B2 Core Environmental Science
Instructions: skim the question stems, then press play and listen once, taking notes. Answer all 5 questions, check your score and error analysis — and only then open the study pack (transcript, vocabulary, paraphrases, model notes).
Okay, a question to start with. Why is a city always warmer — sometimes several degrees warmer — than the countryside a few miles away? The sun shines on both, right? This is the urban heat island effect, and understanding it is really about understanding surfaces.
Think about what a city is made of. Dark asphalt. Dark roofs. Those dark surfaces absorb sunlight and store it as heat, then release it slowly — including at night, so the city never fully cools down. Compare a field: grass and soil reflect more energy and cool the air as water evaporates. Add the city's shape — tall buildings trapping heat and blocking wind — plus waste heat from cars and factories, and you've built a warm blanket over the city.
So what are the consequences? First, health. Hot nights are dangerous, especially for older people. My grandmother lives on the third floor with no elevator, and she basically doesn't sleep in August — when the night stays hot, the body never recovers. Second, energy: the hotter the city, the more people run air conditioning, and the more waste heat goes right back outside. It's a loop.
Can we fix it? Partly, yes. Cities are trying reflective roofs and lighter pavement, which bounce sunlight back, and buildings designed to let air flow through. But the single best tool — honestly, the best air conditioner a city can plant — is trees. Shade plus evaporation can cool a street by several degrees. One caution about the numbers, though: the heat island is usually reported as one average for the whole city, and an average can hide a lot of unfairness. The neighborhoods with the most trees and the coolest temperatures are usually the richest ones. And remember, the heat island isn't the cause of climate change — climate change raises temperatures everywhere — but the two add up, and that combination makes future heat waves in cities so dangerous.
| absorb | to take in and keep something — dark surfaces absorb sunlight and store it |
| evaporation | when water turns into vapor and rises into the air, cooling surfaces as it does |
| waste heat | heat produced as a useless side product, for example by cars and air conditioners |
| reflective | able to send light or heat back instead of absorbing it — reflective roofs stay cooler |
| mitigate | to make a problem less severe — cities mitigate heat with trees and pale roofs |
| You heard | It means |
|---|---|
| it hangs around all night | the heat stays in the city even after the sun goes down |
| the best air conditioner a city can plant | trees cool a city more effectively than any machine |
| an average can hide a lot of unfairness | a single citywide number can conceal big differences between rich and poor areas |
Compare with your own notes: did you catch the main claim, the arrows (cause/effect), the contrasts and the compressed examples?