The world saw unprecedented improvement in air quality after several countries imposed Covid 19 lockdown but these lockdowns were not enough to halt the climate change caused by global warming, according to the United Nations.
The World Meteorological Organization (WMO) in its Air Quality And Climate Bulletin said that South East Asia saw a 40 per cent reduction in the level of harmful airborne particles caused by traffic and energy production in 2020.
The Bulletin also mentioned that China, Europe and North America also recorded emission reductions and improved air quality during the pandemic’s first year. It also pointed out that countries such as Sweden saw less dramatic improvements as the existing air quality contained comparatively lower microparticle levels (PM2.5) of harmful sulphur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO) and ozone (O3).
WMO’s Atmospheric Environment Research Division Chief Dr Oksana Tarasova said that although the clean air development had been welcome for many people with breathing difficulties, the absence of harmful microparticles left the path clear for naturally occurring ozone, “which is one of most dangerous pollutants”.
“So, despite such an unexpected experiment with atmospheric chemistry, we noticed that in many parts of the world, even if you take down the transport and some other emissions, air quality would not meet the requirements of the World Health Organization,” she said.
STORMS
Despite human caused emissions of air pollutants fell during Covid 19 restrictions and lockdown, weather extremes fuelled by climate and environmental change triggered unprecedented sand storms including the June 2020 “Godzilla” dust cloud – the largest African dust storm on record – and wildfires from Australia to Siberia, which have worsened air quality significantly.
The WMO said that this trend continued in 2021, pointing to devastating wildfires in North America, Europe and Russian tundra.
4.5 MILLION POLLUTION VICTIMS
The WMO also noted that air pollution has a significant impact on human health. It said that the latest Global Burden of Disease assessment showed that global mortality increased from 2.3 million in 1990 – with 91 per cent owing to particulate matter, nine per cent attributed to ozone – to 4.5 million in 2019 – 92 per cent from particulates, eight per cent from ozone.
The Bulletin, considered WMO’s first, is based on studying key air-pollutants from more than 540 observation stations in and around 63 cities from 25 countries.
In the analysis, the WMO said that there was a decrease of about 30 to 40 per cent overall of PM2.5 concentrations during full lockdown in 2020, compared with the same periods in 2015–2019.
WMO noted that PM2.5 levels exhibited complex behaviour even within the same region, with increases in some Spanish cities. It also showed that ozone concentrations varied greatly across regions, ranging from no overall change to small increases – as in Europe – and larger increases (up 25 per cent in East Asia and up 30 per cent in South America).
Sulphur dioxide concentrations were 25 – 60 per cent lower in 2020 than during 2015–2019 for all regions, according to WMO’s Bulletin. Carbon monoxide levels were lower for all regions, with the largest decrease in South America, of up to approximately 40 per cent.
