As Beijing shuts down to limit air pollution, policy makers should use the Paris deal as on opportunity to realize synergies between the protection human health and the climate. Fossil fuels are the largest cause of pollution causing ill health. Depending on the technologies society adopts to reduce greenhouse gas emissions, pollution may go up or down. In a new report of the UN's International Resource Panel “Green Energy Choices: the Benefits, Risks and Trade-offs of Low-Carbon Technologies for Electricity Production”, we examine low-carbon sources of electricity and demonstrate that solar and wind power have significant fewer negative side-effects than CO2 capture and storage.
In the United States, for example, electricity production is responsible for more than a third of greenhouse gas emissions, but it emits two thirds of pollutants causing soils and freshwater acidification , and one sixth of eutrophication of water bodies. The World Health Organization estimates three million fatalities world-wide related to outdoor air pollution. While only a fraction of those are caused by well-operated power plants, society has a long way to go to reduce human health impacts from energy systems.
In the Green Energy Choices report, we have analyzed the environmental, human health and natural resource impacts of geothermal, hydro, solar, and wind power, as well as coal and gas power with and without CO2 capture and storage, over the whole life-cycle of each technology.
This thorough assessment confirms the heavy burden that fossil fuels, and in particular coal, place on human health and the environment. Most renewable power projects cause much less pollution, sparing ecosystems and human health. In fact, the degree of difference is stunning: for instance, manufacturing, setting up and operating wind power plants and photovoltaics cause fewer emissions of harmful pollutants than even simply delivering fuel to a coal fired power plant.
The report also shows that:
- From a life cycle perspective, the greenhouse gas emissions of electricity produced from solar and wind energy are less than 6% of those generated by coal or 10% by natural gas, per unit electricity produced.
- Human health impacts from renewable energy electricity production are only 10-30% of those from well-operated, state-of-the-art fossil power plants.
- Damage to the environment from renewable energy technologies is 3 to 10 times lower than from fossil fuel based power systems.
- Capturing CO2 from the chimneys of power plants and storing it in geologic formations increases other forms of pollution by around one third.
Fortunately, solar and wind power are real success stories of technological progress and their costs have decreased tremendously. Given the high social costs of fossil power, solar and wind technologies are competitive in many situations from a total cost perspective. Yet, some further technological breakthroughs will be required for renewable electricity to meet all our power needs. The problem is the variable availability of renewable energy. Engineers have proposed different options to address this variability, including energy storage in batteries, the production of synthetic fuels, or the evening out of production in continental-scale grids. Our research shows that each of these options comes with its own environmental impact. For short-term variations, on the order of hours up to a day, battery storage can be beneficial given the fossil power it displaces, but batteries cannot even out seasonal variations.
Fossil or nuclear power will hence be required for some time as back-up or to provide a baseload. Given the growing electricity demand, energy scenarios indicate that we will still burn a lot fossil fuel before other energy sources can take over. Hence, additional research is required to evaluate the environmental impacts of fossil fuel production and ways to reduce it.
While some extra pollution cleaning equipment could provide Beijing with cleaner air, reducing coal use would be a better long-term bet to address the issue of air quality as well as climate change.