BlackRock is a very simple business to understand. First, they only investment money on behalf of their clients and they take investment fees for making decisions on behalf of their clients (investing their money).
They break the business in to two parts:
Alpha: old school mutual funds, new school quant funds, real estate etc. Anything where managers get paid big bucks to make investment decisions on behalf of clients.
Beta: passive investment vehicles that blackrock tries to deliver for the lowest price with lowest tracking error (i.e. deliver as close to what the index returns as possible).
What BlackRock is doing here, is a VERY, VERY big deal. They are allowing clients to now pick passive investment strategies which exclude coal or other businesses that people find morally objectionable. What that means is that if you care about the environment you can move your money to these new passive investments. As more and more people do it, it will decrease demand for equity in those companies and increase their cost of capital.
On the active side, they already had that feature, and many of their clients already ask BlackRock to exclude investments from their active portfolios and were willing to accept less return. (BlackRock has offered that for a very long time).
I find very few things interesting that asset managers do, but I am going to look at all my passive investments and try to get them moved over. I bet passive funds without coal etc. will outperform while more and more people move money from vanilla S&P500 to S&P500 without coal.
Eventually those coal companies may fall out of indexes all together which will really increase their cost of capital.
Brilliant move by Fink, and I applaud it.