LONDON – Just as rich nations have passed the responsibility for carbon dioxide emissions to the developing nations, so the rich provinces of China have exported the problem to the poorest regions, according to new research.

The world's biggest single emitter of the greenhouse gas – 10 billion tons in 2011 – has undertaken to reduce the "carbon intensity" of its economy. But, according to Klaus Hubacek of the University of Maryland and colleagues, the richest and most sophisticated regions of China – those with the most stringent and specific pollution abatement targets – are buying manufactured goods from places like Inner Mongolia, a poorer region where targets are less constraining.

"This is regrettable, because the cheapest and easiest reductions – the low-hanging fruit – are in the interior provinces, where modest technological improvements could make a huge difference in emissions," said Steven Davis of the University of California, Irvine, and one of the authors.

Tougher targets

"Richer areas have much tougher targets, so it's easier for them just to buy goods made elsewhere," Davis added. "A nationwide target that tracks emissions embodied in trade would go a long way towards solving the problem. But that's not what's happening."

Hubacek, Davis and six others report in the Proceedings of the National Academy of Sciences that they examined China's output and emissions in 2007 in 57 industry sectors across 26 provinces and four cities.

In that year, China's emissions totaled more than 7 billion tons, of which more than half came from fossil fuels burned to make goods and services that were consumed either in other parts of China, or beyond China's borders to 107 countries.

In effect, the authors provided a geography of China's internal trade. More than 75 percent of the emissions associated with the goods consumed in Beijing-Tianjin – one of the three most affluent regions – were pumped into the air in other provinces.

In 2009, at the United Nations climate conference in Copenhagen, China vowed to reduce the carbon dependence of its economy by lowering CO2 emissions per unit of gross domestic product from 2010 levels by 17 percent by 2015. This would be achieved by imposing 19 percent reductions in the affluent east coast provinces, and 10 percent in the less developed west, the country said.

Pushing factories east

The implication is that emissions-reducing policies tend to push factories and production into regions where costs are lower, and pollution standards less stringent.

"We must reduce CO2 emissions, not just outsource them," said Laixiang Sun of the University of Maryland and a study co-author. "Developed regions and countries need to take some responsibility, providing technology support or investment to promote cleaner, greener technology in less developed regions."

The results, the authors conclude, "demonstrate the economic interdependence of Chinese provinces, while also highlighting the enormous differences in wealth, economic structure, and fuel mix that drive imbalances in interprovincial trade and the emission embodied in trade."

This article originally appeared at The Daily Climate, the climate change news source published by Environmental Health Sciences, a nonprofit media company.