively little methane.
They are estimated to sequester twice as
much carbon in their soil than all tropical
forests.
• Older freshwater wetlands sequester more
carbon than they emit