Shanghai's environmental performance improved in 2023, with continued progress in air and water quality, according to an announcement released by the Shanghai Municipal Bureau of Ecology and Environment on June 5.

June 5 marks World Environment Day, a United Nations initiative to encourage global awareness and action to protect the environment.

Air quality improvement

Shanghai experienced 320 days of good or excellent air quality in 2023, an increase of two days from 2022. The proportion of days with good air quality rose to 87.7 percent, up 0.6 percent from the previous year.

Of these days, there were 132 days of excellent air quality, 188 days of good air quality, 41 days of lightly polluted air, three days of moderately polluted air, and one day of severe pollution.

Over the past five years, major air pollutants, including PM2.5, PM10, sulfur dioxide, nitrogen dioxide, and carbon monoxide, have generally decreased or remained at low levels.

The average density of PM2.5 − a key indicator of air pollution − increased by 3 micrograms from a historic low in 2022 to 28 micrograms per cubic meter in 2023. Despite this rise, the level remained relatively low.

Ozone pollution

The report highlighted that increasingly prominent ozone pollution has become the main obstacle to the continuous increase in the number of good air quality days.

Since 2017, ozone has replaced PM2.5 as the primary pollutant in Shanghai's air pollution control efforts. Of the 45 polluted days in 2023, ozone was the primary pollutant for 30 days, accounting for 66.7 percent, while PM2.5 was the primary pollutant for 11 days, accounting for 24.4 percent.

Over the past five years, the 90th percentile maximum daily 8-hour average ozone concentration in Shanghai has shown significant fluctuations. In 2022, it rose to 164 micrograms per cubic meter, exceeding the national Grade II air quality standard by 4 micrograms per cubic meter. In 2023, it decreased to 158 micrograms per cubic meter, the second-highest level since 2018.

Water quality improvement

Shanghai also saw continued improvement in the quality of its surface water.

In 2023, 97.8 percent of the main river and lake sections in Shanghai were classified as Grade II or III under the country's five-tier water quality system, up from 95.6 percent in 2022.

The proportion of sections classified as Grade IV decreased from 4.4 percent in 2022 to 2.2 percent. Grade V sections, which disappeared in 2022, remained absent in 2023.

The concentrations of major water pollutants in Shanghai have been decreasing.

In 2023, the average concentration of ammonia nitrogen was 0.38 milligrams per liter, a decrease of 9.5 percent compared to 2022. The average concentration of total phosphorus was 0.131 milligrams per liter, a decrease of 5.1 percent compared to 2022. The average value of the permanganate index was 3.6 milligrams per liter, a decrease of 5.3 percent compared to 2022.

In terms of groundwater, monitoring points with water quality classified as Grade III, Grade IV, and Grade V accounted for 2.3 percent, 58.2 percent, and 39.5 percent of the total, respectively.

Low-carbon commitment

The dedication to green and low-carbon development has penetrated all sectors and deeply influenced the public.

By the end of 2023, companies regulated by the local carbon trading market had completed the annual carbon emission quota settlement for 10 consecutive years, achieving a 100 percent compliance rate.

The cumulative transaction volume of carbon emission quotas in Shanghai's national carbon trading market reached approximately 442 million metric tons, with a total transaction value of about 24.92 billion yuan ($3.44 billion).

Strong regulatory enforcement

The continuous improvement of the ecological environment is underpinned by robust regulatory enforcement.

In 2023, Shanghai addressed 1,281 ecological violations, imposing total penalties of 107 million yuan.

Various measures, such as production restrictions and shutdowns, were effectively utilized in enforcement actions.

Among these cases, five were transferred to public security for administrative detention, and 12 cases were handed over for criminal prosecution. Additionally, 173 cases were subject to penalty exemptions.

Last year, the Yangtze River Delta region unified the administrative penalty criteria for ecological violations and signed an agreement for ecological data sharing.

The three provinces of Zhejiang, Jiangsu, and Anhui, along with Shanghai, simultaneously implemented the National VI B emission standards for both light- and heavy-duty vehicles.

The region also promotes joint protection initiatives for key transboundary water bodies like Dianshan Lake and the Taipu River, the cross-provincial transfer and disposal of solid and hazardous waste, and the construction of waste-free cities.