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.

Primary and embedded steel imports to the U.S.: implications for the design of border tax adjustments.

Carbon Border Tax Adjustments (BTAs) are a politically popular strategy for avoiding competitive disadvantage problems when a country implements a unilateral climate change policy. A BTA taxes carbon embodied in imported goods in order to protect domestic industry and motivate other countries to implement climate change policy. To estimate the effectiveness of a BTA, is it is necessary to know which products are covered, where they were originally produced and ultimately exported from, and how the covered amount compares to total production in foreign countries. Using a scrap-adjusted, mixed-unit input-output model in conjunction with a multiregional input-output model, this analysis evaluates the effectiveness of BTAs for the case study of U.S. steel imports. Most imported steel by mass is embedded in finished products (60%), and 30% of that steel is produced in a different country than the one from which the final good is exported. Given the magnitudes involved and complexities of global supply chains, a BTA that protects domestic industry will be a challenge to implement. We propose a logistically feasible BTA structure that minimizes the information burden while still accounting for these complexities. However, the amount of steel imported to the U.S. is negligible (5%) compared to foreign production in BTA-eligible countries and is unlikely to motivate affected countries to impose an emissions reduction policy.