Warmer temperatures are not only extending allergy seasons but also causing severe health risks, including thunderstorm-induced asthma. As climate change accelerates, pollen seasons are becoming longer and more intense, leaving millions of people vulnerable to life-threatening allergic reactions. In particular, thunderstorms are exacerbating these dangers by breaking pollen into microscopic fragments, which can invade the airways and trigger severe asthma attacks. The situation is expected to worsen as global temperatures continue to rise, leading to greater health burdens and longer seasons of suffering for allergy sufferers worldwide.
Thunderstorm Asthma: A Deadly Phenomenon
Thunderstorm asthma is an increasingly recognized health crisis, and one of its most severe examples occurred in Melbourne, Australia, in 2016. That day, emergency services were overwhelmed, and hospitals saw an eightfold increase in asthma-related cases. As thunderstorm clouds absorbed vast quantities of pollen and released microscopic particles, an unprecedented number of people – some without prior asthma – began to suffocate. Tragically, ten people lost their lives in this event. Environmental health scientist Paul Beggs recalls the horror of the day: “Doctors, nurses, and pharmacists didn’t understand what was unfolding,” he said, describing the event as catastrophic.
How Climate Change Contributes to the Crisis
Climate change is significantly influencing pollen production, allergy seasons, and the frequency of extreme events like thunderstorm asthma. Higher global temperatures are extending the typical allergy seasons, making symptoms last longer and affecting more people. In 2025, experts predict that 39 US states will experience higher-than-usual pollen levels. These levels are also expected to rise in Europe and Australia, where warmer conditions are extending the duration of pollen seasons. The rise in CO2 levels, a key driver of climate change, further accelerates this trend, particularly impacting ragweed, one of the most potent allergens.
The Pollen Problem: More Than Just Sneezing
Pollen, which is vital for plant reproduction, is one of the most common allergens affecting millions globally. As rising CO2 levels enhance plant growth, ragweed in particular thrives. Studies by Lewis Ziska, a professor at Columbia University, have shown that increased CO2 can lead to more prolific ragweed growth and more allergenic pollen. In fact, ragweed pollen has been found to increase by up to 50% in environments with higher CO2 levels. This trend, which is seen not only in the US but also in Europe and parts of Asia, is expected to worsen, significantly affecting global allergy patterns.
Global Reach: From North America to Australia
Thunderstorm asthma events, though rare, have been reported in other parts of the world, such as the UK and the US, with cities like Birmingham and Atlanta seeing similar occurrences. The increase in these rare but dangerous events is largely attributed to rising temperatures, which are also lengthening the pollen seasons. In the US, longer ragweed seasons have already been observed in 10 out of 11 locations across the country. This shift has led to growing concerns that future allergy seasons will be harsher, with millions more people affected by pollen-related conditions.
Rising CO2 and Its Impact on Allergy Seasons
The rising concentrations of CO2 in the atmosphere are directly linked to longer and more intense allergy seasons. A study from 2022 warned that, by the end of the century, pollen seasons could begin up to 40 days earlier and extend 15 days longer than they do today. With this increase, more severe allergic reactions are expected. For example, during the 2000s, the US saw an increase in the amount of pollen produced by plants, which led to 46% more pollen in the air compared to the 1990s.
Strategies for Addressing the Growing Crisis
To mitigate the impact of rising pollen levels, experts suggest several solutions, starting with reducing greenhouse gas emissions to slow down climate change. In the 1930s, cities in the US took action by forming task forces to reduce ragweed and pollen levels, significantly decreasing local pollen production. More recently, cities in Europe, like Berlin, have initiated programs to remove ragweed and control its spread.
Public health experts also recommend urban planners pay attention to pollen-producing plants when designing green spaces. Fuertes, a public health expert at Imperial College London, explains the importance of carefully selecting plants for urban areas to prevent increased exposure to allergens. For example, urban planners should avoid planting male trees, which are responsible for producing large amounts of pollen.
A Global Health Crisis in the Making
The growing link between climate change and allergy seasons is becoming undeniable. As pollen levels rise and extreme weather events like thunderstorm asthma increase, people worldwide are facing a growing health crisis. Reliable pollen monitoring and better urban planning are key to helping those suffering from allergies. But ultimately, reducing global CO2 emissions remains essential in addressing the root cause of the problem. Without swift action, allergy seasons will continue to grow longer and more severe, leaving millions to suffer.