Yesterday a D.C. nonprofit, the Center for Global Development, released an inventory of the world’s power plants. Its nifty database shows that on a national level, China trails only the the U.S. in total emissions of greenhouse gases, and not by much.

This will disappoint the global warming proponents at the National Review, who have been predicting for months that China will surpass the traditional emissions champ — the United States — this year.

But both the scoffers on the right and the worriers on the left may be overlooking a central question, which was broached this Monday in a news story from The Wall Street Journal.

Simply put: a high percentage of Chinese emissions are produced in factories making products for buyers around the world. Shouldn’t that be considered in the emissions accounting?

The vast majority of the world’s MP3 players are made in China, where the main power source is coal. Manufacturing a single MP3 player releases about 17 pounds of planet-warming carbon dioxide into the atmosphere. iPods, along with thousands of other goods churned out by Chinese factories, from toys to rolled steel, pose a question that is becoming an issue in the climate-change debate. If a gadget is made in China by an American company and exported and used by consumers from Stockholm to São Paulo, Brazil, should the Chinese government be held responsible for the carbon released in manufacturing it?

The story hints at the complexity of fault-finding when it comes to emissions, which we as a nation and as a species have barely begun to unpack. Not only must we contend with the fact that carbon dioxide is indivisible — and equally warming no matter if it’s emitted in a Communist nation such as China, a capitalist nation such as the U.S., or a third-world nation such as India — but there is also what The Stern Review calls the "intergenerational" aspect of emissions. Carbon released today may have catastrophic effects thirty years from now, when the original emitters are long dead. Who will the children of today blame then?

But to continue with Jane Spencer’s thoughtful, probing story:

Roughly 23% of China’s emissions come from the production of goods that are shipped elsewhere, according to a recent report by the Tyndall Centre for Climate Change Research in Britain.

Some economists dismiss the argument and note that China happily benefits from the arrangement. "China loves being an exporter, so it’s ironic they would blame the U.S. for their exports," says Robert Stavins, a professor of business and government at Harvard University. "It’s called having your cake and eating it too."

At this point, the blame-the-buyer approach is more a negotiating tactic than a serious proposal for redrafting the global-emissions map. But as new studies and reams of data become available tallying embedded emissions, the research could influence the debate over what kind of emissions cuts various nations should be called on to make.

Interestingly, the facts compiled by the WSJ undercut the recent boast from the prez that the U.S. is the only industrialized nation to cut emissions last year.

Technically, carbon emissions in the U.S. have declined in recent years, a fact noted by President Bush. U.S. carbon emissions fell 1.3% in 2006. But a recent study by researchers at Carnegie Mellon University suggests the U.S. may be cutting its emissions by outsourcing more manufacturing.

As international trade has boomed over the past decade, the U.S. has begun importing dramatically more carbon-intensive products from its trading partners, according to the researchers. The study found that so-called embedded emissions in U.S. imports roughly doubled from 1997 to 2004. In 2004, the U.S. imported as much as 1.8 billion tons of CO2 embedded in products, the equivalent of 30% of the nation’s carbon output that year. Many of those goods are coming from China.

The news story goes on to argue that regardless of who is to blame for what is now known as "embedded emissions," the solution is the same: a tax on "carbon-intensive" goods such as iPods. As evidence, Spencer points to proposals from France and bills in Congress to tax energy-consumptive imports.

It should be noted that the WSJ has its own reasons to flatter China: Rupert Murdoch, soon to be the new owner of the paper, plans to launch new editions in developing markets such as China and India. "Somewhere between 50 and 100 million people a year are joining the world economy," he told a shareholder group. And earlier this year he was accused by a group of China-based reporters at the paper of "sacrificing journalistic integrity to satisfy personal and political aims."

But that doesn’t change the fact that everyone of us who owns an iPod or a similarly carbon-intensive product bears some responsibility for its manufacture and its emissions — even if it was made in China.