Three cards from the deck, as you will see them in BrainBerry: the question, the answer, and an explanation of why.
Challenges of an urbanising world
In which year did the world's urban population first exceed its rural population?
Answer
2007, according to the UN. Before that most people lived in rural settlements; since then the urban population has grown faster than the rural population.
Why
In 1950 about 70 per cent of people were rural. The UN expects the world's rural population to peak and then fall, so the gap should keep widening. The crossover is a milestone, not a sudden change.
The UK's evolving physical landscape
Where in the UK are large areas of slate and schist found?
Answer
Slate is found in Snowdonia in north Wales and in the Lake District. Schist makes up much of the Scottish Highlands, including the Grampians.
Why
These rocks resist erosion strongly, so they hold up steep, rugged mountain scenery. Welsh slate was quarried on a huge scale for roofing, so the quarries and spoil tips are themselves a human mark on the upland landscape.
Consuming energy resources
Why are coal, oil and natural gas classed as non-renewable?
Answer
They are finite stocks that formed from buried organic matter over millions of years, so they are being used far faster than they could ever be replaced.
Why
A stock can only be drawn down. Finding new reserves does not add to the total amount of fuel in the crust; it only moves some of it from the undiscovered column into the usable one.