Globally, coal still generates more electricity than any other source. In 2017, coal generated 38 percent of the world's electricity--64 percent more than natural gas, which ranked second in electricity generation worldwide. Coal's share in 2017 was no smaller than its share two decades earlier. In that time, electricity consumption worldwide increased by 76 percent. While the global share of electricity from natural gas and from renewable energy each has grown since 1998, their generation has substituted for nuclear and petroleum generation in the world market, rather than for coal generation. Various countries have limited their nuclear generation since the tsunami hit Japan's Fukushima Daiichi nuclear units in 2011, forcing nuclear decommissioning, and petroleum has been on the decline for a long time as a generating fuel.