This year’s summer has been one of the harshest in recent memory, with relentless heatwaves gripping most parts of the world. As temperatures soared to unprecedented highs, both cities and rural areas struggled to cope with the sweltering conditions. The prolonged periods of extreme heat have not only tested the resilience of communities and infrastructure, but also led to alarming spikes in ground-level ozone concentrations. A secondary pollutant, ozone is formed through the interaction of heat, sunlight, and precursor emissions. It poses a serious threat to human health and the environment, adding to the already dire impacts of the ongoing climate crisis.
Despite regulatory frameworks in place, controlling, mitigating, and tracking ozone pollution remains a formidable challenge due to long-range transport of pollutants. The Copernicus Atmosphere Monitoring Service plays a major role in monitoring and understanding this complex pollutant, offering tools that are indispensable in the fight against ozone pollution.
READ I SDGs: Global South’s struggle for survival and sustainability
The ozone pollution threat
Ozone (O3), a major air quality hazard, sees its highest concentrations during the summer months in the Northern Hemisphere. From June to September, the combination of longer days with increased solar radiation, stable anticyclonic conditions, high atmospheric pressure, and elevated temperatures creates the perfect condition for tropospheric ozone formation. This summer, CAMS recorded several periods favourable for rising ozone levels, with peaks expected to occur from the end of June through early August.
The formation of ozone is a complex process. Unlike primary pollutants, which are directly emitted into the atmosphere, ozone is a secondary pollutant formed through chemical reactions involving nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. These precursor pollutants are emitted from various sources, including transportation, industrial activities, residential cleaning products, and even vegetation. The interaction between these precursors and solar radiation can occur far from the original emission sources, making it difficult to pinpoint and control ozone pollution.
Health and environmental impact
The health impacts of ground-level ozone are severe. High ozone levels can cause lung inflammation, worsen respiratory diseases, and increase the risk of heat stress. For vulnerable populations, such as the elderly, children, and those with preexisting health conditions, the effects can be particularly devastating. The European Directive on Ambient Air Quality sets strict thresholds for ozone levels to protect human health, yet these standards are frequently exceeded during summer months.
Ozone pollution also has significant environmental consequences. It affects crop yields, reduces biodiversity, and damages vegetation. The European legislation aims to limit ozone exposure to protect ecosystems, but achieving these targets is challenging in the face of rising temperatures and frequent heatwaves.
The CAMS provides detailed atmospheric composition data and near-real-time forecasts of surface ozone concentrations. These tools are essential for understanding the sources and dynamics of ozone pollution, enabling policymakers to develop effective mitigation strategies. The CAMS regional ensemble forecast, for instance, offers valuable insights into the daily fluctuations of ozone levels, helping authorities anticipate and respond to pollution episodes.
With the introduction of new, tougher air quality rules in Europe, the importance of monitoring and reporting ozone levels has never been greater. The CAMS Policy Portal allows policymakers to track the contributions of various sources to ozone and particulate matter concentrations, facilitating informed decision-making and compliance with regulatory requirements.
The fight against ozone pollution is far from over. As climate change continues to drive up temperatures, the frequency and intensity of ground-level ozone episodes are expected to increase. This trend underscores the urgent need for international collaboration and consistent monitoring to curb ozone pollution. The data and tools provided by CAMS are vital in this endeavour, offering the detailed information needed to tackle this complex pollutant.
Ground-level ozone pollution is a significant threat that demands immediate and sustained action. By leveraging advanced monitoring systems like CAMS and implementing stringent emission controls, we can protect public health and preserve our environment. The stakes are high, but with concerted effort and international cooperation, we can mitigate the impact of ozone pollution and secure a healthier future for all.