Since 2013, China has made the important choice of emphasizing environmental protection and green development over a focus on raw GDP growth. Also, government institutions have been reformed to strengthen enforcement of environmental protection laws.

During a visit to Yucun village in Zhejiang province on March 30, President Xi Jinping said: "The environment itself means the economy. If you protect the environment, you will receive rewards from the environment."

And in his speech kicking off the International Horticultural Exposition in Beijing in April 2019, Xi said: "The development model of 'killing the hens for eggs' and 'draining the lake for fish' is at a dead end."

Environmental protection is linked with the broader economic strategy of restructuring industry toward higher value-added manufacturing and services, away from the old reliance on heavy industry, resource extraction and low-tech steel and coal production. Of course, there is sometimes a trade-off between jobs and the environment, but much evidence shows that shutting down inefficient highly polluting factories often clears the way for cleaner, more efficient and more profitable production.

New high-tech industries will not only produce higher-quality products demanded by China's growing middle-income group. The shift toward investment in environmental protection could also allow many Chinese companies to gain a first-mover advantage in many innovative products that will be needed to improve the environment worldwide. For example, China's sales of electric vehicles are about the same as the rest of the world combined and two-thirds of the world's solar panels are produced in China.

"The future will be illuminated by eco-friendly development that is in accordance with the rules of nature ... China's ecological civilization development is on a fast track. People will live in a better environment with blue skies, green mountains and clear water," Xi said."We should protect the ecological environment like protecting our eyes and value it in the same way we value our lives."

Strong enforcement of environmental regulations is key to bringing about the green economy.

In an interview with China Daily, Yang Dongning, a professor of economics at Peking University's Guanghua School of Management, said: "Previous policies with a green focus were not systematic or consistent. When the pollution issue became very prominent, there would be 'storming campaigns'. But since the central leadership with Xi Jinping as the core started in 2013 and the 13th Five-Year Plan (2016-20) was approved, regulation has been systematic, rather than abrupt. Environmental inspections combined with Party discipline have led to very significant results."

China has seen major improvements in environmental quality since 2013. The average PM 2.5 concentration, a measure of the most dangerous kind of air pollution, fell from 93.23 in January 2013 to 63.83 in the third quarter of 2018, according to an index compiled by the Asia Society. This is a fall of 35 percent. Water quality developed more slowly, but still improved 7 percent over the period.

I arrived in Beijing in January 2013, during the famous "airpocalypse" when the air quality index reached its worst point at 993, 40 times the level deemed safe by the World Health Organization. Anyone living in Beijing or in other Chinese cities can testify to the astonishingly rapid improvement in air quality since then.

Fang Li, CEO of World Resources Institute China, said in an interview with China Daily that her foreign colleagues wanted to know how China improved its environment so quickly. In a 2012 meeting, some said it would take 30 years to improve air quality, as it has in many countries. Fang was more optimistic and thought it would take 10 years－not anticipating the progress that would be possible in just five years.

She explained that two factors made China's rapid progress possible. First, much environmentally friendly technology already existed, so China did not have to reinvent the wheel.

However, many other countries have not been able to take advantage of these technologies.

Second, it is key that China's central leadership has a clear plan and strong emphasis on environmental protection."It is important that the top leader insists on ecological protection or conservation," Fang said.

The central authorities can use many kinds of performance reviews to evaluate local governments, putting pollution control as part of their performance review. The Communist Party of China (CPC) has a special supervisory team to determine if local governments seriously implemented the central authorities' policies, including environmental policy. This is really serious for local leaders, she said.

Law enforcement through environmental supervision makes it a serious law, not just a law found on bookshelves, Fang added.