According to a recent Forbes article, it's grown by 97% and the dollar value has grown from billions to trillions.
Many investors previously feared they would have to sacrifice performance and potential return if they chose to focus on sustainability. More investors are realizing though, that companies focused on sustainability are well-managed companies that look at the "big picture". These companies are managed with a long-range view toward environmental and social issues.
Forbes addressed the issue of integrating ESG factors in the valuation of a particular company and discusses how investors can evaluate and compare different asset managers' approaches.
You can find the full article here.