Passive income: NO

Starting a sustainability consulting side hustle for small businesses can potentially lead to earning passive income. However, achieving passive income solely from this hustle is less common and typically requires significant setup and systems in place. Automation tools, standardized processes, and outsourcing tasks can help streamline the business and make it more passive. While there are success stories of individuals earning passive income from sustainability consulting, it is more likely to require ongoing effort and active involvement to maintain and grow the business. Setting up this side hustle can range from $500 to $2,000, and it may take around 6 months to 1 year to start seeing a profit.