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Why can a city be warmer than nearby countryside?

The trip from a leafy edge of town to a dense street can also be a trip between different temperatures. Buildings, pavement, vegetation, and waste heat all affect the balance, and the contrast changes with weather and time of day.

3–5 min

Questions you could explore

  • What happens to sunlight absorbed by built surfaces?
  • Why might surface temperature and air temperature tell different stories?

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Environment and climate

What can tree rings reveal about past climate?

A tree keeps a record of growth in its wood, but reading that record as climate history takes more than counting rings. Moisture, temperature, and other growing conditions can leave overlapping clues.

4–5 min

What can tree rings reveal about past climate?

Environment and climate4–5 minA tree keeps a record of growth in its wood, but reading that record as climate history takes more than counting rings. Moisture, temperature, and other growing conditions can leave overlapping clues.

Environment and climate

A trip through a wastewater treatment plant

Water disappearing down a drain begins another journey before it reaches a river or the sea. Uisce Éireann's description of treatment in Ireland separates several different jobs, from screening out objects to biological treatment; the resulting effluent is not drinking water.

4–5 min

A trip through a wastewater treatment plant

Environment and climate4–5 minWater disappearing down a drain begins another journey before it reaches a river or the sea. Uisce Éireann's description of treatment in Ireland separates several different jobs, from screening out objects to biological treatment; the resulting effluent is not drinking water.

Environment and climate

Where does the water go in a rain garden?

Rain runs quickly off a roof or pavement, but a planted hollow can give it somewhere to pause. A rain garden's ability to hold water and let it enter the soil depends on its surroundings and ground conditions.

3–5 min

Where does the water go in a rain garden?

Environment and climate3–5 minRain runs quickly off a roof or pavement, but a planted hollow can give it somewhere to pause. A rain garden's ability to hold water and let it enter the soil depends on its surroundings and ground conditions.

Why can a city be warmer than nearby countryside? | Speech Topic | speaking.app