China is facing its worst power shortage in a decade. That's a problem for the whole world

China is in the middle of a huge power crunch as extreme weather, surging demand for energy and strict limits on coal usage deliver a triple blow to the nation's electricity grid. It's a problem that could last for months, straining the country's economic recovery and weighing on global trade.

Nearly a dozen Chinese provinces have said they are facing a power crunch in recent weeks, including some of the country's most important engines for economic growth. Guangdong province — a manufacturing center responsible for $1.7 trillion, or more than 10%, of China's annual economic output and a bigger share of its foreign trade — has been rationing power for over a month. The restrictions have forced companies across the province to shut down for a few days per week. Some local authorities are warning that power rationing could last through the end of the year.