PM2.5 DECLINING IN CHINA SAYS WORLD METEOROLOGICAL ORGANISATION
World in a vicious cycle of climate change, wildfires and air pollution – causing spiraling negative impact on human health, ecosystems and agriculture, says WMO.
Fine particle air pollution declined in China last year as emissions linked to human activity dropped, the UN’s World Meteorological Organisation (WMO) said in its State of the Global Climate 2023 report published this week.
Nanoparticles known as PM2.5 — due to their size smaller than 2.5 micrometers in diameter — pose a severe risk to human health when inhaled over long periods of time as they are tiny enough to get into the bloodstream.
The particles come from human activity like the combustion of fossil fuels, transportation and industry, as well as wildfires and wind-blown desert dust.
The 2023 data shows a drop in PM2.5 compared to the reference period of 2003-2023 over China and Europe. Exceptionally high levels of air pollution in North America in 2023, compared to the two previous decades, were caused by major wildfires, the report said.
The decline in pollution in China is the direct result of lower emissions over the years, said the WMO.
The report noted that ambient air pollution causes more than 4.5 million premature deaths annually and wreaks a high economic and environmental cost.
Particulate matter has a major impact not just on health, but also on agriculture.
It can reduce crop productivity in areas where maximizing yield is of crucial importance for feeding the population. Particulate matter can reduce crop yields by up to 15% in highly polluted areas. It reduces the amount of sunlight reaching leaf surfaces and physically blocks leaf stomata which regulate exchange of water vapour and carbon dioxide with the atmosphere.
The report stressed that air quality and climate change were closely linked. The chemicals responsible for atmospheric pollution, the WMO said, are usually emitted at the same time as greenhouse gasses.
Climate change and air quality cannot be treated separately. They go hand-in-hand and must be tackled together, WMO Deputy Secretary General Ko Barrett said.
According to the report, we are in a “vicious cycle of climate change, wildfires and air pollution is having a spiraling negative impact on human health, ecosystems and agriculture.”
Source: World Meteorlogical Organization, September 5, 2024. https://wmo.int/…/vicious-circle-of-climate-change…