- Sea level along coastlines in the Northeast has risen approximately one foot since 1900—a rate that exceeds the global average. Due to local land subsidence in the region, the rate of sea level rise over the next century is expected to continue exceeding global levels.
- The Northeast has seen a greater increase in extreme precipitation than any other region in the United States: the amount of precipitation falling in very heavy events between 1958 and 2010 increased by more than 70 percent. The frequency of heavy downpours is projected to continue increasing as the century progresses.
- The frequency, intensity, and duration of heat waves in the region is expected to increase through the next century, while the frequency, intensity, and duration of cold air outbreaks is expected to decrease.
- Climate change impacts in the Northeast—including coastal and riverine flooding and heat waves—will challenge its environmental, social, and economic systems, increasing the vulnerability of its residents, especially its most disadvantaged populations.
- Public and private infrastructure in the Northeast—buildings, roads, rail lines, airport facilities, and ports—will be increasingly compromised by climate-related hazards over the next century, as will agriculture, fisheries, and ecosystems.
- Climate change risks are increasingly being incorporated into state and municipal planning processes; however, implementation of adaptation and resilience-building measures is just beginning.
Sixty-four million people live in the Northeast, densely clustered in some of the most populated metropolitan areas of the United States, including New York City, Philadelphia, Washington, D.C., and Boston. Indeed, the high-density urban coastal corridor between Washington, D.C. and Boston is one of the most developed environments in the world. The region boasts one of the world's leading financial centers as well as the nation's capital, and it has a rich cultural history that predates early European settlement.
In contrast, the region also includes large expanses of sparsely populated but ecologically and agriculturally important areas. The regional landscape is dominated by forest, but it also includes grasslands and extensive marine and estuarine habitats—salt marshes, beach dune and barrier island systems, and fresh and brackish tidal marshes. The Northeast encompasses several major watersheds that empty into the Atlantic Ocean, and the North Atlantic Flyway and feeding grounds for the Right Whale and seabirds are strategic habitats identified as highest priority for conservation.
The economy in the Northeast is diverse, ranging from dairy farms to forestry, and includes biotech, education, health care, fish processing, marine construction, tourism, finance, transportation, and government.
A region in the midst of change
Over the past three decades, there has been significant population movement in the Northeast towards the coastline. Working waterfronts are part of the economic engine driving coastal redevelopment. Nearly five percent of this region has seen significant change to its land cover—increases in paved surfaces, and reductions and shifts in trees, forests, grasses, and wetlands—between 1996 and 2011.
A critical issue for the Northeast is addressing its aging infrastructure: roads, bridges, railroad lines, water and wastewater pipelines, culverts, and electrical power networks. The region has the oldest industry and building inventory in the United States, much of which was built along the coast and in estuaries—both of which are highly vulnerable to flooding.
The region's climate is also changing. Recent State of the Climate reports point out the likely impacts of a changing climate on both human and natural resources, which are threatened by rising temperatures, changing precipitation patterns, and a warming ocean, especially in the Gulf of Maine. The stretch of coastline from the tip of the Delmarva Peninsula in Virginia to the elbow of Cape Cod in Massachusetts is experiencing the greatest increase in sea level rise rate globally: 2 to 3.7 mm per year—more than three times the global average.
Temperatures in the Northeast rose by almost 2°F between 1895 and 2011, and models predict that the region could see a warming of 4.5°F to 10°F by the 2080s (assuming continued increasing emissions). Regional precipitation increased by approximately five inches, or more than 10 percent, during the same period. Seasonal drought risk in summer and fall is also projected to increase over the next century due to warming temperatures and earlier snowmelt.
The Northeast has seen a greater recent increase in extreme precipitation than any other region in the United States—the region experienced more than a 70 percent increase in the amount of precipitation falling in "very heavy events" (defined as the heaviest one percent of all daily events) between 1958 and 2010. The frequency of these heavy downpours is projected to continue to increase over the remainder of the century.
More frequent, intense, and longer heat waves are also projected to increase over the next century in the Northeast, which will affect the region's vulnerable populations as well as its infrastructure, agriculture, and ecosystems. However, climate models indicate that the frequency, intensity, and duration of cold air outbreaks will decrease over the same period.
The preceding text is excerpted and abridged from the report Climate Change Impacts in the United States: The Third National Climate Assessment (Chapter 16: Northeast).
Building resilience is critical
Federal agencies, through regional groups such as the New England Federal Partners and the Federal Climate Partners for the Mid-Atlantic, are addressing mounting threats on the prosperity and resilience of the Northeast by examining many sectors, including food and water security, infrastructure, and public health and safety.
To learn more about the impacts of climate change and variability and building climate resilience in the Northeast, visit these pages: