The Implications of Climate Change for the Chesapeake Bay
Protecting the Bay Has To Be Someone’s Job
SOURCE: AP/Roberto Borea
Climate change will alter the Chesapeake Bay in ways that undermine important assumptions about resource management and restoration. Public agencies involved in bay protection do not need to wait for new authorities to address these issues.
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Climate change and the Chesapeake Bay have a lot in common. After decades of research and innumerable assessments, both are ready—past ready—for definitive action. They both reflect a voluminous history of scientific research that, unfortunately, has not yet been applied at scales sufficient to address the magnitude of the respective challenges. In the climate research community, it is old news to learn that the Earth’s climate is changing and that human activity is a dominant driver. In 2007, the U.S. Supreme Court held that the “harms associated with climate change are serious and well recognized,” and the Court required the Environmental Protection Agency to review its rationale for not regulating global warming pollution under its existing authorities. In the Chesapeake Bay, it is equally clear that human activity is smothering one of the nation’s finest estuaries in nutrient and sediment pollution. Again in this case, a lack of effective action has recently compelled the Chesapeake Bay Foundation and other advocates to file suit in federal court to force the EPA to fulfill its existing obligations to restore the Bay so that it can be removed from the agency’s list impaired waters. The similarities between these cases as matters of law and policy are important, but these issues also have critical physical connections.
Climate change is likely to alter physical and biological processes in the Chesapeake Bay in ways that undermine important assumptions about resource management and restoration. And as the Bay Foundation’s recent lawsuit underscores, public agencies involved in Bay protection and restoration do not need to wait for new authorities to address these issues. In fact, their existing responsibilities to restore the Bay require them to consider the implications of climate change and, when necessary, take action to ensure success under changing climatic conditions. This simple but profound reality has implications far beyond the Bay, as resource managers recognize that the effects of climate change are relevant to a wide range of decisions and that they are empowered and required to act under their existing authorities.
These are just a few of the implications of a new report on the impact of climate change on the Chesapeake Bay from the Bay Program’s Scientific and Technical Advisory Committee. The STAC is an independent body that provides impartial advice and guidance to the Bay Program, a regional partnership that has worked since 1983 to restore the watershed. The report concludes that climate change is more than a future threat to the Bay—it is an issue with immediate consequences for today’s restoration and protection decisions. Climate change alters historical trends in information upon which agencies base management decisions and transforms the environmental conditions for which existing restoration projects were designed.
The scientific literature clearly suggests that climate change is likely to bring warmer air and water temperatures to the region, accelerate sea level rise, and potentially change precipitation patterns. These changes are likely to exacerbate current stresses on the Bay ecosystem and complicate restoration efforts. For example, a changing climate is likely to:
- Alter the flow of pollutants into the Bay and their impact on water quality and living resources, including exacerbating the duration and severity of dangerous low oxygen conditions
- Create new requirements for environmental monitoring programs tracking the health of the Bay, including the ability to attribute changes in conditions between regional climate change and local management action
- Alter the effectiveness of critical restoration strategies, such as large-scale planting of submerged aquatic vegetation or the performance of water quality best management practices
- Undermine assumptions used in watershed modeling, such as the historical meteorological time series used to develop pollutant allocations for Total Maximum Daily Load regulations
The STAC study clearly indicates that these are not speculative connections. Rather, these are reasonably foreseeable outcomes based on a substantial foundation of scientific research, and they should be considered in decision making. The information compiled in the report makes it clear that the Bay Program and its state and local partners can and should take action to anticipate and adapt to changing conditions.
Figure 1. Observed changes in Chesapeake Bay surface water temperature from 1935 through 2007. The sampling points include the University of Maryland’s Chesapeake Bay Laboratory (CLB Pier) and the Virginia Institute of Marine Science (VIMS Pier). See the full report, Climate Change and the Chesapeake Bay: State-of-the-Science Review and Recommendations, for more information.It is essential to recognize that the need to respond effectively to changing conditions is not a new requirement—it is an existing responsibility based on the Bay Program’s mandates and authorities. This may seem premature to those who perceive climate change as a slow-moving, chronic problem. However, climate change has a variety of immediate implications.
Many, if not most, watershed management decisions are primarily based on historic climatic information, and changing conditions can undermine projects premised on past data. For example, the ability of surface waters to dilute pollutants is typically based on a distribution of flow rates—low flows are able to handle lower inputs of pollution before they are degraded below acceptable levels. The frequency and severity of low flow conditions is essential to setting acceptable pollutant discharge levels, such as those required to issue permits under the National Pollution Discharge Elimination System or Total Maximum Daily Load regulations. Changes in temperature and precipitation regimes will mean that load allocations based on observations over the last century may not meet regulatory standards under future conditions. The scientific literature is clear that a continuation of past climatic trends is one of the least likely outcomes, and, consequently, it is not acceptable to use this information as the primary basis for important management decisions.
Moreover, watershed managers plan many restoration measures for multi-decadal performance periods—they must function long into the period when climatic conditions are expected to be significantly different from those used in their design. For example, restoration strategies such as shoreline management or the design of urban stormwater systems are often literally “set in stone” (or concrete) and clearly intended to perform far into the next century. In fact, these strategies will need to perform for decades under conditions that are likely to be significantly different from those experienced in the recent past. For these long-term investments, climate change is an issue of immediate concern. Given the weight of scientific information about plausible future conditions, the failure to design and build projects without consideration for the types of conditions reasonably anticipated over a project’s design lifetime is unacceptable. It should also lead one to question what kind of design represents a reasonable professional standard of care. Just how much information do we need before consideration for rising sea levels becomes standard practice for coastal projects?
Climate change also has immediate implications beyond brick and mortar decisions. It is also immediately relevant to those monitoring the success (or failure) of Bay-wide restoration efforts. Today’s Bay monitoring system is nominally designed to detect trends in a wide variety of water quality and living resource metrics. Climate change creates a new requirement for the existing monitoring system: it must allow managers to differentiate between climate and non-climate-driven changes. It is essential that managers can understand the causes of future changes in the health of the Bay. The lack of this kind of information can allow scofflaws to argue that further degradation is due to climate change. Alternatively, it can allow for overly optimistic assessments of restoration efforts if climate change contributes to improved conditions. Either way, the scientific community can and should help create a monitoring system that has sufficient statistical power to differentiate between climatic and non-climatic drivers of change through the selection of indicators and the spatial and temporal selection of sampling sites.
EPA’s Chesapeake Bay program must catalyze many of these necessary changes, and the STAC report concluded with specific recommendations:
- Create a high-level climate change champion charged with identifying opportunities to address climate change within existing authorities and existing resources
- Develop and deploy new strategies to accelerate consideration of climate change in public and private sector decision making
- Prioritize and aggressively pursue targeted research and development to address specific implementation issues and strengthen the foundation of knowledge about the impact of climate change on the Bay
In other words, it is essential for climate change to be someone’s job. This is not a job for an intern or a fellow. Rather, it is a permanent position for a skilled and experienced professional who is empowered to use existing authorities and resources to anticipate and prepare for changing climatic conditions. Creating and staffing this position with a capable individual is a key indicator that the Bay Program and its partners are beginning to take this issue seriously. With this person in place, the Bay Program can begin to work with the STAC and stakeholders to prioritize the development of strategies to help protect and restore the Bay under changing conditions. At times, this will require focused research and development, and the Bay Program should help ensure that needs are clearly communicated and that resources are made available to support the work that needs to be done.
The challenges of climate change for the Chesapeake Bay are important and, in some cases, urgent. However, they are not unique, and they provide important lessons for any natural resource program guided by responsibilities under the federal Clean Water Act or other environmental legislation. Fundamentally, these policies create the responsibility to protect and restore natural resources. Given current scientific understandings, carrying out these existing responsibilities requires considering the consequences of changing climatic conditions. It is not acceptable to continue policies and programs based on assumptions that future conditions will mirror those of the past. It is necessary—not optional, not negotiable—for policymakers, regulators, and managers to use the best available information to anticipate and prepare for future conditions. Attention to these assumptions will help motivate the development of new strategies and approaches for addressing future conditions. This will ultimately help fulfill existing commitments to protect, and when necessary, restore air, water, and biological resources.
Dr. Christopher R. Pyke is the Director of Climate Change Services for CTG Energetics, Inc., a research fellow at the Virginia Institute of Marine Science, and a member of the Scientific and Technical Advisory Committee for the U.S. EPA’s Chesapeake Bay Program.
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