Dear Maria Augusta de,

Governments should pay attention to the latest landmark ruling this week in South Korea, which found its elected officials guilty of setting weak climate targets. The country's constitutional court has instructed policymakers to set firmer emissions reductions targets between 2031 and 2049. The lack of quantitative goals in that period cannot guarantee a carbon-neutral 2050, it said. 

This is the first time a court in Asia has ruled over the adequacy of a government’s climate action plan, years after Dutch judges told its leaders to slash greenhouse gases faster. Eyes are now on Taiwan, where a similar case is pending review by its judiciary.

Such cases beg a fundamental question: who should be the arbiter of a country's climate ambitions – the (elected) government of the day, bearing the mandate of the people; or the courts, as enforcers of what a nation believes is right or wrong? This inquiry will only take on greater urgency, as more citizens take to the courts to question their government's commitment to confront the climate emergency.

Another offshoot of this debate: legal experts are now asking if progress at global climate talks has stalled, because those with the most clout are not at the negotiating table. Big business and investors must be involved, not just nation states dominating the conversation, suggested a senior judge. Speaking of global treaties, the clock is ticking towards the final round of negotiations for a treaty to end plastic pollution in Busan in November. We speak to the chair helming the talks, Luis Vayas Valdivieso, on how he plans to work out a treaty on time and on target.