BlackRock, the world's largest asset manager at $4.3 trillion, is urging investors with a social and environmental bent to go public.
Going public means two things for BlackRock: using public securities such as stocks and bonds and also being vocal as an activist investor.
"Impact investing has historically been very associated with venture capital and private equity. If we're thinking about the whole investor and they want to address climate change, then why should we ignore public equities, fixed income and alternatives?" asked Robert Morris, a member BlackRock's strategic product management group, which helps the firm's clients align their ethical goals with investments.
Morris also encouraged clients to be public with those investments. "It's important to make this visible, and activism is also critical for it to actually have an effect," he added while speaking on Tuesday at the New York Society of Security Analysts' Sustainable Investing conference in New York City.
BlackRock has a 20-person team focused on so-called ESG investing, which stands for incorporating environmental, social and governance criteria as part of investment research.
Morris said the firm is working to expand public market products for clients in three areas: stocks, bonds and infrastructure.
In fixed income, BlackRock has focused on so-called green bonds, which are issued by companies and international organizations and only back environmentally friendly projects. He called green bonds a "fascinating market" despite its now small size and often low returns.
"It's really about incorporating that impact dimension into their allocation decisions," said Morris. "What we're trying to address is 'what else do you want to do with your money?' What is that extra financial goal that you have?'"
—By CNBC's Lawrence Delevingne.