According to its authors, China is poised to become a renewable energy leader in the near future. But to what extent will this diminish China's problems?
"Reaching this milestone in such a short time would constitute a remarkable achievement with clear benefits for meeting China's energy needs and improving its energy security, while also reducing air pollution and lowering carbon emissions," the report says.
Others have contended, however, that despite renewable energy gains, China's overall demand for energy, carbon-emitting coal specifically, may balloon even beyond current expectations.
Predictions are piling up as China's energy appetite and carbon emissions increase at rapid rates. According to the International Energy Agency, global demand for energy could double by 2030, with China and India accounting for 45 percent of that growth. As the IEA notes, this will deepen China's reliance on energy imports and raise its level of carbon emissions. In per capita terms, China's emissions remain below those of the United States. Nonetheless, as urbanization draws more and more of China's 1.3 billion people to the cities -- where per capita energy use is three times that of rural inhabitants -- worry for the future mounts in China and abroad.
The good news, according to Worldwatch's report, is that the Chinese government is pushing renewable energy. In 2005 the National Peoples' Congress approved a Renewable Energy Law, and the government development plan released in September included the goal of supplying 15 percent of China's total energy with renewable sources by 2020.
"I don't think there's any doubt that that target will be reached," said Eric Martinot, visiting professor at Tshinghua University and co-author of the Worldwatch report. "I think it's conservative actually."
His evaluation is based on a "technology-by-technology" analysis of China's progress to date.
Current trends in wind power, for instance, suggest that China could exceed its 2010 target of 5 gigawatts of power capacity by 2 to 3 GW. And while Martinot expects the rate of installations to accelerate, even if "the same pace of installations continues, China would still reach the (30 GW) target by 2020."
Likewise, "I don't think there's any question that the solar hot water target will be met," he said.
China is already the world's largest market for solar hot water, and it is estimated that one-third of Chinese households could be using solar hot water between 2020 and 2030.
Similar scrutiny of the biomass and biofuels industries led Martinot and co-author Li Junfeng to the conclusion that not only will renewable energy sources supply 15 percent of China's total energy by 2020, but that they should constitute 30 percent of the total by 2050. Martinot said it would be reasonable to expect 30 percent as early as 2035.
China's burgeoning leadership in renewable energy is not limited to consumption, but involves investment and production, too, Martinot said.
In 2006 China was the world's No. 2 investor in renewable energy, spending about $10 billion. Germany earned first place, while "the U.S. was a distant third with about $5 billion," he said.
While much of what China produces is absorbed by domestic demand, China is also contributing to the world energy market. Solar PV, still too expensive for China's home market, is one such example. The Worldwatch report notes that production capacity for solar PV could quadruple between 2006 and 2020.
"I think production of Solar PV will continue to grow very rapidly," said Martinot, and "if there's no domestic market for solar PV then it will all be exported."
Given China's fame for low-cost production, such exports could help reduce world renewable energy prices, according to the report. Chinese companies are already producing solar hot water heaters for one-fifth to one-eighth the price of those sold in the United States and Europe.
The Worldwatch report also suggests that China's renewable energy prowess might have a more direct benefit -- reducing the nation's carbon emissions. Of course, the significance of such a reduction depends on the overall growth rate of China's emissions, which some say could surpass expectations despite the surge of alternative energy sources.
While Martinot believes that "the growth in renewables will match or exceed the growth of energy," a report released by the Center for Strategic & International Studies in October casts doubt on that assertion.
The study contends that both China and international energy organizations have underestimated China's future energy needs. In the CSIS scenario, China's demand for coal and its level of carbon emissions in 2025 will exceed IEA and U.S. Energy Department predictions. It warns that Chinese carbon emissions could double those of the United States by that year.
This suggests "that worldwide efforts toward reducing global warming and greenhouse gas emissions will likely be overwhelmed by China if the country's current path of energy and development continues," says the study.
This sobering scenario takes the expansion of renewable, and other non-coal based energies into account, yet maintains that greater than expected demand will drive coal-based "electricity consumption upward at a rapid rate, one that cannot be matched by hydro, nuclear and renewables as a group."
For the CSIS authors, slower economic growth may be the only way to rein in China's voracious demand for energy and restrict its damaging environmental effects.