Doing outdoor sports in summer is becoming more difficult, and in many areas of the world even riskier. A new study published in PLOS Climate shows that climate change is narrowing the time windows in which you can train or compete outside without exposing yourself to dangerous conditions. The problem does not only concern the heat of the early afternoon: in some regions the risk also increases in the morning and, at times, even in the evening.
The study tries to bring together, on a global scale, the main climatic factors that can complicate or stop outdoor sport: thermal stress, extreme heat, heat waves and intense rainfall. The researchers used five climate models from the CMIP6 program, comparing the period 1991-2020 with future mid- and end-century scenarios.
It’s not just “it’s hot”: the hours that can be practiced are being reduced
The most interesting aspect of the work is precisely this: it doesn’t just say that the planet is warming. Measure how much the most suitable time slots for running, playing, training or organizing outdoor competitions become smaller.
To do this the authors mainly use the Wet-Bulb Globe Temperatures or WBGT, an index that combines temperature, humidity, solar radiation and ventilation. It is a tool already used in sport because it helps to understand how much the body really manages to dissipate heat during effort. When values rise too high, the risk of heat stroke, dehydration and physiological stress increases rapidly.
According to the study, already in the recent climate several tropical and subtropical areas often exceed, in summer, the thresholds considered critical for sports practice. But the real leap comes in future projections: by the end of the century, in the high-emissions scenario, large parts of South Asia, West Africa, the Arabian Peninsula, Central America and Southeast Asia could accumulate between 60 and 80 days per season with extreme heat risk in the afternoon hours.
Translated into terms less from paper and more from real life: in many areas of the world entire summer weeks could become terrible for doing sports outside, at least without heavy adaptations. And no, it won’t always be enough to move at six in the morning.
The morning will not save everyone
One of the most striking things is precisely this. In the most exposed areas the risk is not confined to the afternoon. In the most severe scenario, parts of southern Asia and western Africa could experience 20-40 mornings per season above critical thresholds. In some humid areas even the evening ceases to really be a refuge.
For years the most obvious solution has been: train earlier, avoid the worst time, do activities when the air is more breathable. It’s still a useful strategy, but the study shows it won’t be enough everywhere. If the heat begins to bite even in the early hours of the day, the margin narrows considerably.
The authors also considered the heat index, i.e. the perceived temperature combined with humidity. By 2100, some tropical regions could exceed the most dangerous values for more than 60 days per season. Here too the message is rather clear: we are not talking about single isolated peaks, but about an increasingly continuous climate pressure.
The Mediterranean enters the critical zone
Italy does not have a dedicated sheet in the study, but the Mediterranean appears among the areas where the risk is clearly growing. At the end of the century, especially in the high emissions scenario, the region enters a high impact band in the composite index developed by the researchers, which combines heat, heat waves and intense rainfall.
We are not in the most extreme conditions expected for tropical regions, but the sign is there and it closely concerns our summer: more heat waves, more difficult days for training and competitions, more pressure on sports facilities and organizers. And this applies both to professionals and to the rest of the world, which is what interests most people: amateur tournaments, pitches, summer camps, school athletics, city races, sports in parks.
Then there is the question of heavy rains. The study also considers days with more than 20 millimeters of precipitation. Because the problem isn’t just the heat that knocks you out: it’s also the pitch that floods, the ground that loses grip, the race that’s canceled and the facility that doesn’t hold up.
It’s not just a problem for big competitions
When we talk about climate risk in sport we immediately think of the Olympics, the World Cup, marathon runners who collapse and health protocols. Everything right. However, the most concrete change risks being seen first elsewhere: in everyday sport.
Professionalism usually has more room to adapt: it can move schedules, change location, strengthen medical assistance, use better facilities. The big problem concerns ordinary realities, those with fewer resources. The neighborhood team, the municipal sports centre, the youth tournament, the amateur race. Where there is no coverage, there is no cooling, there is not much flexibility, the climate becomes a harder barrier.
And there is a not so small paradox: for years we have been told, rightly, that we need to move more, stay less closed, do physical activity, experience open spaces. Except that climate change is making part of that normality more difficult.
What can be done, and what can’t
The study doesn’t say outdoor sports will disappear. He says something more concrete and less theatrical: increasingly frequent adaptations will be needed. Shifted schedules, mandatory breaks, shade, hydration, more resilient facilities, better protocols, revised calendars and, in some cases, rethought sports seasons.
The same authors also specify the limits of the work: it is a global evaluation, not the precise prediction of the individual sports field or the individual city. The models cannot render in detail all the local factors, from the urban heat island to the shade, from the real wind to the specific organization of activities. But the trend is clear and quite robust.
There is also another important point: the worst impacts are concentrated in the high emissions scenario. This means that the difference between contained emissions and out-of-control emissions is not abstract. It also goes from here: how many safe hours will remain, in the summer, to play a game, a run or a training session without turning sport into a test of survival.
Climate change isn’t just melting glaciers or raising sea levels. It is entering everyday life with a brutality that is more banal and therefore easier to underestimate. Even on a sunny pitch at eight in the morning, when you thought you had avoided the heat and instead he was already there.
