We’re devoting this episode to the season’s most dreaded stocking stuffer, coal. Travel back in time to the Paleozoic era, where coal starts as rotten plants. Add heat, pressure, and time, and quick as a wink from old Saint Nick - you’ve got coal! And like Santa’s naughty or nice list, learn how coal is graded into four types: lignite, sub bituminous, bituminous, and anthracite. Return to the present, where coal provides 38.5% of the world’s electrical power, and glimpse at the future of alternative fuels. BYO hot chocolate. Sources:How is Steel Produced? by the World Coal Association: https://www.worldcoal.org/coal/uses-coal/how-steel-producedAnnual Energy Review by the US Energy Information Administration: https://www.eia.gov/totalenergy/data/annual/ How Much Do You Consume? by the US Department of Energy: https://www.energy.gov/articles/how-much-do-you-consume  Music for It’s Sedimentary, My Dear is provided by Solar Sleighs.Follow us on Twitter and Instagram. You can also contact us through our website sedimentarymydear.com.