Recent conversations about climate change, emissions, and health have put a spotlight on the world’s energy sources.
As of 2021, nearly 90% of global CO₂ emissions came from fossil fuels. But energy production doesn’t just lead to carbon emissions, it can also cause accidents and air pollution that has a significant toll on human life.
Fossil Fuels are the Highest Emitters
All energy sources today produce greenhouse gases either directly or indirectly. However, the top three GHG-emitting energy sources are all fossil fuels.
Coal produces 820 tonnes of CO₂ equivalent (CO₂e) per gigawatt-hour. Not far behind is oil, which produces 720 tonnes CO₂e per gigawatt-hour. Meanwhile, natural gas produces 490 tonnes of CO₂e per gigawatt-hour.
These three sources contribute to over 60% of the world’s energy production.
Generating energy at a massive scale can have other side effects, like air pollution or accidents that take human lives.
According to Our World in Data, air pollution and accidents from mining and burning coal fuels account for around 25 deaths per terawatt-hour of electricity—roughly the amount consumed by about 150,000 EU citizens in one year. The same measurement sees oil responsible for 18 annual deaths, and natural gas causing three annual deaths.
Meanwhile, hydropower, which is the most widely used renewable energy source, causes one annual death per 150,000 people. The safest energy sources by far are wind, solar, and nuclear energy at fewer than 0.1 annual deaths per terawatt-hour.
Nuclear energy, because of the sheer volume of electricity generated and low amount of associated deaths, is one of the world’s safest energy sources, despite common perceptions.