Goldman Sachs (GS  ) launched its third ESG-focused exchange-traded fund (ETF) this week, with the fund following an index that tracks companies working to reduce the world's carbon emissions.

The Goldman Sachs Bloomberg Clean Energy Equity ETF (GCLN  ) listed on the Cboe Global Markets on Thursday, with an expense ratio of 0.45%.

GCLN follows an index created by Goldman in partnership with Bloomberg which tracks nearly 200 global companies involved in generating renewable energy or infrastructure to support the clean energy industry. The index is weighted to give companies that generate half of their market value from renewables at 60%, with the remaining 40% split between firms that generate 10% to 49% of revenues from the clean energy industry.

The fund's top holdings are American energy services provider NextEra Energy (NEE  ) and Chinese battery marker Contemporary Amperex Technology, together holding over 10% of its weight.

Goldman believes the fund offers an investment opportunity to the multi-decade clean energy transition industry that could see capital of $100 trillion or more. Katie Koch, chief investment officer of public equity at Goldman Sachs Assessment Management, told reporters on Wednesday that this fund is designed to broaden Goldman's suite of decarbonization products for investors, and offers a wider scope into the clean energy industry than currently available, ETF Trends reports.

"We continue to believe that the energy transition is going to be a revolution that is one of the greatest wealth creating opportunities of the next couple of decades," said Koch in a call with reporters, quoted by ETF Trends. "It will have the scale of the Industrial Revolution and the speed of the digital revolution."

GCLN joins the Goldman Sachs ActiveBeta Paris-Aligned US Large Cap Equity ETF (GPAL  ) and the Goldman Sachs Future Planet Equity ETF (GSFP  ) as part of the firm's ESG offerings.

The new fund comes as ESG (environmental, social and governance)-focused equities are delivering strong returns. Last year, 13 ESG-focused index funds that followed broad, diversified indexes of U.S. large-cap stocks saw returns ranging from 25.6% to 31.7%, with seven gaining more than 30%, according to Morningstar.

"We think that this is going to be a great long-term opportunity for investors," Koch added, quoted by YahooFinance. "We also want to emphasize that this moment not is giving a current attractive entry point from a valuation perspective, so it's a really good time to get clean."