Monitoring the concentration of human-made atmospheric pollutants is critical for advancing science, understanding the consequences of emissions, and developing policies and mitigation measures, the WMO bulletin noted.
By Salam Rajesh
Atmospheric composition affects climate, human and ecosystem health, agricultural productivity, and much more, reads the latest fifth edition of the WMO Air Quality and Climate Bulletin.
The bulletin (05 September, 2025) while providing brief overview of some notable aspects of air quality and climate change during 2024, features articles that highlight the relevance of existing data and the importance of addressing data gaps in atmospheric composition monitoring.
The World Meteorological Organization (WMO) Air Quality and Climate Bulletin seek in reporting on the state of air quality and its interconnections with climate change, and to reflect on trends and geographical distribution of pollution amongst other issues.
The 2025 edition emphasizes on two particular areas, namely, the impacts of anthropogenic influences on aerosols, and the atmospheric composition monitoring and modeling infrastructure availed across the globe.
Quoting few examples, the bulletin emphasized that across the globe Canada and Australia were among the worst affected countries during 2023. Notably, these two countries experienced devastating wildfires last year, incurring huge losses in forests, properties and lives, and impacting millions of wildlife as in Australia.
The bulletin points out that part of central Africa and western North America were also affected tremendously. The highest anomaly, however, was in the Amazon basin, as part of a record wildfire season and record wildfire smoke concentrations in Latin America.
The extensive wildfires in the western Amazon region and in northern South America were facilitated by drought conditions. Neighboring Chile, too, was affected by deadly wildfires, the bulletin noted.
These events not only impacted ecosystems and society to a large extent, but also resulted in widespread negative impacts on air quality, including in densely populated urban areas globally, according to WMO.
Meantime in India, Tarun Gupta and Pradhi Rajeev reporting on the persistence of winter fog in the Indo-Gangetic Plain (IGP) emphasized that mushrooming of urban areas within the IGP had led to enhanced emissions and to the development of urban heat islands, altering local weather dynamics. The primary sources of emissions included vehicles and construction, they stated.
Quoting another source for emission in the IGP region, Gupta and Rajeev stressed that ammonium emitted from large cattle populations and poor sanitation facilities in the peri-urban areas is adding to the issue.
Atmospheric conditions being dynamic and varied across regions, the WMO bulletin provides few examples of the consequential and complex interplay between aerosols, reactive gases and long-lived greenhouse gases.
One of the case studies looks at aerosols from agricultural practices that alter weather at a local level, by extending the duration of fog episodes. Yet another study examines the measures aimed at reducing pollution, with consequences on Earth’s radiative balance, and, therefore, on climate. A third study explores the impact of emissions from wildfires in remote forested areas on air quality in faraway cities.
Monitoring the concentration of human-made atmospheric pollutants is critical for advancing science, understanding the consequences of emissions, and developing policies and mitigation measures, the WMO bulletin noted.
The bulletin further stressed that these measures aim to manage climate change and protect populations from negative health impacts, protect crops from reduced yields, and protect ecosystems from degradation.
The emissions of PM(particulate matter)2.5 originate from human activities such as transport, industry and agriculture, as well as from natural sources like wildfires and wind-blown desert dust, while the formation of secondary aerosol particles from gases like sulfur dioxide, nitrogen oxides, ammonium and volatile organic compounds is an important additional source of PM2.5, the bulletin noted.
Quite interestingly, a recent gazette notification of India’s Ministry of Environment, Forest & Climate Change (11 July, 2025) affirmed that the Central Pollution Control Board, based on a detailed analysis, submitted its recommendation on the National Ambient Air Quality Standards of Sulphur dioxide across most of the regions in the country.
The CPCB submission noted resource conservation in terms of avoiding additional consumption of water, auxiliary power, and limestone; increase in carbon footprint or Carbon dioxide emission into the atmosphere due to operation of control measures being deployed, and mining and transportation of limestone required for these control measures; and the techno-economic feasibility of implementation of such control measures in all coal or lignite based Thermal Power Plants.
The submission further emphasized applying precautionary principle for the control and abatement of air pollution in densely populated areas and other air pollution sensitive areas.
Joeri Rogelj and Lavanya Rajamani writing in science.org (19 June, 2025) noted that the prospect of global warming reaching 1.5°C is deeply concerning and demands sustained attention and decisive action.
Approaching, reaching, and surpassing 1.5°C will have profound implications, disproportionally affecting the poor and vulnerable. In response, global climate governance needs to veer toward better and tighter mechanisms of accountability to achieve near-term emissions reductions and a commensurate focus on adaptation, loss and damage, and support, the authors stressed.
Current deliberations on climate change implication indicate that the 1.5 degrees Celsius warming limit had already been crossed in recent times, even as years 2023 and 2024 were named as the warmest years on record in a century’s time, with year 2025 set to overtake both the record years. The race is now on limiting global temperature rise to 2 degrees Celsius by the year 2050 at best.
The average population in non-descript areas like Manipur in the far-flung eastern corner of India where the subjective talks on climate change is relatively new are finding hard to digest how the climatic and weather anomalies are disrupting life as never before.
Cloudbursts have become the norm in the Himalayan region, and vulnerable regions in Kashmir, Uttarakhand, Himachal Pradesh and Sikkim are testimonies of recent disasters that devastated homes and infrastructures. As global temperature continues to rise, there is no telling where the next disaster would take place. No continent is safe from climate change impacts, so to say.