The world is on track to spend $2.5 trillion annually for the next two decades to meet energy needs, according to the United Nations Environment Program (UNEP). Spending that money on fossil fuels, the agency reports in a new study, will incur environmental costs many times higher than if the investment is directed to renewable energy development.
The agency’s report, “Green Energy Choices: The Benefits, Risks and Trade-Offs of Low-Carbon Technologies for Electricity Production,” found renewable energy to be far from environmentally benign. Hydropower can put strains on aquatic ecosystems, disrupting fish migration, eutrophying water bodies and emitting methane from organic matter decaying in reservoirs. Utility scale solar facilities may also need large volumes of water for cooling and for keeping panels clean.
Nonetheless, in a head-to-head comparison on the critical matter of greenhouse emissions, renewable energy as a category carries a lifetime carbon footprint only 5 to 6% of comparably scaled coal power generation. And even the ‘cleanest’ of fossil fuels—gas—produces more than 10 times as many greenhouse emissions over a plant’s lifetime as renewable energy sources.
Other forms of environmental damage were also three to eight times lower from renewables than for fossil fuels over their production lifetime, the UNEP report said.