Why pollen, pollution and hay fever matter to Gibraltar

By Annabelle Mor-Codali, president of the Gibraltar Horticultural Society

For many people, hay fever was once seen as a seasonal inconvenience, a few weeks of sneezing, itchy eyes and blocked noses. Today, scientists are warning that pollen allergies are becoming part of a much bigger environmental story: climate change, air pollution and rising carbon dioxide.

Plants need carbon dioxide to grow. In simple terms, CO₂ acts almost like food for plants. But when there is too much of it in the atmosphere, some plants grow faster, flower earlier and produce more pollen. Warmer temperatures also extend the growing season, meaning pollen can be released earlier in the year and for longer periods.

Recent research linked to the Lancet Countdown Europe report found that climate change has already extended pollen seasons in parts of Europe by one to two weeks compared with the 1990s. This may not sound dramatic, but for people who suffer from hay fever or asthma, it means more days of exposure, more symptoms and a greater impact on everyday life.

The problem does not stop there. Air pollution can make pollen more irritating. Tiny pollution particles from traffic, shipping, industry and fuel combustion can attach to pollen grains or damage them, helping allergens penetrate deeper into the lungs. A 2026 scientific meta-analysis found links between pollen levels and pollutants such as NO₂, particulate matter and NOx, especially for grass, tree and weed pollen.

For Gibraltar, this is particularly relevant. We live in a small, densely built environment, with heavy traffic, limited open green space in some areas, shipping activity nearby and a warm climate. Gibraltar’s own air quality information states that around half of local manageable emissions come from transport, dominated by road transport and local boats, while electricity and energy use also contribute significantly. Studies of the Strait of Gibraltar have also highlighted the influence of maritime emissions on air quality in the wider region.

Many families are now noticing something interesting: young people who spend time studying in the UK sometimes return to Gibraltar and find themselves suffering from hay fever more strongly, even some who had never experienced it before. This is anecdotal, of course, but it fits with what science is telling us: allergies are influenced not only by the type of pollen in the air, but also by pollution, heat, humidity, wind patterns and lengthening pollen seasons.

So what can Gibraltar do?

We cannot solve climate change alone, but we can act locally. Reducing unnecessary car use, improving public transport, encouraging walking, planting more trees and shrubs, creating green corridors, supporting green roofs and walls, reducing waste, improving energy efficiency and choosing cleaner energy all help reduce emissions and improve air quality. Gibraltar’s Climate Change Strategy already recognises the need to reduce emissions across transport, energy, buildings and waste.

Greening Gibraltar is not just about making our streets more beautiful. It is about public health. More trees, planted in the right places and with the right species, can help cool urban areas, trap dust, support biodiversity and create healthier spaces for people. However, we must also be thoughtful: choosing low-allergen, climate-resilient planting is important so that greening improves health rather than worsening pollen problems.

The connection between carbon dioxide, pollen and hay fever is an indirect but powerful reminder that climate change is not something distant. It is already affecting how we breathe, how we live and how comfortable our children and families feel in their own environment.

By acting locally, Gibraltar can contribute to global change, while also creating a cleaner, greener and healthier home for all of us.