Wang Canfa, head of China University of Political Science and Law's environmental law institution Editor's note: During the two sessions, China Daily has collected questions foreign netizens care most about and solicited answers from experts, CPPCC National Committee members and NPC deputies.

Should the central government adopt stricter policies on polluting companies as well as provincial, city and county environmental authorities?

China has seen improvements in its air quality, but the changes have so far not been large enough to meet people's expectations. To make our skies blue again, China has introduced stricter air-pollution controls in recent years, including allowing environmental and judicial authorities to punish polluters.

Among the laws and regulations related to pollution control, the new judicial interpretation of environmental crimes, which took effect on Jan 1, is considered a powerful weapon.

The interpretation, designed by the Supreme People's Court and the Supreme People's Procuratorate, stipulated for the first time that falsifying environmental data is a criminal offense, which means serious offenders face a fine and three to seven years in prison. The move has deterred many companies from discharging excessive pollutants.

In addition, the central government conducts frequent environmental inspections, which pushes provincial, city and county policymakers to implement air-quality control measures.

Senior officials who fail in their duties are punished, such as with suspension, while local governments that fail to meet environmental targets face restrictions on getting approval for new construction projects.

I've found that the existing measures are working, as they show polluters the high cost of violating the law.

It will take time to make obvious improvements to the air quality, but China is marching quickly forward.