China's explosive growth has wreaked havoc on its environment, and for decades, the government paid it little more than lip service. But the ruling Communist Party has changed its tune in recent months, acknowledging the extent of its pollution crisis, and taking aggressive action to curtail it.

Last week, the government passed sweeping amendments to its environmental protection laws — the first changes in 25 years — imposing tougher penalties for polluters and making it easier for whistleblowers and advocates to report polluting companies. When it goes into effect next January, the law will establish "environmental protection as the country's basic policy."

The amendments passed this month mark the latest in a series of recent moves to curb pollution in China, where environmental concerns have become a hot political issue. Late last year, the government announced its first national plan to combat climate change, and it has already committed $280 billion to cleaning its air. In March, Premier Li Keqiang said China will "declare war" on pollution, describing the country's smog problems as "nature's red-light warning against inefficient and blind development."

A "red-light warning"

Rapid industrialization and a burgeoning middle class have strained resources in China, with devastating effects on its air, land, and waterways. Coal-burning plants have fueled regular smog crises in some parts of the country, and widespread pollution has put extra pressure on limited water supplies. Earlier this month, the government announced that one-fifth of its farmland is contaminated by pollutants like cadmium and arsenic. And despite world-leading investments in renewable energy, China continues to rely heavily on fossil fuels to meet its energy needs: it remains the world's largest emitter of carbon dioxide, and accounts for about one-third of the world's greenhouse gas emissions.

Experts are cautiously optimistic about the revised legislation, describing it as an encouraging sign that the country is getting serious about environmental stewardship. Although China has announced several initiatives to tackle pollution in the past, few have been implemented, and the government has long been reluctant to acknowledge the extent of the damage.

Its efforts have been especially hindered by weak central oversight from the federal Ministry of Environmental Protection, as well as vested industrial interests that are intrinsically linked with local governments, weakening incentives to implement change. The stiffer penalties announced last week could signal a transformation: executives of polluting companies can be detained for up to 15 days under the amended legislation, and local government leaders who cover up environmental abuses risk being demoted or fired.

"What's most exciting is that there are parts of it that are trying to give the Ministry teeth," says Jennifer Turner, director of the China Environment Forum at the Wilson Center. "That's been a vital weakness in China's environmental enforcement for a long, long time."

"People in China are unhappy because their health is being very immediately impacted."

The Chinese public has become more aware of the country's environmental crisis, and have begun voicing their concerns through both social media and public demonstrations. In late March, about 1,000 people demonstrated outside government buildings in the southern city of Maoming to protest plans to build a new chemical plant. Similar demonstrations sprouted elsewhere in the country, and hundreds of protests occurred last year, underscoring an ongoing and important shift in thinking on environmental issues.

"Up to 10 years ago people would say that pollution's part of the story — we endure it for economic growth," Turner says. "And I would say in general now, you don't hear people saying that. People in China are unhappy because their health is being very immediately impacted." A study published last year found that poor air quality led to 1.2 million premature deaths in 2010 alone, while carcinogenic contaminants found in Chinese soil have been linked to kidney damage and other diseases.

Although China has made moves toward transparency, environmental issues remain sensitive for government censors. Earlier this year, the country censored a study that said the country's air problems have made some cities "unsuitable for human habitation," and removed social media posts that questioned the government's response to a February smog crisis. As recently as 2012, officials claimed that China's air quality was actually improving, despite clear evidence to the contrary.

"They've taken the gloves off."

But the problems have become too glaring for even the Communist Party propaganda machine to ignore. When record-level smog blanketed Beijing last year, China's state-run media outlets didn't hesitate to criticize the government, questioning its growth model and calling for greater transparency on environmental data.

"They've taken the gloves off," Turner says of the Chinese media. "They're not pulling any punches on any reporting on pollution."

Fear of wider unrest has spurred the government to take action, experts say, though there are economic considerations, as well. Beijing realizes it must transition to a more sustainable growth model — hence the enormous investments in renewable energy — but doesn't want to disrupt an economy that has blossomed on the strength of polluting industries. "They're trying to rip out China's growth engine and replace it with a new one, a green one, while keeping the economy going ahead at 100 miles an hour," says Anna Snyder, China analyst at Rhodium Group, a New York-based consultancy.

The amendments passed last week stand as the clearest sign yet that change is on the horizon, though it's not yet clear whether the government will be able to enforce them. Chinese leaders are no strangers to lofty rhetoric, Snyder notes, though seeing it through has proven more difficult.

"As ever, the language is incredibly exciting," she says. "It's obvious that Chinese leaders know that environmental reform is a categorical imperative. But whether or not there is going to be the institutional capacity to uphold all these really high-minded reforms is unclear... Implementation is everything."