Have China's carbon emissions already peaked?
China is still the world's largest producer of greenhouse gas emissions 鈥斅爁or now. But the energy giant may have already hit its carbon dioxide emissions peak 16 years ahead of schedule, a potential spur for the United States to honor its own climate commitments.听
Humans' greenhouse gas output increased by about 0.5 percent in 2014, thanks to serious reductions from the world's largest carbon dioxide emitter. Climate scientists say that China鈥檚 carbon dioxide emissions may have peaked in 2014, the same year that President Xi Jinping promised President Obama a 2030 peak. , and coal consumption remained flat, while the economy continued to grow by seven percent.
"I'm of the opinion that this is a trend that will continue," Barbara Finamore, Asia director for the environmental-advocacy group National Resources Defense Council, tells Nature. "This is ."
Coal, the world鈥檚 cheapest and dirtiest energy source, accounted for almost 45 percent of the world鈥檚 energy-related carbon dioxide emissions in 2011. And in China, the world鈥檚 biggest CO2 emitter, coal accounts for聽聽of China's energy consumption.
Earlier studies may have overestimated China's coal use, helping the country meet its goals, but the government has also led efforts to limit nonrenewable energy and boost alternatives such as wind, solar, and nuclear power, strengthened in the country's聽.听
"China's international commitment to peak emissions 'around 2030' should be seen as a highly conservative upper limit from ," Fergus Green and Nicholas Stern wrote last month in the journal Climate Policy.
The Chinese government releases statistics on energy consumption and production, but , making outside estimates difficult. Some scientists say China has been underestimating its coal usage since 2000, burning up to than the government previously disclosed. 聽聽
But it is clear that China produces more climate change-causing gases than any other country. For carbon dioxide alone, the leading cause of climate change from energy consumption, China produces . The United States comes in second with 17 percent, followed by India and Russia with five percent each.听
While the recent reductions are great news for China, climate scientists also note the importance of China's success for encouraging change around the world 鈥撀爌articularly in the United States.听
"It would certainly blunt the argument made by those who say Washington should not make ambitious climate commitments because ," Edward Wong wrote in The New York Times. It is easy for the United States to point fingers at China鈥檚 10-point lead in overall emissions, but China also has a far larger population. If carbon dioxide emissions are looked at in terms of metric tons per person, far outweighs China's 6.52 metric tons person.
But China will have to address serious obstacles if 2014 is to remain its peak year. Energy use is expected to grow as urbanization climbs from 55 percent to its 2020 goal of 60 percent, and the country will have to decisively turn toward other non-coal sources of power.听
Xie Zhenhua, China's senior climate change deputy, has said that carbon emissions did not peak in 2014 and ,聽suggesting China may fully utilize its remaining coal-burning days right up until deadline.听
"I would be more confident to say that China has reached a plateau or period of low growth," Glen Peters, a scientist at the Center of International Climate and Environmental Research-Oslo, told The New York Times. "I think to say 'peak' is a little bold."聽
But climate scientists on both sides of the data 鈥撀爐he skeptics and the optimists 鈥撀燼gree that China is on track to reach its promised 2030 peak.听
