Chinese households are outpacing the population by three-to-four times.

Jianguo (Jack) Liu, who directs the Center for Systems Integration and Sustainability at Michigan State University, has been tracking an interesting driver of carbon emissions in China: the explosion of households.

Speaking at the Society of Environmental Journalists‘ annual conference at the University of Montana, Liu said the number of households in China has been growing three-to-four times as fast as the population, which, in turn, is fueling a domestic boom in energy-intensive consumer goods, such as autos, air conditioners and major appliances (though one third of China’s carbon emissions are still due to products made for the export market, with the largest share bound for the US).

In a 2003 paper published in the journal Nature, Liu and his three co-authors concluded that:

“Rapid increase in household numbers, often manifested as urban sprawl, and resultant higher per capita resource consumption in smaller households, pose serious challenges to biodiversity conservation.”

Liu says that since that paper was published, households in China have continued to burgeon. Economic growth, urbanization and increased social mobility are driving two main trends behind the boom, he said: a drop in the number of multi-generation households, and the rising divorce rate.

According to a recent article in the Times of India, divorces in China have been rising steadily since 2003. The report cited a tally from the Chinese Ministry of Civil Affairs that counted 2.47 million divorces in 2009 alone. That’s about double the number in the US but with its vastly larger population, China’s divorce rate remains much lower than in most developed countries. Just under half of US marriages end in divorce.

Similarly, Liu said that while China has leapfrogged the US as the world’s biggest emitter of total greenhouse gases, it ranks only 16th in emissions per capita, about a quarter of the US, which retains its distinction as number one, per capita.

In a run-up to the next major round of UN climate talks in Mexico next month, recent meetings in Tianjin, China, turned contentious with US and Chinese negotiators accusing each other of inaction on their own emissions reductions. Congress has yet to pass a climate policy for the US. Meanwhile, China’s government has taken a creative approach to reducing its carbon footprint, with a promise to reduce the “carbon intensity” of its economy 40-45% by 2020. The plan, which ties emission targets to GDP, is not a pledge to reduce emissions per se.