Yukio Hatoyama is still one week away from becoming Japan’s prime minister – the first from the left-leaning Democratic Party of Japan – but he is already making waves internationally. Last month, electioneering comments about Japan’s unequal alliance with the US sparked concerns – later doused by Mr Hatoyama – that DPJ victory would undermine US-Japanese relations. On Monday he made another splash, setting a far more ambitious target for cutting greenhouse gas emissions than his Liberal predecessor, Taro Aso.

Mr Hatoyama’s pledge to cut emissions by 25 per cent (from 1990 levels) by 2020 – rather than the 8 per cent proposed by the LDP – is a welcome move from the leader of a what is, despite anaemic growth, still the world’s second-largest economy. It burnishes Japan’s credentials as a responsible member of the global community and marks the DPJ as both more idealistic than the LPD, and less in hock to business.