Heatwaves and Air Pollution Are Becoming a Combined Climate and Public Health Risk

Heatwaves are increasingly recognised as one of the most direct and dangerous consequences of climate change. They raise the risk of heat exhaustion, heatstroke, dehydration, reduced labour productivity and pressure on electricity grids. But extreme heat also creates another problem that is often less visible: it can make air pollution worse.

This connection is becoming more important as governments, companies, and cities prepare for hotter summers. Heatwaves and air pollution are not separate environmental issues. They often reinforce each other through atmospheric chemistry, stagnant weather patterns, wildfire risk and increased energy demand. For communities already exposed to traffic emissions, industrial pollution or poor housing conditions, the combined impact can be severe.

The Forbes article highlights this close relationship between high temperatures and polluted air. Its central point is clear: heatwaves can change both the formation and concentration of pollutants, creating a dual risk for human health and climate resilience. This matters for net-zero policy because many of the actions that reduce greenhouse gas emissions also reduce harmful air pollutants.

Why Heat Can Make Air Pollution Worse

During a heatwave, weather conditions are often hot, dry and stagnant. When winds are weak and the atmosphere is stable, pollutants can accumulate close to the ground instead of dispersing. This is particularly problematic in urban areas, where vehicles, buildings, power systems and industry produce emissions near dense populations.

Strong sunlight and high temperatures also accelerate the chemical reactions that create ground-level ozone. This pollutant forms when nitrogen oxides and volatile organic compounds react in sunlight. These precursor pollutants come from sources such as road transport, power generation, industrial processes, fuel combustion, solvents and some natural emissions.

Ground-level ozone is different from the protective ozone layer in the upper atmosphere. At ground level, ozone is harmful to human health and ecosystems. It can irritate the airways, reduce lung function and worsen respiratory diseases such as asthma. It can also damage crops and vegetation, which creates additional risks for food systems and biodiversity.

Heatwaves can therefore create the conditions for higher ozone levels at precisely the time when people are already under physical stress from high temperatures. This makes the combined risk greater than either issue on its own.

The Role of Particulate Matter and Wildfire Smoke

Particulate matter is another major concern. Fine particles, especially PM2.5, are small enough to penetrate deep into the lungs and can enter the bloodstream. Exposure is linked to respiratory and cardiovascular disease, premature deaths and higher health risks for vulnerable populations.

Heatwaves can increase particulate pollution indirectly by drying vegetation, intensifying drought conditions and increasing wildfire risk. When wildfires occur, smoke can travel hundreds or even thousands of kilometres. Communities far from the original fire may experience poor air quality, even if they are not directly threatened by flames.

Wildfire smoke contains a complex mixture of fine particles, gases and chemical compounds. Its health impacts can be serious, especially for older people, children, pregnant women and people with asthma, heart disease or other chronic conditions. Smoke can also disrupt transport, outdoor work, tourism and public services.

As climate change increases the likelihood of extreme heat, drought and fire weather in many regions, wildfire smoke is becoming a larger air quality issue. This is especially important for Europe, North America and parts of Australia, where recent wildfire seasons have shown how quickly local environmental hazards can become regional or international air pollution events.

Europe Is Especially Exposed

Europe has become one of the clearest examples of how climate change can intensify heat-related risks. Copernicus data has shown that Europe is warming faster than the global average, with recent years marked by heatwaves, droughts, record sea surface temperatures and severe wildfire activity.

This matters because many European cities already face air quality challenges linked to traffic, buildings, industry and geography. In some urban areas, narrow streets, dense construction and limited green space can trap heat and pollutants. During heatwaves, the urban heat island effect can make city temperatures significantly higher than surrounding rural areas.

Southern Europe is particularly exposed to high temperatures, drought and wildfire risk, but northern and western European countries are also facing more frequent heat events. The growing spread of extreme heat means that regions historically less prepared for high temperatures may need to improve cooling infrastructure, public health planning and air quality monitoring.

For policymakers, this creates a need to combine climate adaptation, clean air policy and public health strategy. Heat alerts and air quality alerts should not operate in isolation. When both risks occur together, authorities may need to issue combined warnings, open cooling centres, restrict high-emission activities, protect outdoor workers, and provide targeted support for vulnerable residents.

Public Health Impacts

The health risks from heat and air pollution overlap. Extreme heat can cause dehydration, heat exhaustion and heatstroke. It can worsen kidney, cardiovascular and respiratory conditions. Air pollution can aggravate asthma, chronic obstructive pulmonary disease, heart disease and other conditions.

When these risks occur at the same time, the burden on health systems can increase. Hospitals and emergency services may face more admissions related to heat stress, breathing difficulties and heart problems. Pharmacies, care homes, schools and workplaces may also need to adapt their procedures during severe events.

The most vulnerable groups include infants, young children, older people, pregnant women, people with chronic illnesses, low-income households, people experiencing homelessness and outdoor workers. Those living near major roads, industrial sites or areas with limited green space may face higher exposure to both heat and pollution.

This creates an equity issue. Wealthier households are more likely to have access to well-insulated homes, air conditioning, green neighbourhoods and healthcare. Lower-income communities may live in hotter buildings, more polluted areas or jobs with greater outdoor exposure. Climate and clean air policies, therefore, need to consider social vulnerability, not only emissions data.

Why This Matters for Net-Zero Strategies

The link between heatwaves and air pollution strengthens the case for integrated climate action. Many sources of greenhouse gas emissions are also sources of harmful air pollutants. Burning fossil fuels in vehicles, power plants, industrial facilities and buildings can release carbon dioxide alongside nitrogen oxides, sulphur dioxide, particulate matter and other pollutants.

Reducing fossil fuel use can therefore bring immediate air quality benefits while also supporting long-term climate goals. Electrifying transport, expanding renewable energy, improving building efficiency, reducing industrial emissions and supporting cleaner heating systems can all help reduce both climate and health risks.

This is one reason why net-zero strategies should not be assessed only by tonnes of carbon dioxide equivalent reduced. They should also be evaluated for public health benefits, air quality improvements, resilience outcomes and avoided economic losses.

Cleaner air can reduce healthcare costs, improve productivity, lower absenteeism and improve quality of life. These benefits are often felt locally and quickly, while the climate benefits of emissions reductions accumulate globally over time. For governments and businesses, this makes clean air a practical argument for faster decarbonisation.

Implications for Cities and Urban Planning

Cities are at the centre of the heat and air pollution challenge. They concentrate on people, buildings, transport and energy demand. But they also have many tools available to reduce risk.

Urban planning can help by increasing shade, expanding green infrastructure, improving ventilation corridors, reducing car dependency and designing cooler buildings. Trees, parks, green roofs and water-sensitive design can reduce urban temperatures, although they must be planned carefully to suit local climate, water availability and biodiversity needs.

Transport policy is also important. Low-emission zones, clean public transport, walking and cycling infrastructure, and electric vehicle deployment can reduce urban air pollution. Reducing traffic congestion can also lower emissions and improve public health.

Building policy matters too. Better insulation, passive cooling, reflective materials, external shading and efficient ventilation can reduce indoor heat exposure without creating excessive electricity demand. This is particularly important in countries where many homes were built for colder climates and are poorly adapted to increasingly hot summers.

Business and Workforce Risks

Companies also need to treat heat and air pollution as operational risks. Outdoor workers in construction, agriculture, logistics, utilities and maintenance can face high exposure. Warehouses, factories and commercial buildings may also become unsafe or less productive during extreme heat.

Employers may need to adjust working hours, increase breaks, provide shaded rest areas, improve hydration policies, monitor air quality and review personal protective equipment. During wildfire smoke events or severe ozone episodes, some outdoor tasks may need to be delayed or moved indoors.

Supply chains can also be affected. Heatwaves can disrupt transport networks, reduce agricultural yields, strain electricity systems and affect worker productivity. Poor air quality can lead to restrictions on outdoor activity, school closures or health-related absences.

For companies reporting on climate risk, this is relevant to adaptation planning, workforce safety, business continuity and disclosure. Heat and air pollution risks should be included in physical climate risk assessments, especially for assets and operations in cities, fire-prone regions or industrial areas.

The Energy System Connection

Heatwaves can create a feedback loop in energy systems. As temperatures rise, demand for cooling increases. If this peak electricity demand is met by fossil fuel generation, emissions and air pollutants may rise further. In some regions, high temperatures can also reduce the efficiency of power plants, strain grids and affect transmission infrastructure.

This makes clean, flexible and resilient electricity systems essential. Renewable energy, energy storage, demand response, grid upgrades and efficient cooling technologies can help meet peak demand without increasing pollution. Building efficiency is equally important because the cleanest unit of electricity is often the one not needed.

Cooling policy will become a major part of climate adaptation. Air conditioning can save lives during heatwaves, but inefficient cooling can raise energy demand and emissions. The priority should be efficient equipment, passive cooling, smart controls, district cooling where appropriate and building designs that reduce overheating.

A Combined Policy Response

The policy lesson is straightforward: heatwaves and air pollution should be managed together. Climate mitigation reduces the long-term drivers of extreme heat. Air quality policy reduces immediate exposure to harmful pollutants. Adaptation planning reduces vulnerability to the heat and pollution that are already unavoidable.

Governments can support this integrated approach through stronger air quality monitoring, better public warning systems, clean transport policies, building renovation programmes, urban greening and industrial emissions controls. Public health agencies can identify vulnerable populations and coordinate targeted interventions during high-risk periods.

Data will be central. Real-time monitoring of temperature, ozone, particulate matter and wildfire smoke can help authorities issue more precise warnings. Satellite data, urban sensors and health information can support better planning. For businesses, localised climate and air quality data can inform site risk assessments and workforce protection plans.

The Bottom Line

Heatwaves are not only a temperature problem. They can intensify air pollution, increase wildfire smoke exposure and place additional strain on public health systems, workers, cities and energy networks.

For net-zero strategies, the connection is important because it shows the immediate value of reducing fossil fuel use and cutting emissions. Climate action can also be a clean air policy. Clean air policy can also be a health policy. Urban adaptation can also be economic resilience.

As extreme heat becomes more frequent, treating heatwaves and air pollution as separate issues will become less effective. The more practical approach is to design policies, infrastructure and business strategies around the reality that they are connected risks, with connected solutions.

Source: www.forbes.com