Summer systems · TOEFL iBT through the season

In recent decades, epidemiologists have documented a striking pattern across Southern Europe: heat has quietly overtaken cold as the leading weather-related cause of excess mortality. A large 2023 Lancet study estimated that more than 61 000 people died from the 2022 European summer heatwaves — a figure that would have seemed almost unthinkable a generation ago.

However, the impact is uneven. Elderly residents in dense inner-city neighbourhoods, where the urban heat island effect intensifies night-time temperatures, are far more vulnerable than younger populations in rural areas. Chronic cardiovascular and respiratory conditions are often the underlying cause; heat is the trigger.

Public-health experts increasingly argue that summer heat should be treated as a permanent infrastructure problem, not an occasional emergency — requiring cool centres, shaded transit and building retrofits, rather than short-term warnings alone.

Cities from Madrid to Tokyo are turning to a surprisingly simple design idea to fight summer heat: raise the albedo — the reflectivity — of their rooftops. Painting roofs white, or coating them with high-reflectance materials, can lower indoor peak temperatures by 3–7 °C and cut cooling energy demand by up to 20 percent.

Beyond individual buildings, aggregated «cool roof» programmes appear to reduce the urban heat island effect at the neighbourhood level. New York's decade-long white-roof programme has coated more than seven million square feet of roofing to date, with measurable temperature drops in participating boroughs.

Critics point out, however, that the effect is largely thermal — it does not remove greenhouse gases from the atmosphere. In this sense, cool-roof policy is adaptation, not mitigation. From a long-term perspective, it must sit alongside emissions reductions rather than replace them.

Coral reefs are among the most biologically productive ecosystems on Earth, but they are unusually sensitive to summer heat. When surrounding water rises just 1–2 °C above the seasonal average and stays there for weeks, corals expel the symbiotic algae that live in their tissue and give them their colour — a phenomenon called coral bleaching. Without the algae, the coral loses its main energy source.

Recent research suggests, however, that the story is more nuanced than «warm summer = dead reef». Some reef sections recover if the heat stress ends within four to six weeks and if pollution and overfishing pressure is low. Others cross a physiological tipping point and never recover, even in cooler years that follow.

Marine biologists now argue that regional protection — reducing local pollution, restoring fish populations — remains the single most useful lever we have while global mitigation catches up. It appears that reef health is set as much on the ground as in the atmosphere.

The word «overtourism» barely existed in mainstream English before 2015, but it has since become the defining word for summer in cities such as Venice, Barcelona, Dubrovnik and Amsterdam. Between June and September, cruise-ship arrivals, short-let apartments and low-cost flights concentrate millions of visitors in historic centres that were never designed for such intensity.

The economic case for tourism is straightforward — it accounts for roughly 12 percent of Spanish GDP and supports thousands of small businesses. Yet residents point out that the same industry has thinned out permanent populations, priced ordinary families out of central neighbourhoods and eroded the very cultural fabric that visitors came to see.

City councils are now experimenting with tourist caps, higher day-visitor fees, and limits on short-term rentals. It appears that summer, arguably the industry's most profitable quarter, is also the one that most urgently needs regulation.

Solar panels are, paradoxically, less efficient in extreme heat than in cool, bright weather. As surface temperature rises above about 25 °C, each additional degree reduces a silicon panel's power output by roughly 0.4 percent. In a Spanish August afternoon, when panel surfaces can reach 65 °C, this represents a serious loss compared to a bright day in April.

Engineers are responding on two fronts. First, new bifacial panels absorb light from both sides, gaining energy from ground-reflected radiation. Second, passive cooling systems — thin water channels, ventilated mounting frames, high-albedo backings — bring surface temperatures down without draining energy.

Seemingly, the future of large-scale solar depends less on how much sun we have and more on how well we manage the heat that accompanies it. From a long-term perspective, that shift is already reshaping how grids across Southern Europe and the Gulf are planned.

«For most of the last thirty years, climate policy focused almost exclusively on mitigation — cutting greenhouse-gas emissions to slow the pace of warming. That work is still essential. But as recent summers in Southern Europe, the American Southwest and South Asia have made clear, a certain amount of warming is now locked in. This is where adaptation comes in — the difficult, unglamorous work of adjusting cities, agriculture and public health systems to the climate we already have. It appears that the next decade of climate action will be judged not only on emissions curves, but on whether hospitals, transport networks and food supplies can operate through summers that regularly exceed 40 °C.»

«Phenology — the study of the timing of biological events — is one of the quietest but most powerful climate signals we have. Long-term records show that in temperate Europe, cherry blossom, songbird arrival and butterfly emergence now occur, on average, two to four weeks earlier per decade compared to the 1980s. Seemingly minor, but the mismatch matters: some insects hatch before their host plants are ready, and migratory birds arrive after their peak food supply has already passed. This so-called trophic mismatch is being observed across an increasing number of ecosystems. It appears that the summer of a European forest in 2040 will look — and, more importantly, function — quite differently from the summer of 1990.»