China may launch an environmental protection tax in four provinces, China Business News cited an unidentified environmental planning official as saying Thursday.

The Ministry of Finance, the State Administration of Taxation and the State Environmental Protection Administration will submit a proposal to the State Council soon for collecting an environmental tax in Hubei, Hunan, Jiangxi and Gansu provinces, the newspaper reported.

The environmental protection tax, likely to be levied on emissions of carbon dioxide and discharge of polluted or waste water, is viewed as part of the central government's drive to make its economic growth greener.

China has vowed to decrease the amount of carbon dioxide produced per unit of GDP by 40-45 percent by 2020.

The tax was proposed by CPPCC members in 2007 as a move to raise awareness of environmental degradation but was not adopted. In 2009, the official Xinhua News Agency published a story saying that conditions for environmental tax legislation were "basically ripe." But the global financial crisis froze the plan.

"Actual environmental problems are always more complicated than theoretical assumptions," China Business News quoted Wang Hui, a lecturer with the law school at Shanghai Maritime University. "The extent of the damage caused by some pollutants actually depends on the amount of emissions and the location of the pollution sources."

China is the world's largest emitter of greenhouse gases and the biggest consumer of coal. The country has a huge need for fossil fuels in order to meet its surging economic demands.

A survey conducted in 320 cities showed that the average air quality in two out of five Chinese cities ranged from "polluted" to "hazardous".

Critics said that China has already adopted taxes such as the fuel tax to protect the environment and the introduction of the new tax might have negative effects on the country's economy, product prices and the ordinary people's daily life. The tax also would become a burden on small- and medium-sized enterprises that are still struggling with the global economic downturn.

China's GDP grew by 11.9 percent in the first quarter this year, and by 11.1 percent for the first half of the year, according to data cited from the National Bureau of Statistics.

The China Federation of Logistics & Purchasing released the purchasing managers' index last Sunday. The figure fell to 51.2 from 52.1 in June, indicating economic slowdown.