By 2014 more than 75% of Canadian Prairies' cropland had adopted "conservation tillage" and more than 50% had adopted no till. Twenty-five countries pledged to adopt the practice at the December 2015 Paris climate talks. In California multiple Resource Conservation Districts (RCDs) support local partnerships to develop and implement carbon farming, In 2015 the agency that administers California's carbon-credit exchange began granting credits to farmers who compost grazing lands. In 2016 Chevrolet partnered with the US Department of Agriculture (USDA) to purchase 40,000 carbon credits from ranchers on 11,000 no-till acres. The transaction equates to removing 5,000 cars from the road and was the largest to date in the US. In 2017 multiple US states passed legislation in support of carbon farming and soil health.