It seems that ethical-investing should be merged with esg-investing, since they appear to be the same thing. However, I am not sure about this because I am not too familiar with the field of ethical investing.
Environmental, Social, and Governance (ESG) is the latest buzzword term for this type of investing. It is probably a more descriptive term than "Ethical Investing" because "ethical" can really mean anything to anyone; "ESG" is an attempt to explain what kinds of things are actually meant. However, this is probably something that will change over time, and I expect that some people will keep adding letters to this as time goes on, to incorporate their favorite pet causes. Other terms that have been used for this are "Socially responsible investing" and "Sustainable investing."
I don't think we want to keep changing this tag with the latest fad terms. I recommend we keep the tag named ethical-investing, as that is really what the investors interested in this are looking for: companies acting ethically, however they define that. The idea is that you care about how the company does what it does, not just their financial performance. This is probably the simplest, most inclusive term for this type of investing.