Last year, China overtook the U.S. to become the world's largest emitter of carbon dioxide. And China is worried.
The government has set ambitious goals for reducing emissions and increasing energy efficiency by 2010.
One way China is trying to reach those goals is by focusing on buildings. The U.S.-based, nonprofit Natural Resources Defense Council estimates the country expends nearly half its total energy output on buildings: through manufacturing and transportation of materials, construction, then heating and cooling.
A nine-story, modern-looking office building in Beijing provides one example of how the government is tackling the problem.
China's Ministry of Science and Technology built it a few years ago, in collaboration with the U.S. Department of Energy and the defense council.
In 2005, the structure became China's first to get gold-level certification from the Leadership in Energy and Environmental Design rating system, recognized internationally as a standard of excellence.
A Model of Efficiency
Yang Guoxiong is one of the brains behind the building. On a tour, he points out features such as double-paned, argon-filled windows that reduce heating and air-conditioning costs by limiting the transfer of heat through glass, lights that turn on automatically when it's too dark to read and elevators that sense the passenger load and adjust energy use accordingly.
The roof has solar panels and rainwater collection tanks. But it's a serene spot, with seating areas in a garden of grass, trees and shrubs — grown on a shallow bed of volcanic ash that is lighter and less water-dependent than traditional soil.
"When this building went up, the neighborhood lost green space. So we're returning that bit of green with this roof garden. Moreover, the garden helps insulate the building," Yang says.
Yang is proud that the entire structure cost less than the average government building in Beijing.
The reason? More than 90 percent of the technology used was made in China. Importing hundreds of windows from overseas, for instance, would undercut energy savings and add additional costs and greenhouse gas emissions.
Falling Short of Goal
China's goal is to make all new buildings 50 percent more efficient by 2010. China's state media recently reported, however, that only half are meeting those standards.
From the rooftop, the challenge and the stakes are in plain view. Construction cranes reach skyward in every direction. New skyscrapers will soon sprout in their place.
All this steel, concrete and glass underscore China's enormous appetite for energy.
It's clear that this rapidly modernizing country has learned much about conservation. People are taking the challenge seriously — the showcase "green" office building is evidence of that.
But if China hopes to meet its efficiency goals, that showcase must become more of a standard.
Alex Wang, director of the China environmental law project for NRDC, says anyone working on climate issues in the country has reason to be optimistic. At the same time, he says the challenges China faces are unlike anything in its past.