Last month was the first time in history that China reported higher total exports than the U.S.

China’s State Statistical Bureau reported total exports in July of US$80.34 billion, nudging ahead of the U.S. ($80.31 billion) as the world’s biggest exporter of goods and services. Of course, China’s gross national income (US$7.6 trillion in 2005) is still only 65% of the US (US$11.7 trillion), but China’s economy has been growing three times faster over the past five years (9.4% annually versus 3.2%).

As China’s export-led economy grows, so does its environmental footprint. Total carbon dioxide emissions in China in 2003 were 3.5 billion tonnes, 60% of the U.S. total in the same year. But between 1990 and 2002, China’s emissions jumped 46% — an average growth rate of 3.2% — while U.S. total emissions grew at a more modest (but still horrifying) rate of 1.5% per year over the same period.

If both countries’ carbon emissions were to continue to grow at a constant rate (and we may be beyond help if they do), China would catch up with the U.S. in carbon emissions within 29 years. At that time, the two countries’ combined emissions would have nearly tripled over 2002 levels, reaching 19.7 billion tonnes.

I’d like to say good sense has to prevail and none of this could really happen, but until some sort of massive catastrophe or global economic crisis occurs, there are no compelling reasons why it can’t happen. Along the way, U.S. energy profligacy in the past (and today) will continue to haunt us, and the rest of the world.

China can accurately claim that its carbon dioxide emissions per capita, 2.7 tonnes in 2002, are only 13% the current U.S. level of 20.2 tonnes per person.

If China’s per capita carbon emissions in 2035 actually reached the U.S. 2002 per capita level, then its total emissions would exceed 34 billion tonnes, 40% more than the entire world’s carbon dioxide emissions today. (This assumes annual population growth in China will slow to about 0.6% between now and 2035.)

What we need are alternatives to fossil fuels that could be used at scale.

Have I ruined your day? Make mine by pointing out where any of this is wrong.

(Other statistical data from the World Bank’s World Development Indicators 2006.)