Nest, the UK’s £12bn national pension fund, is shifting almost half its money into “climate-change aware” investments and pledging to make its entire portfolio carbon-neutral by 2050.

The fund, which forms the backstop of the country’s quasi-compulsory workplace pension system, said it will immediately begin divesting from companies involved in thermal coal, oil sands and arctic drilling, and promised to have divested entirely from these companies within five years.