As of the end of 2014, China had 62 billion tons of anthracite and 52 billion tons of lignite quality coal. China ranks third in the world in terms of total coal reserves behind the United States and Russia.[8] Most coal reserves are located in the north and north-west of the country, which poses a large logistical problem for supplying electricity to the more heavily populated coastal areas.[9] At current levels of production, China has 30 years worth of reserves.[10] However, others suggest that China has enough coal to sustain its economic growth for a century or more.[11]