1. United Nations DoEaSA, Population Division (2019) World Population Prospects 2019: Highlights (ST/ESA/SER.A/423)
2. US EIA (2019) International Energy Outlook 2019 with projections to 2050
3. Kannan N, Vakeesan D (2016) Solar energy for future world: a review. Renew Sust Energ Rev 62:1092–1105. https://doi.org/10.1016/j.rser.2016.05.022
4. US EIA (2018) Electricity and the environment – basics. https://www.eia.gov/energyexplained/print.php?page=electricity_environment. Accessed 18 Mar 2019
5. US EPA (2018) Inventory of U.S. Greenhouse gas emissions and sinks 1990–2016