What are the potential impacts of climate change to estuaries and coastal areas?

Estuarine systems are particularly vulnerable to many of the projected effects of climate change, such as:

• Sea level rise
• Increased temperatures
• Changes in precipitation and storm intensity
• Ocean acidification

Examples of specific impacts that may occur in estuaries and other coastal areas include:

• salt-water intrusion into aquifers as the sea rises,
• flooding of coastal wetlands and marshes,
• changes to water availability and quality,
• changes in habitat and species distributions,
• lower oxygen levels in wetlands,
• ocean acidification (due to higher concentrations of carbon dioxide in the atmosphere), and
• a range of impacts from more severe coastal storms.

These impacts may occur in tandem with other existing stressors, such as coastal population growth, presenting new and different challenges to National Estuary Programs and coastal communities. 

See more examples of climate impacts in coastal areas.

What can be done to make estuaries climate ready?

Coastal resource managers can reduce risks and improve resiliency by:

• proactively identifying areas that are particularly vulnerable,
• monitoring for changes, and developing and
• implementing adaptation plans.

These adaptation plans may contain a wide range of adaptation actions that are designed to reduce impacts or exploit beneficial opportunities resulting from climate change.

Adaptation plans are linked to management goals, such as maintaining water quality of marshes and wetlands, protecting coastal development, preserving habitat, or controlling invasive species.

For example, if the management goal is to maintain wetlands, adaptation strategies might include:

• prohibiting the construction of bulkheads,
• establishing rolling easements, or
• incorporating wetland protection into the planning of new infrastructure.

If the goal is to maintain sediment transport, managers could:

• trap or add sand through beach nourishment,
• remove barriers to sediment deposition on wetlands (e.g., levees), or
• trap sand through the construction of groins.

Why should coastal resource managers focus on adaptation?

Reasons why coastal managers should focus their efforts on adapting to climate change include:

Vulnerability:

• Coastal zones are highly vulnerable to climate change.
• Climate-driven impacts will be further exacerbated by other human-induced pressures (IPCC 2007).

Timing:

• Coasts are already experiencing climate change impacts.
• The Earth is committed to additional impacts due to past and current greenhouse gas emissions. Adaptation planning is necessary to address these already unavoidable impacts.

Opportunity:

• Adaptation can help reduce the long-term costs of climate change impacts (IPCC 2007).
• See Adaptation Planning for the National Estuary Program.

References

IPCC, 2007: Climate Change 2007: Impacts, Adaptation and Vulnerability. Exit Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Parry, Martin L., Canziani, Osvaldo F., Palutikof, Jean P., van der Linden, Paul J., and Hanson, Clair E. (eds.)]. Cambridge University Press, Cambridge, United Kingdom, 1000 pp.