Spending on the UK state pension is also expected to rise from 5.1pc of GDP to 8.6pc of GDP by 2072-73, according to the Office for Budget Responsibility (OBR).
The Tories and Labour have both pledged to keep the pensions triple lock, which guarantees payments rise in line with the highest of price increases, earnings or 2.5pc every year, would remain in the next parliament.
Prime Minister Rishi Sunak insisted on Tuesday that maintaining the policy would be affordable.
However the Institute for Fiscal Studies (IFS) has warned that the triple lock could increase spending by anywhere between a further £5bn and £45bn per year by 2050.
Over recent decades, changes in the pensions industry have transferred all the risk of retirement from employers onto workers.
Defined benefit (DB) schemes, which guarantee pensioners a fixed income level when they retire, are being phased out in favour of defined contribution schemes, which pay out based on the total level of savings and investment gains accrued.
The BlackRock chief said baby boomers who benefitted from DB schemes had an “obligation” to help Gen Zs and millennials save more for retirement.
He said: “Young people have lost trust in older generations. The burden is on us to get it back. And maybe investing for their long-term goals, including retirement, isn’t such a bad place to begin.”
BlackRock is the world’s largest asset manager, overseeing around $10 trillion (£8 trillion) in assets under management.
More than half of those assets are allocated to retirement products.