The Mid-Atlantic Region and its climate: past, present, and future

The physical and human geographies and the historical climate of the Mid-Atlantic Region of the United States are described to provide a baseline for an ongoing assessment of likely climate change impacts in the region. This region consists of 358 counties intersecting part or all of 8 states and 4 physiographic zones. This geographic diversity provides different sets of options for societies to adapt to environmental changes. Since 1967, the region's human population has grown in both number (19%) and income (116%), and important local ecosystems are experiencing associated stresses. Since 1895, the region's climate has become slightly warmer (+0.5 degrees C) and significantly wetter (+10%), although the warming has abated recently. Projections indicate that these broad regional socio-economic, ecological and climatic trends should persist through the 21st century. The significance of these changes in society, ecosystems and climate are evaluated in the more detailed, sector-specific analyses in the subsequent articles of this Special.