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Karen Polenske: Chinese Lessons

Brazil is hailed for its homegrown sugarcane-derived ethanol and its growing independence from foreign oil (see “Brazil’s Bounty,” Technology Review, July/August 2006). Meanwhile, China is decried for mining and burning its vast coal resources with little concern about environmental impact.

Karen R. Polenske, professor of regional political econo­my and planning, says that even though there are energy-use problems in China, the news isn’t all bad. Burning coal causes environmental and health problems, but while Brazil’s energy intensity–a measurement of energy used per unit of output, usually GDP–went up by 36 percent between 1980 and 2004, China’s fell by 61 percent.

In 1997, Polenske decided to investigate why. She focused on one of China’s most energy-intensive products: metallurgical coke, which looks like black lava rocks and is critical to steelmaking. Coke is made by burning coal at temperatures ranging from 900 to 1,400 °C, either in crude, highly polluting ovens or in new slot ovens that capture gaseous by-products. Her research has targeted Shanxi province, where 40 percent of the country’s coke is made.

What has she learned about why energy intensity is falling? “In China, we have shown very conclusively that it’s new technologies rather than change in industries,” she says. In 1978, China opened up to international trade and replaced 50-year-old Russian machinery. “The fact that they could import new technologies is what we think affected energy intensity,” Polenske says.

Polenske’s research is grounded in input-output analysis, a mathematical modeling method used in economics. “Input-output analysis looks at what all industries in a region produce and purchase,” she says. Simpler economic analyses take only an industry’s direct requirements into account: for example, iron and steel are directly required to make automobiles. “But iron and steel require iron ore, coke, coal,” she says. “And each of these have supply chains.” Indirect inputs, such as coal’s contribution to steelmaking, “often produce more pollution” than direct ones.

In China, people are starting to see the connection between coal and pollution, says Polenske, but most plant owners don’t have the money to replace their polluting machinery. However, the situation may improve soon. Polenske says foreign investors who have been pouring money into companies based in big cities like Beijing are redirecting their attention to industry in Shanxi as China’s demand for steel increases.

In the meantime, Polenske’s team has measured the concentration of fine particulates all around coke plants and in workers’ homes, to help demonstrate that pollution from coke production causes cancer. “Part of my desire is to get them to see what we in the U.S. are learning far too late–that these industries are highly polluting,” she says.

After years of research trips to China, Polenske is now embarking on a project to compare the country’s energy usage with that of Brazil and India, which also have major steel industries. Of the developing countries, China, Brazil, and India are the three biggest energy users, she notes. Her project will study the effects of policy on the adoption of new technologies. In Chinese industry, adoption of new technology is driven by the mandates of the central government; in Brazil and India, democratic republics, the picture is likely to be different.

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