NASA satellites show part of China’s plan to meet its ambitious new UN pledge to cut carbon emissions: solar power.

On Tuesday, China said it would halt the rise in its heat-trapping emissions within 15 years and would boost its share of non-fossil fuel energy use to 20 percent by 2030. Its commitment, similar to the one it made last year in a joint U.S. agreement , comes ahead of UN climate talks in Paris in December.

China’s goal reflects how quickly it’s becoming the world’s leader in solar power. It produces two-thirds of all solar panels, and last year, it added more solar capacity than any other country, according to the International Energy Agency or IEA . Germany still has the most cumulative photovoltaic capacity, but second-place China will likely soon close the gap.

The Gobi Desert reveals why. In the northwestern Gansu Province, where sunlight and land are abundant, construction began nearly six years ago on the country’s first large-scale solar power station.

Recent photos from NASA satellites show that solar panels now cover about three times as much Gobi land as they did three years ago. In 2014, the IEA says, China boosted its capacity from solar panels by 37 percent to reach a total capacity of 28.1 gigawatts. And in 2015, during the first quarter alone, China says it’s added another 5 gigawatts of solar capacity.

China’s spending big on renewable energy. Last year, it invested far more— a record $83.3 billion, up 39% from 2013—than any other country, according to a March report by the UN Environment Programme . The U.S., in second place, invested less than half as much.

Not surprisingly, China’s posted the largest gains worldwide in power generation from renewables, including solar, reports the most recent BP Statistical Review of World Energy .

“China is largely motivated by its strong national interests to tackle persistent air pollution problems, limit climate impacts and expand its renewable energy job force,” says Jennifer Morgan, director of the climate program at the World Resources Institute. She says China, now the world’s largest emitter of greenhouse gases, can meet its climate pledge if it continues its renewables’ push.

“China will work hard to achieve the target at an even earlier date" than 2030, Chinese Premier Li Keqiang said in a statement , according to Reuters.

Indeed, solar’s global future is bright. As its panels get cheaper and batteries store the energy they produce for cloudy or dark hours, the world will see a record boom in solar power, forecasts Bloomberg New Energy Finance . By 2040, led partly by China, solar could account for one-third of new electricity generation.

But will that be enough to curb global warming? Without other major steps, the IEA expects the world will likely still miss the international target of keeping the rise in world temperatures—compared to pre-industrial levels—below 2 degrees Celsius.

The story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge .