At the time of writing world leaders have just left the COP26 UN-sponsored climate change conference. The Conservative prime minister of the United Kingdom, Boris Johnson, arrived with a team of advisers from Number 10 and his chancellor of the Exchequer, Rishi Sunak, who made a speech on the economics of climate change on the conference's “Finance Day” (Sunak 2021). Sunak says his vision is for the UK to become the world's first “net-zero” financial centre, leading the way in promoting “green bonds” and encouraging firms to be more transparent about their environmental impact. Behind Sunak is a big parliamentary majority without many checks and balances, which should in theory give him and his party scope to articulate and achieve their economic goals. But, despite the UK hosting COP26, Sunak has been accused by Labour and Green Party opponents of undermining the economic drive to prevent climate change by cutting taxes on short-haul flights, and by being lukewarm on transitioning from economic dependence on fossil fuels.

We will never know whether, if Trump had won the 2020 election, he would have flown to Glasgow for COP26, or how much he would have talked about the economics of it while he was there. Although the United States has so far been the worst affected of the five countries in this study by climate change, it also starts from the lowest base of national-level measures to mitigate it. But the proportion of Republican Party politicians who argue that climate change is not happening, or that the policy approach should be nil, is declining. And the Democratic president, Joe Biden, arrived signalling action, with climate envoy John Kerry. Significantly, he also brought his secretary of the Treasury, Janet Yellen. In Congress the recent passage of the fiscal stimulus package shows that Biden may share a two-party system with the British, but he has less scope for action.