Crossword Puzzle Crossword: Carbon EconomicsOnline version Explore carbon sources and related terms. by HAJJAR HARTINI WAN JUSOH 1 Nonrenewable energy sources formed from ancient organisms. 2 Energy sources that replenish naturally over time. 3 Organic material used for energy or chemical production. 4 Charred organic material added to soil to improve fertility and store carbon. 5 Gas produced from the breakdown of organic matter. 6 A levy on greenhouse gas emissions to discourage pollution. 7 A cost or benefit not reflected in market prices. 8 Capture and long-term storage of atmospheric carbon. 1 3 4 6 7 2 5 8