The pandemic-related drop in greenhouse gas emissions in 2020 was likely the largest on record in a single year, but how our recovery might affect future emissions is less clear. New modeling examines alternative scenarios and how they could impact climate mitigation targets.

A group of IIASA researchers in the Energy, Climate, and Environment Program performed a bottom-up assessment of changes in energy-related demand and estimated how new patterns of travel, work, consumption, and production might reduce or increase climate mitigation challenges. 

“Many people have been wondering what the large changes in societies that came with the COVID-19 pandemic and its lockdowns mean for climate change,” says Jarmo Kikstra, lead author of the study. “If societies are just moving back to old practices, the answer is that there is virtually no effect. However, if some of the changes in energy-use practices persist, climate mitigation challenges will be affected.”

The research, published in Nature Energy, shows that a low energy demand recovery could reduce a hypothetical tax on all carbon emissions by 19% for a scenario that is on track for reaching the Paris Agreement’s goal of limiting global warming to 1.5°C. This scenario would also lower energy supply investments until 2030 by US$1.8 trillion and soften the pressure to quickly implement renewable energy technologies.

“Our key finding is that missing the opportunity to retain low-energy practices in lifestyle and business would lead to a more difficult energy transition. Our economic recovery and climate mitigation policies should embed strategies to retain the low energy demand practices observed during the pandemic, such as low-carbon mobility in cities and increased tele-conferencing,” says coauthor Adriano Vinca. 

According to the authors, this is especially true when it comes to transportation. In particular, the different recovery narratives of transportation energy demand strongly influence CO2 emission trends.

The researchers examined four different scenarios, each with a consistent set of assumptions about changes in energy demand in buildings, transport, and industry sectors as the world recovers from the COVID-19 pandemic. 

In the “restore” scenario, the use of private vehicles, as well as the intensity of air transport are restored to pre-pandemic levels. The same holds for industrial activities and supply chains, as well as our working practices and domestic life. 

In the “self-reliance” scenario, concerns about health risks linger longer and individuals shift towards private transport while abandoning forms of crowded transport. Office and living space increase to carry on social distancing. In addition, demand for steel is especially strong due to reinvigorated car manufacturing and building construction.

In the “smart use” scenario, people adapt better to working from home and there is a moderate shift to teleworking. This leads to home space being used more intensively, and a slight reduction in motorized transportation growth, compared to pre-pandemic levels. However, a surge in online retailing increases overall road freight transportation.

In the last scenario, which the researchers call “green push”, the highest energy reductions are achieved by changes in space reallocation and reduced private transport. For instance, walking or cycling replaces some of the trips that were previously done by car, and empty offices are repurposed. 

The researchers conclude that compared to a “green push” scenario, the “restore” scenario would increase the energy investments required to meet a 1.5°C climate target by about 9% or $1.8 trillion. This difference is in part due to the need to boost the pace of transport electrification and the upscaling of solar and wind in the “restore” scenario.

“The bottom line is that the “green push” scenario, which supports working from home and teleconferencing to reduce flying and commuting can have strongly beneficial outcomes for climate mitigation challenges,” says IIASA Energy, Climate, and Environment Program Director and coauthor, Keywan Riahi.

The authors further add that it is important to design holistic policies, including the repurposing of office space and the increased use of walking or cycling within cities or public transport when commuting.

As coauthor Charlie Wilson, also of the University of East Anglia, concludes, “limiting global warming to 1.5°C will be exceptionally hard. A tiny silver lining to the COVID-19 cloud is that the 1.5°C target becomes that bit more achievable if we can selectively sustain some of the lower-carbon practices forced upon us by lockdowns.” 

 Scenarios for indicators of the climate mitigation © IIASA

Illustration of the differences across the restore, green push, and self-reliance scenarios for indicators of the climate mitigation challenge in the coming two decades.


Kikstra, J.S., Vinca, A., Lovat, F., Boza-Kiss, B., van Ruijven, B., Wilson, C., Rogelj, J., Zakeri, B., Fricko, O., Riahi, K. (2021). Climate mitigation scenarios with persistent COVID-19 related energy demand changes. Nature Energy. DOI: 10.1038/s41560-021-00904-8


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