Has China overtaken the United States in global warming?

Dear EarthTalk: I understand that China is about to overtake the United States as the world’s largest global warming polluter. What is China doing to address this issue as well as its other environmental impacts as such a populous nation?

Sophie N.

Andover, Mass.

Actually, China passed the United States as the world’s leading greenhouse gas emitter back in 2006 and today produces some 17 percent of the world’s total carbon dioxide output. According to the China Daily news service, air and water pollution, combined with widespread use of food additives and pesticides, make cancer the top killer in China. Meanwhile, World Bank data show that, based on the European Union’s air quality standards, only 1 percent of the country’s 560 million urban inhabitants breathe air deemed safe.

But many Chinese insist that all this environmental trouble is part of the cost of developing into a world superpower, and government leaders there are hesitant to impose restrictions on economic development.

Nevertheless, the Chinese are starting to take action. In December 2009 at the Copenhagen global climate talks, China announced plans to slow greenhouse gas emission increases relative to economic growth by 40 to 50 percent between 2005 and 2020 and use renewable fuels for 15 percent of its energy. China also committed to increasing forest cover by 40 million hectares by 2020 (forests absorb carbon dioxide).

But even with such measures, analysts say China’s carbon dioxide output will still increase a staggering 90 percent in the next decade, assuming 8 percent economic growth. While international negotiators were pleased to finally secure a commitment from the Chinese, it was a far cry from the fast and binding emissions cuts many scientists say are necessary to stave off potentially cataclysmic climate change.

Regarding other pollution, China is a signatory to the Stockholm Convention, which governs the control and phase-out of major persistent organic pollutants (POPs), including many pesticides, PCBs and other chemicals. China has committed to eliminating the production, import and use of pollutants covered under the treaty and will establish an inventory of POP-contaminated sites and remediation plans by 2015.

Other green strides China has made include 2008’s nationwide ban on plastic shopping bags. Before the ban, China was using 37 million barrels of crude oil annually to make the bags that would no doubt come back to haunt people, wildlife, land and water bodies as litter. China has also signed on to an international effort sponsored by the United Nations and the Global Environment Facility to phase out incandescent lightbulbs over the next decade in favor of more efficient varieties. China makes 70 percent of the world’s supply of lightbulbs, so the switch could have a big impact on energy usage for lighting around the world.

China now produces more solar panels and wind turbines than any other country.

And the Chinese government recently committed $216 billion in subsidies to further develop the nation’s green technology sector. A recent report by the nonprofit Pew Environment Group found that in 2009 China spent two times as much as the United States to fund so-called “green markets� and close to 50 percent of world expenditures overall.