What if the population keeps growing?

The UK population grew by almost half a million last year to 64,596,800. What might happen if it continues to increase?
Since the end of the 1990s the UK has been experiencing a population growth spurt.
Between mid-2013 and mid-2014 its population rose by 491,100 people, compared to an increase of just below 150,000 in 1996-97.
For some this growth represents a strain on public services and quality of life, while others believe it underpins economic growth.
Benjamin Zand reports.