Soaring numbers of elderly people will put massive pressure on Ireland's already creaking pension systems.
Private and public pensions are already in deep trouble due to people living much longer, and with life expectancy set to grow to 82.9 for men and 86.6 for women by 2031, the pressure will increase.
The age you qualify for a pension at is due to increase to 67 by 2021 and 68 by 2028 to cope, but the OECD is already pushing for us to increase that even further.
Health services already struggle to deal with the medical needs of Ireland's relatively young population, so treating all the illnesses associated with aging will be a huge strain. The number of people with Alzheimer's, for example, is projected to triple within coming decades due to a rapidly aging population.
A 400,000 surge in population in the greater Dublin area would put massive pressure on already congested roads. The M50 could become like an inner ring road as the population oozes further out of the capital while, like London, congestion charges may have to be introduced.
Dublin is already feeling the squeeze of housing shortages and this can only intensify if the population grows as expected.
Planning experts have warned of a shortfall in construction for existing needs, and a 20,000-a-year increase in population will require a big surge in new developments.