Despite being the world’s largest pension fund and becoming recently more heavily involved, Japan’s Government Pension Investment Fund (GPIF), the 1.4tn in-assets fund, is still starting to take action.

A top executive at the world’s biggest pension fund, Hiro Mizuno, chief investment officer of the GPIF, has expressed doubts over green bonds, indicating that “they are more costly and complicated and cumbersome” for issuers, and for investors “it’s a bond with the same credit rating and the same interest rate — but [investors] have to live with less liquidity.” Mr. Mizuno added that to catch on, green bonds have to be effective for borrowers.

Mr. Mizuno had already branded green bonds a “lose-lose” proposition at a UN conference in Paris last November. Those remarks then set a negative tone for the market, given the significance of Japan’s Government Pension Investment Fund being an opinion leader in global financial markets.