China's coal-control program, funded by Natural Resources Defense Council, recently issued a report advising the government to limit its total annual consumption of coal to 2.72 billion tons of standard coal by 2020, and raise the percentage of non-fossil energy to 15.3. Furthermore, it says, the percentage of coal should be lowered by 57.3.

This is a welcome plan. And even though experts may disagree with the figures, the plan points to the inevitable trend of reducing the use of fossil fuels.

Challenges, however, remain. The first challenge is to strike the right balance between meeting society's need for energy and the country's plan to reduce the use of fossil fuels. The central heating systems in northeastern provinces are mainly responsible for the recent smog. But that doesn't mean the government should suspend the central heating system to fight pollution, because the cold would become unbearable for people in North China without central heating. Besides, even if the government took the bold decision to suspend central heating, people would use electric heaters, burn wood or coal, or use other mediums to keep their houses warm, which too would cause pollution.

Given these challenges, municipal governments have no option but to replace small boilers with bigger ones as early as possible.

The second, and perhaps more difficult, challenge is to persuade residents to pay for cleaner fuels, which will cost more, in order to enjoy cleaner air and blue skies. Many people in today's China would readily spend money to buy a new car or decorate their houses or offices but wouldn't agree to pay higher energy costs to get cleaner air. This makes the job of leaders more difficult because they need greater courage to popularize the use of cleaner energy.

How to solve these problems will be a test for the leadership. But it has to excel in this test, so that the skies are free of the depressing smoggy skies and people can breathe cleaner air.

The author is a researcher with the energy studies center of the National Development and Reform Commission. The article is an excerpt of his interview with China Daily's Zhang Zhouxiang.