Covid-19 & Air Quality: Learning Painful Lessons to Deliver Long-term Benefit

Updated: Apr 15, 2020

The Current Climate

The spread of coronavirus has been the cause of a worldwide pandemic of which many people have lost their lives. People all around the world have been instructed to stay inside other than those with mitigating circumstances in order to gain control of the virus.

We already understand that our actions can impact the air quality around us, and the long-term stability of our climate system. When we make major changes, it is an opportunity to learn new lessons about this critical system and identify key actions for the future. The Covid-19 pandemic is a painful experience for so many reasons, and we have a responsibility to learn as many valuable lessons as we can during this difficult time.


Exploring the Impact of Lockdown with MappAir® & the Zephyr®

At EarthSense, we’ve used our products and services to explore the impact of the recent UK lockdown on air quality, and, on the concentrations of nitrogen dioxide (NO2). Combined use of our modelling (MappAir®) and measurement networks (Zephyr®) allows us to predict what the UK would have looked like over the last month given no lockdown, and compare that to the national network of measurements which have been taken.


The results are quite striking. Throughout the gradual lockdown from 15th to 23rd March, NO2 concentrations continued to rise in the UK during weekdays. However, our modelling suggests that there were substantial reductions from the levels which would otherwise have been experienced (a reduction from 32 to 23 µg/m3 on 19th March 2020 for example – approximately 30% lower).



EarthSense NO2 concentrations graph
Nitrogen Dioxide Concentrations in the UK

After the Prime Minister’s address on 23rd March 2020, these changes became more marked (down from 39 to 25 µg/m3 on 26th March 2020 for example – a 35% reduction), and reductions in the following week were often over 40%.Running our MappAir® modelling with standard estimates of traffic emissions across the UK, coupled with detailed meteorology, we have created scenarios each hour since the lockdown which show what the UK would have looked like in more normal conditions. We’ve illustrated this below for 3rd April 2020, with our best simulation of the actual picture across the UK contrasted with what would normally have been expected using our modelled MappAir® data On average across the UK, there was a 45% decrease in NO2 concentrations on this day.

NO2 concentrations in the UK
Normal NO2 Concentrations vs. COVID19 Concentrations

Such substantial reductions in pollutant concentrations have come at an unsustainable price to our communities in the short term. However, our best estimates suggest that 20,000 people die each day due to poor air quality across the world (World Health Organisation), and in the United Kingdom, that number is about 140 deaths per day (House of Commons report). We also understand from the latest research that pandemics such as SARS and Covid-19 are more likely to cause death in populations with a higher exposure to pollution. We therefore must learn what lessons we can, and retain those environmental improvements wherever possible.


Lessons for the Future?

Following relaxation of the lockdown, many industries and communities will be evaluating their approach to remote working and the amount of travel required to complete key tasks. It is critical that we reduce total travel within our ecosystem, and therefore support remote working where possible. This is particularly important while our transport systems are reliant on fossil fuels consumed at the point of use, which produce emissions in very close proximity to the wider public.


Furthermore, we have now seen the changes which can be implemented very quickly when public health is in peril. We must understand why the substantial number of air quality deaths each year have not instigated such an effective response, despite the damage which is caused year after year.