1. U.S. Environmental Protection Agency, Global Greenhouse Gas Emissions Data, https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data , accessed August 28, 2019
2. Enerdata, World Energy Consumption Statistics, https://yearbook.enerdata.net/total-energy/world-consumption-statistics.html , accessed August 28, 2019
3. U.S. Energy Information Administration, International Energy Outlook 2018, https://www.eia.gov/outlooks/ieo/executive_summary.php , accessed August 28, 2019
4. U.S. Environmental Protection Agency, Inventory of U.S. Greenhouse Gas Emissions and Sinks, https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks , accessed August 28, 2019
5. U.S. Environmental Protection Agency, Air Pollutant Emissions Trends Data, https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data , accessed August 28, 2019