Stupid idea.
Much of that pension fund money is already in investments that include green energy.
Why take it from a place where it is usually smartly invested in successful companies and move it to a government managed fund that will by definition be a far more risky investment?
Lets see the AFL-CIO start this venture with 100% of their own union pension funds. $20 million is a drop in the bucket compared to the billions they have in their funds.