A Novel Method for Estimating Emissions Reductions Caused by the Restriction of Mobility: The Case of the COVID-19 Pandemic

The COVID-19 pandemic is the single largest event in contemporary history in terms of the global restriction of mobility, with the majority of the world population experiencing various forms of "lockdown". This phenomenon incurred increased amounts of teleworking and time spent at home, fewer trips to shops, closure of retail outlets selling non-essential goods, and the near disappearance of leisure and recreational activities. This paper presents a novel method for an economy-wide estimate of the emissions reductions caused by the restriction of movement. Using a global multiregional macro-economic model complemented by Google Community Mobility Reports (CMRs) and national transport data, we cover 129 individual countries and quantify direct and indirect global emissions reductions of greenhouse gases (GHG; 1173 Mt), PM 2.5 (0.23 Mt), SO 2 (1.57 Mt), and NO x (3.69 Mt). A statistically significant correlation is observed between cross-country emission reductions and the stringency of mobility restriction policies. Due to the aggregated nature of the CMRs, we develop different scenarios linked to consumption, work, and lifestyle aspects. Global reductions are on the order of 1-3% (GHG), 1-2% (PM 2.5 ), 0.5-2.8% (SO 2 ), and 3-4% (NO x ). Our results can help support crucial decision making in the post-COVID world, with quantified information about how direct and indirect consequences of mobility changes benefit the environment.