Of course, the very existence of central banks is a product of history, and their mandate has evolved over the years as they have responded to market failures.18 In the case of Japan, the Bank's current mandate, as stipulated in the Bank of Japan Act, is to maintain price stability and financial system stability.
The purpose of maintaining price stability is to "contribute to the sound development of the national economy," and climate change, in terms of associated physical and transition risks, is likely to affect such development through prices and the financial system. As such, central banks can address climate change within the scope of their mandate, and this is not mission creep.