Rising U.S. trade with countries like China has major consequences on greenhouse emissions. Carnegie Mellon University engineering researchers describe how the U.S. has reduced its increasing carbon emissions by importing more carbon-intensive goods from other countries. For example, the amount of CO2 emissions generated from making a computer in China could be up to three times higher than when the same computer is made in the U.S. The researchers estimate that CO2 emissions associated with imports rose from 12 percent of total U.S. emissions in 1997 to 22 percent in 2004--a substantial increase given that the U.S. already emits around 25 percent of the world's total global carbon dioxide.
Many researchers question how emissions associated with traded goods should be accounted for. "These emissions are only going to increase as the United States continues to consume more and more essential goods from outside its borders," says researcher H. Scott Matthews. Since the U.S. continues to import more goods from carbon-intensive trading partners, this trend is likely to continue in the short term. . . There we go again: buying our way to the end of the world, one DVD player at a time. --JULIA WHITTY