By Ann Fisher

The Mid-Atlantic Regional Assessment (MARA) report, Preparing for a Changing Climate: Mid-Atlantic Overview was released in March. More than 35 researchers at Penn State, other universities, the private sector, and government have contributed to the MARA. In addition to partnering with EPA's Mid-Atlantic Integrated Assessment Program (MAIA), as well as EPA's Region 3 Office, the assessment has been a stakeholder-oriented process, actively engaging an Advisory Committee of over 90 members from the private and public sectors. Their input, along with extensive peer review, were part of our efforts to ensure that the assessment would provide timely and useful information to a broad range of stakeholders in the region.
 
We identified potential positive and negative impacts of climate change and variability across the Mid-Atlantic Region, focusing on agriculture, forests, fresh water quantity and quality, coastal zones, ecosystems, and human health. Table 1 summarizes the impacts from climate change that might occur in the MAR by the year 2100. Because of large uncertainties about projecting changes in the region's climate, economy and ecosystems, we put the impacts in categories according to their likelihood. The size of an arrow indicates the impact's expected magnitude in relative terms.

We conclude that if the regional climate becomes generally warmer and wetter, as Figure 1 shows it is projected to do, ecosystems and biodiversity will be adversely affected. However, the region's diverse and highly integrated economy will offset some detrimental effects. The vulnerability of the region's people and other resources to major climate-induced impacts may be reduced because agriculture is declining in the Mid-Atlantic Region (MAR) as elsewhere for general economic reasons, and because people have access to varied energy sources and food supplies, modern public health practices, and climate-controlled environments in homes and workplaces.
 

Ecological impacts are expected to be most evident in the region's estuaries and coastal zones. Climate change may lead to a less diverse mix of trees and/or wildlife. Sixty-five percent of the Mid-Atlantic is covered by forests, and climate change may reduce the dominance of northern hardwoods and result in a different (possibly less diverse) mix of tree species. This could change the types of habitat available for wildlife and affect the profitability of the timber and pulpwood industries. The effects on freshwater fisheries will be both negative and positive: There will be less habitat for cold water species such as trout but more habitat for warm water species such as bass. Overall biodiversity could decrease if plants and animals are unable to migrate in pace with climate change, especially where they face migration barriers (such as sea walls and cities) and competition from invasive species.

The impacts of climate change are expected to be uneven across peoples and places. For example: Farmers who grow soybeans and tobacco, and possibly corn and tree fruits, are likely to have higher productivity, but tobacco will be less competitive. The potential for more very hot weather could increase heat stress for the very old and the very young and for people with less access to air conditioning and health care. Continued sea-level rise will increase erosion, salt water intrusion into public and private drinking water supplies and storm damage to coastal structures, wetlands and estuaries.

The report calls for measures to improve the region's resilience to climate change and variability and to provide benefits regardless of climate change. Examples include flood and drought management, watershed-based water quality protection and methods to deter development of vulnerable or sensitive ecological areas, such as flood plains and coastal zones. These actions would benefit the region now. Despite these suggestions, concerns remain. For example, the costs and effectiveness of adaptive responses to climate change are not known, and the availability of financial resources for adaptation is uncertain -- showing the need for additional research. In addition, climate change is likely to cause permanent alterations in some aspects of the region's ecosystem structures and functions.

For more information about the MARA:

See http://www.essc.psu.edu/. The report can be downloaded from this site or obtained from Ann Fisher, AERS, PSU, 107 Armsby Building, University Park, PA 16802, 814-865-4143, fisherann@psu.edu.