 China has responded with increasing environmental regulations and a build-up of pollutant treatment infrastructure which have caused improvements on some variables.As of 2013 Beijing, which lies in a topographic bowl, has significant industry, and heats with coal, is subject to air inversions resulting in extremely high levels of pollution in winter months.In response to an increasingly problematic air pollution problem, the Chinese government announced a five-year, US$277 billion plan to address the issue.