Energy and Emissions from U.S. Population Shifts and Implications for Regional GHG Mitigation Planning.

Living in different areas is associated with different impacts; the movement of people to and from those areas will affect energy use and emissions over the U.S. The emissions implications of state-to-state migration on household energy and GHG emissions are explored. Three million households move across state lines annually, and generally move from the North East to the South and West. Migrating households often move to states with different climates (thus different heating and cooling and needs), different fuel mixes, and different regional electricity grids, which leads them to experience changes in household emissions as a result of their move. Under current migration trends, the emissions increases of households moving from the Northeast to the South and Southwest are balanced by the emissions decreases of households moving to California and the Pacific Northwest. The net sum of emissions changes for migrating households is slightly positive but near zero; however, that net zero sum represents the balance of many emission changes. Planning for continued low carbon growth in low carbon regions or cities experiencing high growth rates driven by migration is essential in order to offset the moderate emissions increases experienced by households moving to high carbon regions.

Historical carbon footprinting and implications for sustainability planning: a case study of the Pittsburgh region.

This study estimates fossil-based CO(2) emissions and energy use from 1900-2000 for Allegheny County, PA. Total energy use and emissions increased from 1900 to 1970, reflecting the significant industrial, economic, and population growth that occurred in Allegheny County. From 1970 to 2000, Allegheny County experienced a 30% decrease in total emissions and energy use from peak values, primarily because of a decline in industrial activity (40% decrease in value added) and the loss of a quarter of its population. Despite these dramatic economic and demographic transitions, per capita emissions remained stable from 1970 to 2000, buoyed by relatively stable or slightly increasing emissions in the commercial and transportation sectors. Allegheny County's history suggests the scale of change needed to achieve local emissions reductions may be significant; given years of major technological, economic, and demographic changes, per capita emissions in 1940 were nearly the same in 2000. Most local governments are planning emissions reductions rates that exceed 1% per year, which deviate significantly from historical trends. Our results suggest additional resources and improved planning paradigms are likely necessary to achieve significant emissions reductions, especially for areas where emissions are still increasing.