In its effort to battle pollution, China says it is adopting revision to the country's Environmental Protection Law, the first changes to the legislation in more than two decades.

With 70 articles being voted into law in place of the original 47, it "sets environmental protection as the country's basic policy," a posting on the government's website said.

Contaminated water, soil and air linked to economic growth at breakneck speed have made China the globe's largest carbon emitter, experts say, and environmental issues have become a principal source of social and political unrest.

Many of the adopted measures are aimed at providing more severe punishment for polluters, says Barbara Finamore of the Natural Resources and Defense Council in New York.

"The pollution is now impossible to ignore," she says. "This is very big news."

The stronger laws will create "a strong incentive for polluters to come into compliance" in the face of possible ongoing daily fines, she says.

The new laws will also offer legal protections for whistleblowers.

The new law will go into effect on Jan. 1, 2015, and would deal "a blow ... to our country's harsh environmental realities," said Xin Chunying of the Legislative Affairs Commission of the National People's Congress.

It comes amid increasing concern over widespread environmental pollution, and is for the most part being hailed by environmentalists.

"On the whole, there are many bright spots," said Ma Jun, head of independent environmental group the Institute of Public & Environmental Affairs.

"The biggest breakthrough is ... that (they) have used a professional document to talk about the disclosure of environmental information and public participation," Ma Jun said. "This, in fact, establishes some of the public's basic environmental rights."

Also under the new laws nongovernment environmental groups can file environmental damage lawsuits in certain situations.

However, it remains to be seen whether the law will be vigorously exercised, says law Professor Alex Wang at the University of California, Los Angeles.

"If citizens truly 'supervise' polluters as the law encourages, China will begin to make progress in turning its environmental crisis around," Wang said in an e-mail. "But the proof is of course in the pudding. Given China's history of weak environmental enforcement, the burden is on regulators to show that they now mean business."