Figures from Lipper suggest ethical equity funds under-deliver against their sectors.
However, it is important to remember that this screening is what the underlying investors want, Hollands adds.
Mark Robertson, spokesperson for EIRIS, the not-for-profit research organisation, which covers about 3,000 companies globally, and funds in the UK, Netherlands and France, argues that UK retail assets under management in ethical investments continues to climb. This currently stands at about £10bn.
In recent years, this has been driven by factors such as the credit crunch and the financial crisis, which caused investors to reconsider the nature of risk.
"It made people think how sustainable their investments were, in all senses of the word," Robertson says.
Another driver is the UN Principles for Responsible Investment (UNPRI). Although not prescriptive per se as a set of guiding principles, it is being used by an increasing number of institutional investors, Robertson suggests.
In part, this is about client demand, but it is also about seeking other ways of understanding risk, and about understanding ESG.
EIRIS has also tracked sovereign bonds for the past decade. This has come to the fore through events such as the Arab Spring, which caused bond investors to think about socially responsible investing (SRI) and ESG.
Robertson says the principles-based approach of UNPRI is positive, precisely because there is no such thing as a set of default screens for ethical investors to rely on.
For example, the particular approach that a fund takes may depend on its investment style.
He says: "There is a broad range of investment ideas out there."
UNPRI also works well as a first step for investors who may be new to the area of ethical investing.
For example, while Nordic pension funds have been investing in this way for years, others are just starting, he says.
Robertson avoids the use of the expression ‘dark green/light green' because he says that is more about the retail market, and because for some investors it may be that light green is more appropriate in any case.
Anecdotally, EIRIS has seen fewer ethical fund launches in the past year. However, there seems to be a steady increase in the flow of money targeting ethical products.