The Covid-19 Silver Lining On Rwanda's Environment

In Capital City Kigali, the number of residents has surged from less than 500,000 in 2000, to more than 1 million in 2021. It is set to increase to nearly 2 million by 2030. At the same time, vehicle numbers in the city have increased from just 55,000 in 1999 to more than 200,000 in 2019.

Air pollution is the fourth highest risk factor for premature mortality worldwide. And there is growing recognition that even at relatively low levels, air pollution can cause significant health impacts, such as heart attacks and strokes.

Started in 2016, car-free days is where major roads are blocked off to provide space for collective exercise sessions to promote healthy living. Initially run once a month in 2018, the car-free days were made fortnightly and extended to secondary cities across Rwanda.

Lockdowns to prevent the spread of the novel coronavirus also had a dramatic effect on traffic, creating an opportunity to explore its contribution to air quality. Using Google mobility data - estimates of travel activity developed by Google using mobile telephone data - travel activity was reduced by more than 80% during the full lockdown and by 41% during the partial lockdown.

The full lockdown, which ran from March to May 2020, required all traffic -excluding emergency vehicles- to stay off the streets. This reduced air pollution by around 33%. The consequent partial lockdown, which allowed cars but not motorcycles, reduced air pollution by around 21%, write Andrew Sudmant and Egide Kalisa for The Conversation.