A potential increase in metal consumption emerges as only concern in a broad-based investigation of the clean-energy transition

The history of environmental protection is full of unforeseen consequences: taller chimneys only led to pollutants spreading wide and far, and safe refrigerants replacing hydrocarbons turned out to damage the ozone hole. How can we ensure that technologies we employ to reduce greenhouse gas emissions do not give rise to the next generation of problems? Protecting the climate demands a fundamental reorganization of some aspects of our economy. How can we make sure that we select and develop solutions that offer us the largest net benefit?

The International Resource Panel has now released the second in a series of reports investigating potential environmental trade-offs and co-benefits of green technologies. This report addresses energy efficiency, while the first report addressed renewable energy and CO2 capture and storage. The report provides strong support for energy efficiency strategies: they are very effective in addressing a wide range of pollutants, as well as land and water use. It offers the most detailed look at the potential side-effects of efficiency to date.

Research teams studied individual technologies, such as LED lighting, building energy management systems, and efficient copper smelting, in order to get an understanding of the resource requirements of manufacturing, use and disposal of efficient devices and their performance relative to conventional technologies. Going beyond individual technologies, implementation of new technologies was modeled in the context of their entire market and value chain. The approach is maybe most neatly illustrated by the work on transportation systems for goods and people, conducted by colleagues in California and Arizona. For example, the study on goods transport considers the shift of transportation mode – from land to rail to road – that is typical for many movements. For personal transport, it considered improvements in competing technologies as well as in the underlying electricity system which becomes more important as e-mobility advances.

Research results on different technologies were integrated in a life-cycle model of the global economy, built specific for the purpose and specified to reflect the changes in the electricity mix and the economy that come with the realization of the 2-degree and 6-degree scenarios of the International Energy Agency. The model captured the interaction of implementing a whole portfolio of clean technologies in the 2-degree scenario. It compared those with the utilization of conventional technologies in the 6-degree scenario.

Through the clean-energy scenario, 17 million tons of particulate matter per year can be avoided, saving many lives. Water use can be reduced by 200 billion cubic meters, land use by 150’000 km2.

Individual technologies contribute substantially. For example, building insulation would reduce life cycle greenhouse gas emissions by 30-50%.

Echoing findings of the earlier report, the new technologies would require more metals. Both PV and LED technologies rely on a wide range of specialty metals, while railways rely on steel. The new report offers little indication whether this increased metal demand poses a problem or not. An important issue that will be on the agenda for the International Resource Panel and other sustainability research. Our previous study, just of the electricity sector, showed that the additional metal demand for just electricity generation was modest, though, with potential concerns only related to the use of copper.


More information on the individual technologies can be found in a special issue of the Journal of Industrial Ecology.