If China doesn’t begin to limit its coal consumption by 2030, it will be “almost impossible” for the world avoid a situation where global warming stays below 2°C, a new study released Monday found.

The study, led by the U.K.’s Center for Climate Change Economics and Policy and the Grantham Research Institute on Climate Change and the Environment, recommends China put a cap on greenhouse gas emissions from coal by 2020, and then swiftly reduce its dependency on the fossil fuel. The reductions would not only increase public health and wellness and decrease climate change, but could also “have a major positive effect on the global dynamics of climate cooperation,” the report said.

“The actions China takes in the next decade will be critical for the future of China and the world,” the study said. “Whether China moves onto an innovative, sustainable and low-carbon growth path this decade will more or less determine both China’s longer-term economic prospects in a natural resource-constrained world, … and the world’s prospects of cutting greenhouse gas emissions sufficiently to manage the grave risks of climate change.”

The general question surrounding the prevention of climate change is whether the earth can avoid a 2°C situation — that is, whether we can reduce greenhouse gas emissions swiftly enough to keep global average surface temperatures from rising to 2°C (3.6°F) above pre-industrial levels. World leaders, including China, agreed to avoid that 2°C situation in 2009 by signing the Copenhagen Accord in 2009, a three-page nonbinding pledge to fight climate change.

In 2011, one-fifth of the world’s total fossil fuel carbon dioxide emissions came solely from China’s coal, and coal was responsible for more than 80 percent of the country’s 8 gigatons of fossil fuel emissions that year.

But despite increasing calls for China to reduce its coal-burning — not only because of climate impacts but because of infamous, choking air pollution — it has been unclear whether the country has made enough effort to actually make a dent in its consumption. The country has taken steps to replace thousands of small-scale coal mines with large ones, and its largest cities have pledged to make drastic reductions in emissions.

However, a Chinese government report recently found that only a tiny fraction of Chinese cities fully complied with pollution standards in 2013, while approving the construction of more than 100 million tonnes of new coal production capacity in 2013, according to a Reuters report.

“Coal, in absolute terms, is growing in China,” Fergus Green, one of the authors of the study, told ThinkProgress. “But its share of electricity is declining as other sources of electricity take up additional shares of capacity. So we see absolute growth, but signs of serious moderation.”

Green, who co-authored the study along with London School of Economics scholar Nicholas Stern, said the effort was less of an empirical game to try to predict what would happen in China, and more of a recommendation for how the country could realistically reduce its emissions and how those reductions would benefit the country and the world. The paper, he said, was a response to indications from China’s leadership that it is looking to transform growth models to be more efficient over the coming years.

“One doesn’t just go to China and tell them what they should do, but there are serious discussions that are happening in China about when their coal consumption will peak,” he said. “Really what we’re saying is that there are strong benefits for China and for the world in terms of greenhouse gas mitigation if China were to peak at the early end of 2020.”

Green noted that one of the less obvious benefits of China peaking its coal production would be the catalyzing effect it would have on other countries’ efforts to combat climate change. With China as the world’s largest emitter of greenhouse gases, politicians in other countries — including the United States — have made the argument that nothing they do can actually stop climate change from happening.

“If other countries, particularly the United States, can see that China is serious about declining its consumption, it could be potentially a tipping point that does stimulate more ambitious action from other countries,” Green said. “We could actually get an international agreement.”

However, if China does not become serious about reducing its coal consumption soon, the chances of climate change mitigation become lower and lower.

“If China goes beyond 15 gigatons of carbon emissions by 2030, then [mitigation] would be almost impossible,” Green said. “The longer you delay, the more faster the decline has to be, and the more implausible that becomes.”