Climate crisis | Extreme weather in the Mediterranean: Hot, hotter, Barcelona

At five in the afternoon, the sun is still high above the Antoni Santiburcio children's playground in Barcelona's working-class district of Sant Andreu. The fact that a few children are still happily climbing on the climbing frame is thanks to the triangular tarps stretched across the small space in a mosaic pattern. The perforations cast a partial shadow on the ground, and it's noticeably cooler below them than on the street next door. "It's about time something happened here. The heat has literally burned the children's brains out," says Flavia Menéndez, hoisting her two-year-old daughter onto the swing. "Especially during the holidays, when daycare centers and schools are closed, the little ones need to get outside."

The playground in the north of the Mediterranean metropolis was the first of a total of 66 playgrounds, 15 schoolyards, and three public squares that have received artificial shade in recent weeks: some are simple tarpaulins, others are permanently installed wooden panels with integrated photovoltaic systems. "Pla Sombra," or "Shade Plan," is the name of the €13 million program. It is one of many pieces of the mosaic of the city's climate adaptation plan.

"The mobile structures allow us to intervene quickly where it's most needed," says Irma Ventanyol, director of the city's climate change office. "And that's where solar radiation is highest and where there are particularly high numbers of vulnerable people, such as children or the elderly." Of course, the best solution is to plant trees as natural shade providers. Because they not only lower the temperature through shading and evaporation, but also improve air quality and the well-being of residents. But in a city as densely built as Barcelona, this is unfortunately not possible everywhere – and often takes too long. "It takes years for the trees to grow large enough to provide shade – and we can't wait that long." So last year, the city tested various modules in strategic locations and is now putting them into practical testing. As an immediate measure against the heat waves of the Spanish summer, which will likely be preceded by the adjective "historic" again this year.

June 2025 was the hottest June in Barcelona since records began; for the first time, temperatures did not fall below 25 degrees Celsius, even at night, for 16 consecutive days. Last year, July saw the highest temperature ever recorded at 40 degrees Celsius. Since the 1980s, the average temperature in Barcelona has risen by 1.6 degrees Celsius. If radical measures to combat climate change are not taken, according to a study published earlier this year in the journal Nature, more than 246,000 people in Barcelona could die prematurely by the end of the century due to the high temperatures. This is more than in any other European city. In addition to dense development, a relatively high proportion of people over 65 (21 percent) is considered a risk factor. Adaptation to rising temperatures is urgently needed: the sooner the better.

A refuge every five minutes walk

Given such forecasts, Ventanyol appears surprisingly calm. "Barcelona is at the forefront of climate adaptation," says the biologist, and lists the following: While other cities are only now developing corresponding strategies, Barcelona has had graduated protocols for heat waves since 2007 – with information campaigns, behavioral tips, and expanded medical care. If daytime temperatures rise above 34 degrees Celsius and don't fall below 26 degrees Celsius at night, the city's hospitals set up heat emergency teams, and home visits are expanded. Special shelters are provided when temperatures reach 38 degrees Celsius during the day and 28 degrees Celsius at night. The 1,700 public drinking fountains have been locatable via an app since 2013 and operate year-round, even during drought alerts. Since 2020, the city has designated so-called climate refuges: air-conditioned sports facilities, libraries, museum foyers, and other public facilities where everyone can find free cooling and drinking water. There are 400 such shelters in Barcelona, each marked with a sign. The network is being continuously expanded. By 2035, every resident is expected to find refuge from the heat within a five-minute walk; currently, the distance is ten minutes. The idea is now being copied by other Spanish cities.

And then, of course: provide shade and create cooling wherever possible, as required. When a new, nine-hectare urban park was inaugurated at the former Glòries traffic junction in early summer, the city proudly pointed to the 1,000 newly planted trees, the futuristic pergolas, and the increase in unsealed surfaces. When creating new squares, gravel sand or paving stones are increasingly replacing asphalt; new bike paths are flanked by green spaces wherever possible. "We consider the heat factor in every urban development measure," says Ventanyol.

By the end of the century, more than 246,000 people in Barcelona could die prematurely due to high temperatures.

The idea of tackling the heat with official urban planning measures is nothing new: In Málaga, the city has been shading the pedestrian zone Calle Larios with tarpaulins stretched across the street for many years, which, according to City Hall, reduces the perceived temperature by five degrees. Seville, too, walks under panels in the city center during the summer. But while Andalusian cities primarily shade the streets of tourist and commercial interest, Barcelona implements its heat plan based on social criteria.

When selecting climate refuges, as well as when greening or shading public spaces, action is taken first in neighborhoods where people with a lower socioeconomic standard live. Development in these neighborhoods tends to be denser; so-called heat islands, where heat accumulates, develop more quickly. Few can afford air conditioning and the associated operating costs, and the buildings are inadequately insulated. "Poorer people suffer more from extreme weather on average than wealthier people," says Ventanyol. "We as a city must intervene."

But a lack of insulation isn't just a problem in socially disadvantaged areas. According to a study by the Universidad Politécnica de Cataluña, by 2050, ninety percent of Spain's housing stock will not be adequately insulated against rising temperatures. Space for new buildings designed according to climate criteria is extremely limited in cities like Barcelona, and adaptation to extreme temperatures can only be achieved through investments in rehabilitation. Nine billion euros are to be spent across Spain in the coming years on climate-neutral rehabilitation measures in apartments, plus another 15 billion euros for improved insulation in buildings. "Most people think that climate adaptation is limited to 'more green,'" says Ventanyol. "But insulating buildings is at least as important, partly because it can reduce greenhouse gas emissions."

Green urban planning projects stopped

Despite the presentable results in terms of adaptation, there is still room for improvement when it comes to mitigation, i.e., reducing climate-damaging emissions. At least, that's what the opposition says. They criticize the fact that the governing mayor, Jaume Collboni of the Catalan Socialists, the counterpart of the German SPD, supports the planned airport expansion. The chairwoman of the left-wing alternative Barcelona en Comú, describes the plan as "irresponsible nonsense." The much-praised program of so-called "superblocks" has also been halted. The idea of transforming the city into a network of traffic-calmed neighborhoods using "green axes" and limiting motorized traffic to a few streets had earned Barcelona a worldwide reputation as an avant-garde in green urban planning.

Anyone strolling along the three-kilometer-long Consell de Cent street in the upper-class Eixample district, one of four "green axes" created so far, gets a glimpse of what such a city might have looked like: Herbs and grasses bloom lushly at the former intersections. Where cars once parked, there are tables and benches where residents and employees from nearby shops meet for lunch. However, following successful legal action by retailers, no new streets will be traffic-calmed for the time being. Instead, the plan is to plant green courtyards.

Natalie Müller from the IS Global Research Center for Global Health regrets this. The project's climate benefits were undisputed: 700 heat-related deaths could have been avoided annually by expanding the concept to the entire city, according to a study she co-authored . "According to our model, emissions would have decreased by almost 25 percent and noise pollution by five percent – and the average temperature across the entire city would have dropped by one degree," says Müller. Even if the city administration continues to plant trees in squares and along roadsides, if this doesn't reduce traffic, the mitigation effect will be lost.

At least the city administration is sticking to its "More Green" strategy, even under extreme weather conditions: When a drought emergency was declared last year and private households, industries, and public facilities were forced to conserve water, tree irrigation was exempt. As important infrastructure, tree preservation was declared a priority.