Arizona Public Service Co., the largest utility provider in Arizona, will swear off coal power by the end of the decade, it announced Wednesday. APS gets 22 percent of its energy from its coal-fired Four Corners Power Plant and Cholla Power Plant. Cholla is slated for closure in 2025, and while Four Corners wasn't supposed to close until 2038, Wednesday's announcement bumped that down to 2031. In addition, CEO Jeff Guldner said Wednesday that APS would completely shift to carbon-free power by 2050. The U.S. is the second biggest emissions producer in the world, and a quarter of its emissions come from energy production.

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