Besides their core portfolio, you can also opt to invest in sustainable ETFs. These are portfolios that are focused on environmental, social, and governance or ESG. These ETFs provide similar returns as a traditional investing portfolio, but gives you exposure to companies that are sustainable.
Acorns uses iShares to build their ESG portfolios. Each company in the ETF is scored by MSCI, a research and data company that uses a companies response on big issues like climate change.

Acorns offers four categories in their sustainable portfolio: Moderately Conservative, Moderate, Moderately Aggressive and Aggressive. While the composition is similar to their core portfolio, Acorns sustainable portfolio offers more variety of ETFs.