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May 13: Carnegie Mellon Unveils New Classroom Study Tracing Environmental And Social Footprint of Pittsburgh Region From 1900 to 2050


Chriss Swaney

Shilo Raube

Carnegie Mellon Unveils New Classroom Study Tracing Environmental
And Social Footprint of Pittsburgh Region From 1900 to 2050

PITTSBURGH—Carnegie Mellon University researchers and students have unveiled a new study that found Allegheny County has seen an almost 20 percent decrease in total energy consumption and a 33 percent decrease in total carbon dioxide emissions since 1970, solely due to the collapse of the iron and steel industry in the area.

The study was compiled by a team of 24 Carnegie Mellon students from the departments of Engineering and Public Policy (EPP) and Social and Decision Sciences (SDS) under the supervision of professors H. Scott Matthews and Paul Fischbeck. They developed an estimate of the county's energy consumption and carbon dioxide emissions for every decade from 1900 to 2000.

"We determined the environmental impact for four major energy use sectors for Allegheny County, including residential, commercial, industrial and transportation," said Matthews, an associate professor of civil and environmental engineering and EPP. "We found that per capita energy consumption in the county has risen over the century, but has remained roughly constant since 1970. We also found that from 1900 to 2000, per capita carbon dioxide emissions in Allegheny County have varied very little with 2000 values about equal to 1900."

When compared to other regions of the country, the county is one of a few that has already achieved significant reductions in carbon emissions over 50 years, but these reductions came at tremendous cost — the loss of hundreds of thousands jobs and an entire industry. During this time, residential, commercial and transportation emissions have increased, but much less than the huge industrial decrease. As other regions start to plan their reduction strategies, lessons learned from Pittsburgh serve as a strong reminder of the social costs of serious reduction.

Carnegie Mellon researchers also calculated what the county's carbon footprint would be in the future by modeling an increase in immigration to Pittsburgh, more "green power" and residential energy efficiency investments from Pennsylvania's Act 129 program (designed to reduce electricity usage by 1 percent in 2011).

"We found that it is very difficult to move the needle of Allegheny County's carbon emissions more than a few percentage points in either direction," said Fischbeck, a professor in SDS and EPP. "Whether our population increases about 10 percent by 2050, or we benefit from an increase to 20 percent green power, or we get $10 million in investments from Act 129, the estimated carbon emissions will not change very much for the county."

As part of the study, the students surveyed 280 county residents who were under 21 or over 60 years of age. The survey asked them to estimate the 1960 and 2060 values for various environmental and social indicators for the county, such as population, number of cars and carbon emissions. While the two groups generally estimated correct values, some interesting discrepancies were found.

"One intriguing finding from our survey is that folks younger than 21 think that carbon dioxide emissions have increased over the last 50 years, and will continue to increase in the future, while participants older than 60 (correctly) estimated that emissions have been decreasing, and will continue to decrease," Matthews said. "We think the survey yields some interesting information for the county's policy makers because it represents an astute older population who know how the county has changed and predict a low-carbon, stable future, while the younger generation predicts much higher growth for the county, and in turn more emissions."