In China, the potential impact of green construction is not limited to a single city. For the last two decades, rural residents have migrated to urban centers by the millions. According to BBC, China's cities should house roughly a billion urbanites by 2025 [source: Campanella]. Constructing homes and facilities to accommodate these massive populations is big business here: Each year, roughly half of the world's new buildings are fabricated in China [source: Larson]. Meanwhile, despite consuming less energy per person than North American counterparts, the country's sheer population makes it the biggest emitter of greenhouse gases on the planet [source: Bradsher].
China spends more money than any other country on green energy projects [source: Melik]. The government has launched a few initiatives to promote green building, including subsidies to purchase energy-efficient materials [source: Liu]. While the accuracy of the statistic is questionable, Chinese officials say that more than 95 percent of new buildings constructed in urban areas comply with the country's energy efficiency standards [source: Liu]. But the energy efficiency benefits of green building might be the only viable way to deal with its burgeoning urban population: More than a quarter of the country's energy consumption is linked to its buildings, a figure that is expected to increase 70 percent by 2020 [source: Larson].