The Obama administration is reportedly putting together a proposal to block the construction of new coal plants, unless they're equipped with an expensive technology that traps carbon dioxide emissions. And across the world, China also announced a decision this week to block the construction of new coal plants in three heavily polluted industrial regions around Beijing, Shanghai, and Guangzhou.

The developments are welcome, given that the U.S. and China are the world's two largest consumers of coal.

The U.S. rule would limit new plants' emissions to about half of what typical plants emit, sources told the The New York Times. To comply, new plants would have to be able to capture the pollution and inject it deep underground — a process so expensive that it makes their construction virtually unviable.

China's decision is part of a bigger plan to cut down on the levels of particulate matter in the air.

The country has cause for concern. China is set to burn about 4 billion short tons of coal this year, says Forbes, almost as much as the rest of the world combined. And such consumption is raising alarms about public health. In Beijing in January, particulate matter reached levels 40 times the World Health Organization's safety limits, sending people to hospitals and sparking an outcry.

As part of its response, China's plan aims to cut coal to 65 percent of the country's energy use by 2017, down from 67 percent in 2013.

However, if a decrease of two percentage points — at a time when industrial growth is starting to slow down in China anyway — doesn't sound that amazing, that's because it isn't. Martin Adams, an editor for Hong Kong's Economist Intelligence Unit, told the AP that coal's share was already expected to fall below 65 percent by then. He added, "There's less to it probably than meets the eye." In the future, he says, coal will likely make up a smaller portion of the energy pie, but the actual amount of coal China burns will keep rising.

An analyst at Citigroup, however, recently challenged that idea. He predicted that China's demand for coal would decrease due to slowing growth in manufacturing, a stronger market for renewables and nuclear energy, and efficiency improvements in coal power plants themselves. All together, these factors could bring demand for coal to its peak by 2020, says the analyst.

And what about the U.S. plan? Coal companies say it could cripple the industry by preventing any new growth. But "the practical impact of the rule is likely to be limited," says Bloomberg. The U.S.'s natural gas boom has already gone a long way at deterring coal companies from building new plants:

In 2012, the EPA forecast that no utilities would build traditional coal plants over the next eight years.

“The companies themselves are documenting the fact that it is the widespread availability of low-cost natural gas, and to some degree wind power, that is eroding the viability of coal,” Megan Ceronsky, an attorney at the Environmental Defense Fund, said in an interview. [Bloomberg]