Once, the key question for pension funds considering ethical investments was not how much of their fund they should invest in socially responsible assets but whether they should do so at all.

Now, in greener times, some schemes, such as the UK Environment Agency’s £1.37bn (€1.8bn, $2.7bn) fund and ERAFP, the €4.8bn French public service additional pension scheme, invest all their assets in socially responsible vehicles.