Want to be informed about air pollution data during COVID-19 restrictions?

Massive air quality changes observed during COVID-19 restrictions

Two major air chemical components, which are also atmospheric pollutants, are shown here as a way to detect the changes in air pollution during the period of COVID-19 restrictions. Weekly values from the start of the year for Nitrogen Dioxide (NO2) and Carbon Monoxide (CO), both of them as total column, are displayed for the first weeks of the year (from 1st January).

As we discussed in our previous post, acknowledging the tragic impact of the COVID-19 outbreak on lives and livelihoods, this unprecedented situation presents us with an interesting opportunity to uncover what happens to the air quality around us and worldwide. The data presented here are taken from the Copernicus Atmosphere Monitoring Service (CAMS). Specifically, data come from the CAMS Near Real Time (NRT) Re-analysis which is available a few days behind real time. Re-analyses are combinations of observations (from ground stations, satellite, etc.) and a very advanced physical model. The CAMS NRT Re-analysis is downloaded at ca. 50 km x 50 km horizontal spatial resolution and every six hours (namely four values daily, at 00:00 UTC, 06:00 UTC, 12:00 UTC and 18:00 UTC).

Given the dependency of these variables of external conditions such as type of weather, economic productivity, traffic, etc. a week average is about the shortest time recommended when comparing these type of data across years, though monthly averages would perhaps be more appropriate. As we know, the restrictions due to the coronovirus have have been occurring at different times in various parts of the globe so weekly averages help us better relate these changes with the times the restrictions have been enforced. For a proper comparison, we would also need to assess external factors, so the data below need to be interpreted with a grain of salt. Also, due to the nature of these data there can be discrepancies between the CAMS NRT Re-analysis and the maps which often appear on the web and derived from Sentinel-5P/TROPOMI. Importantly, some, though not all, of these estimates are flawed as discussed in this blog from CAMS.

The movies show the weeks of the year (available to date, i.e. currently week 26) grouped into four, with the following pattern: full field for 2019 (top left), full field for 2019 (top left), difference between 2020 and 2019 (positive means higher values in 2020 compared to 2019, and vice-versa, bottom left), and difference between 2020 and 2019 as a percentage (bottom right). Five views are shown for each variable: Global, Europe, (a large part of) Asia, North America and Middle East. The number in square bracket on the titles is the weighted average for the region. These images will be regularly updated as more recent data become available. Monthly averages are avaialble on request.

For further information, please contact Prof. Alberto Troccoli (alberto.troccoli -at- wemcouncil.org


Data courtesy of Copernicus Atmosphere Monitoring Service (CAMS)

Nitrogen Dioxide (NO2, in 10 -7 kg m-2)

Area averages (same areas in maps below plus Australia) of percentage change of 2020 vs 2019 for NO2 as a function of month of the year
Area averages (same areas in maps below plus Australia) of percentage change of 2020 vs 2019 for NO2 as a function of week of the year

Carbon Monoxide (CO, in 10 -4 kg m-2)

Area averages (same areas in maps below plus Australia) of percentage change of 2020 vs 2019 for CO as a function of month of the year
Area averages (same areas in maps below plus Australia) of percentage change of 2020 vs 2019 for CO as a function of week of the year

What the unexpected COVID-19 virus outbreak teaches us about our environment

Written by Prof. Alberto Troccoli. Edited by Debbie Woodliffe.

The dramatic spread of the COVID-19 Coronavirus has led to several countries restricting the movement of people, including air travel. Previously, we’ve only seen government responses like this when concerned with more terrorist-related incidents – such as the tragic events of September 11 nearly twenty years ago when air traffic ground to a halt for several days. The fact that a virus is causing a larger, more extreme reaction is unheard of.

But this COVID-19 outbreak does present us with an interesting opportunity to uncover what happens to the air quality, and pollution in general, when human induced emissions are forcibly halted.

Fig. 1 – Cases of Coronavirus worldwide. Source: WHO, via BBC.

Removing the human element

These new striking images from NASA and the European Space Agency (ESA) show significant decreases in nitrogen dioxide (NO2) over China since the restrictions began. It’s pretty clear that this rapid drop in NO2 is mainly due to the remarkable reduction in human activity as a consequence of the coronavirus outbreak. Even more impressive changes are seen when you focus specifically on the epicentre of the COVID-19 outbreak in the Wuhan region.

Fig. 2 – Change in No2 concentration. Source: NASA and ESA.

Almost by coincidence, Italy has also been hit, particularly in Lombardy in the north which is one of the most polluted areas in Europe in terms of air quality. Now on total lockdown, this country has the largest number of COVID-19 cases in the whole of Europe.

But, similarly to China, the highly industrialized region of Lombardy in northern Italy has seen a drastic improvement in air quality since the lockdown began. While there may be meteorological factors at play here, it’s almost inevitable that this reduction is a direct consequence of the reduced traffic and economic activity.

What can we learn from the COVID-19 outbreak and the pollution reduction?

First and foremost, it seems evident that a drastic reduction in economic activity and traffic can lead to a sudden (within days as opposed to years) improvement in air quality. We’re not at all suggesting that this sort of economic pause is an exercise worth carrying out just for the sake of seeing a drop in NO2 or PM10 measurements. Particularly given the drastic drop in the stock market which has wiped out over 15% of value in just a few weeks. But it is worth considering how we can conduct business in a way that is more balanced with the environment, and ultimately, with our health.

Fig. 3 – Particulate (Pm10) concentration on 22 February 2020 (left, before outbreak in Italy) and 2 March 2020 (right). Red is for values between 50 and 100 µg/m³ and cyan for values from 0 to 20 µg/m³ (yellow are in between the red and cyan). Source: Arpa Lombardia.

Think about it. If we all adopted a greener way of doing business, almost paradoxically, the better air quality might allow our bodies to be stronger and potentially be more efficient at battling unwarranted respiratory viruses like COVID-19.

Embracing an environmentally friendly future

But how can we achieve such reductions in pollution without damaging the economy? The fact is that the solutions are already available to us, if only we were more willing to embrace change.

For instance, imagine what an (almost) entirely electric fleet would do for the quality of the air? And what if there were enough wind and solar parks, as well as hydro power, to produce enough electricity to displace fossil fuel-based power plants? But it’s not only large changes. What if we decided to shop more locally instead of importing? It could reduce the movement of goods and benefit your local economy. Or how about conducting a meeting remotely through a conference call system, thus avoiding travel emissions? Even taking the bus or cycling to work, or simply taking the less-beaten, more traffic-light road with the assistance of your navigator, could have a positive impact.

If nothing else, we should all take this opportunity to see how each one of us can contribute to improving the environment, and our quality of life. Old habits die hard, but if we all band together and learn from the COVID-19 lockdowns and the resulting environmental impacts, we may yet be able to mitigate the effects of pollution and even climate change.