Don’t assume mutual funds meet this standard just because they’re designated as “socially responsible.” Instead, run the funds through an online tool created by As You Sow, a group that presses for corporate responsibility. The tool makes it easy to spot fossil-fuel exposure and identify greener options.

That brings us back to the carbon that may be hiding in your mutual fund or 401(k). One of the pioneers in the divest/reinvest movement is the nonprofit foundation As You Sow, which works with shareholders to improve corporate accountability. It has developed a tool that finds the carbon in thousands of the most common mutual funds and retirement plans. It does the detective work instantly and cost-free with up-to-date data.

Using 401(k) retirement plans as an example, As You Sow’s explains “those funds can invest in a wide array of securities, and it’s not always easy for investors to investigate what’s inside the funds they own. You can spend hours poring over mutual fund prospectuses, and still not fully grasp everything your 401(k) is invested in. Your retirement money may be invested in economically and morally risky fossil fuel companies.”