UNITED NATIONS: The surface ozone levels can increase by 20 per cent across Pakistan, northern India and Bangladesh by the middle of the century, warns a UN report released on Wednesday.

In its annual report, the World Meteorological Organisation (WMO) — a UN agency that specialises in climate issues — also warned against an expected increase in the frequency, intensity, and duration of heatwaves. The rising heat would worsen air quality — harming human health and ecosystems — and also increase wildfires across the globe, the report added.

The UN agency explained that if greenhouse gas emissions remained high — causing global temperatures to rise by three degrees Celsius from pre-industrial levels — by the second half of the 21st century, surface ozone levels (would) increase across heavily polluted areas, particularly in Asia. “This includes a 20pc increase across Pakistan, northern India and Bangladesh, and 10pc across eastern China,” the report added.

According to the WMO report, most of the ozone increase will be due to a rise in emissions from fossil fuel combustion, but roughly a fifth of this would be due to climate change. This would then increase heatwaves and amplify air pollution episodes.

Pollution, climate change upsurge risk of ‘climate penalty’, UN’s agency warns

“Therefore, heatwaves, which are becoming increasingly common due to climate change, are likely to continue leading to a degradation in air quality,” it pointed out.

It also warned that the interaction between pollution and climate change would impose a “climate penalty” for hundreds of millions of people.

Another WMO report noted that from March to May this year, Pakistan was gripped by a devastating heatwave, which impacted water supplies, health, agricultural output and the economy, and caused a rapid glacier melt.

It said the ongoing disaster demonstrated once again the need for climate change mitigation and adaptation. It also highlighted the importance of WMO’s drive to ensure universal access to early warnings, which drove anticipatory action through UN alerts for all initiatives and its integrated flood management and flash flood guidance tools.

The report noted that as of Aug 27, Pakistan received the equivalent of 2.9 times its 30-year average of rains. The number of rainy days was also much higher than normal at most places. The heatwaves also caused glaciers to melt, which further worsened the floods.

Published in Dawn, September 8th, 2022