Climate scientists have sometimes warned that it could prove impossible to avoid high levels of global warming unless the world stops building new coal-fired plants. But that's not a simple proposition. Across the globe, there are at least 1,199 coal plants now on the drawing board, according to a new report from the World Resources Institute.

Many of these proposed new plants are in China and India, which account for 76 percent of proposed capacity. Turkey and Russia also have big plans. And a growing number of coal plants are being proposed for developing countries such as Cambodia, Guatemala and Uzbekistan, nations that are looking to cut-rate sources of energy to fuel economic growth.

It's still unclear how many of these proposed plants will actually get built. In the United States, for instance, plans for 36 new coal plants are now looking unlikely, thanks to new pollution rules and the availability of cheap natural gas. But in Europe and Japan, once-moribund coal plant proposals are being revived after nuclear reactors were shut down in the wake of the Fukushima disaster.

"We wanted to identify all proposed plants rather than try to assess the likelihood that they'll get built," says Ailun Yang, a co-author of the report. That's because proposed coal plants that appear dead can often come back to life again later. Whether or not these plants get built will largely depend on the policy choices that governments make, as well as market forces such as the availability of natural gas.

And those policy choices could have major implications for future global warming. Coal burning already accounts for about 44 percent of the world's energy-related carbon emissions. If even just a quarter of these 1,199 proposed plants were built, that would be the same thing as doubling the coal capacity of the United States. A massive coal expansion would make it increasingly difficult to slow the pace of climate change.

So a lot depends on how governments will think about coal in the years ahead. And that will vary from country to country. Here's an interactive map from WRI showing the location of the various coal plant proposals:

Take China, which now has at least 363 large plants in the pipeline. The country has likely passed its peak in terms of coal expansion, says Yang; it's no longer building two new plants a week the way it was back in the early 2000s. And some analysts have suggested that China's gargantuan coal appetite could wane in the years ahead, as economic growth slows and pollution concerns become more pressing. So it's quite possible that a big portion of those 363 proposed plants won't ever get built. A lot rests on whether the Chinese government decides to tighten its current voluntary cap on coal consumption or pursue new climate policies.

In India, meanwhile, the coal question is more agonizing. There are still more than 300 million Indians without electricity, and poverty remains widespread. The country isn't quite as far along the development path as China. Only in the past few years have proposals for coal plants really exploded, Yang says, and there's a lot more room for growth. Coal offers a potentially low-cost source of electricity, but also brings some major downsides—from water use and air pollution to speeding along climate change. That makes it harder to predict how many of India's 455 proposed coal plants will eventually get built.

"Both of these countries have made noises that they'd like to take a different development path," says Yang—one that doesn't rely so heavily on fossil fuels. "But they'd have to put in place policies that are strong enough to discourage coal use." And whether or not that actually happens is one of the biggest uncertainties in trying to make climate predictions.

Further reading:

--We’re on pace for 4°C of global warming. Here’s why that worries the World Bank.

--The coal industry is in decline in the United States, but more and more coal is starting to get exported abroad to Asia. So the global rate of plant expansion is certainly a topic of interest to U.S. coal producers.

--The U.S. cut its carbon emissions in 2011, but China erased the gains.