What Influences a Country's 'Climate Policy Index'?

The Lockwood brothers (Universities of Sussex and Warwick) studied factors changing a country's 'Climate Policy Index'. That 'Climate Policy Index' is a measure of how keen that country appears to be to tackle the climate change emergency (https://www.theguardian.com/environment/2022/apr/14/rightwing-populist-parties-blight-climate-policy-study-finds). The Lockwoods studied policies in circa 25 European countries, for over a 10 year period. Predictably, they found that the presence of a right wing populist party in parliament and government produced an average reduction of 25% in a country's 'Climate Policy Index'. EU membership and having a proportional representation voting system, most reliably lessened the impact of these right wing populists on that measure. Having said that, there is a world of difference between having appropriate policies and fully activating them! That can be seen, in recent developments in the US (https://www.theguardian.com/us-news/2022/apr/14/gina-mccarthy-departure-white-house-climate-adviser). Delivery is everything!