How to invest if the only way is ethics

The ultimate aim ao ethical investment is in all cases the same: how can investors combine a desire for returns with a concern for social, environmental and ethical issues?
First, if you have a fund manager settling which firms follow the right ethical standards, you may find that your understanding of these standards differs. To ease up the process, ethical funds are often referred to as different shades of green; the darkest green funds have the strictest ethical positioning and a greater number of, or more stringent, negative screens.
Although ethical funds often underperform other investments, this doesn't mean such funds cannot give back decent returns, or cannot work well in a defensive portfolio, particularly as many green funds steer clear of the banks.