World's largest wealth fund blacklists four Canadian firms for emissions - Norway’s $1 trillion sovereign fund said on Wednesday it had excluded four Canadian oil and gas companies from its portfolio for producing excessive greenhouse gas emissions, its first use of that reason to blacklist firms.

I thought the Norwegian sovereign wealth fund explicitly avoided fossil fuel investments from the outset, since that would not be a real diversification of the fun, since the money was generated by Norway’s oil proceeds? What does blacklisting these companies do that their own wealth management rules didn’t do before?