Ozone alert 2025 on the Balearic Islands: Heat, traffic and the question of effective countermeasures

The air feels heavy: Ozone alert between the promenade and the airport

Anyone who walked through Palma this summer knows the feeling: blue sky, dazzling sun, but the air hangs heavier over the city. Cicadas screech, street cafés are full, and on the Vía de Cintura cars, scooters and delivery vans queue in time with the traffic lights — perfect ingredients for ground-level ozone. Measurements, last seen in 2018, confirm: 2025 was an ozone year.

Central question: Can the islands still get ozone peaks under control?

The simple answer is: not with a single recipe. Ground-level ozone is not emitted directly; it is the child of sun, heat and precursor substances from combustion engines. Several heat waves, hardly any wind and packed streets combined this summer. But the more important, less asked question is: which measures are effective quickly enough to protect people now — and which make sense in the medium to long term?

What often remains underexposed

It's not only cars. Airport activity, ferries in the ports, delivery traffic for hotels and restaurants and construction sites also emit the chemical precursors. In Palma you hear the morning hum of PM-12, the diesel smell along delivery zones and the honking on hot afternoons. Urban heat islands amplify the effect: dark pavement and missing trees store heat and favor ozone formation.

Another point: monitoring networks are patchy. On Menorca, especially in places like Maó and Es Mercadal, values were often above recommended guidelines — but many municipalities have only a few monitoring stations. There are hardly any mobile sensors, so those affected often only notice that the air is bad when their eyes sting or coughing begins.

Who is affected — and why this is not just a health but also a social issue

Most affected are children, older people and people with asthma or cardiovascular diseases. For families living in courtyards without air conditioning, a hot afternoon with high ozone levels means closing windows and enduring the heat indoors. For outdoor workers or delivery drivers it means longer exposure to fine particles and ozone. Air quality is therefore also a question of social justice — those with longer commutes or who live in more densely populated areas bear the burden.

Concrete, short-term effective measures

There are measures that could take effect relatively quickly if implemented consistently:

1. Warning systems and behavioral guidelines: daily warnings by SMS, WhatsApp or local radio stations, clear recommendations for schools and sports clubs and targeted advice for older people.

2. Temporary traffic rules on hot days: time-limited driving bans for heavy delivery vehicles in city centers, reduced speed limits to avoid stop-and-go traffic and thus fewer emissions.

3. Mobile monitoring stations: quickly deployable sensors in affected municipalities like Maó and Es Mercadal would create transparency and allow targeted warnings.

Long-term levers — what Mallorca would really have to change

In the long run, structural changes are necessary: electrification of taxis, buses and delivery fleets; expansion of public transport to the peripheries of the islands; creation of more shaded green corridors in cities; reflective asphalt alternatives and smart urban planning that counteracts heat islands. Subsidies for small businesses switching to electric delivery vehicles could act faster than large projects.

Another often neglected lever is coordination between island governments, municipalities, airport operators and port authorities. Ozone does not stop at municipal borders — and therefore the response must also be coordinated regionally.

Outlook: Don't blame everything on the weather

Yes, the weather makes many things easier or harder — but the concentration of emissions and urban conditions make a decisive contribution. An older neighbor in Palma sums it up pragmatically: 'We always have sun — but the air must not be the price.' Small everyday changes, like fewer short trips, choosing a bike instead of a car for short distances and considerate delivery times, help immediately. Sustainable solutions, however, require planning, money and political will.

The Balearic Islands face a double challenge: short-term protection for people this summer and long-term strategies against recurring ozone events. The question remains open — and pressing: do we only want to react, or start making the islands more resilient before the next hot summer arrives?