A big event is all about the guest list. While the ‘who’s in, who’s out’ speculation around COP27 can feel like a distraction from its all-important mission, there’s good reason why we’re so invested in our leaders going. UK prime minister Rishi Sunak misread the national mood when announcing he would be skipping the UN climate conference to focus on domestic issues last week. The new PM now appears to be manoeuvring into a u-turn. Simply put, the summit is not just a chance to ramp up commitments on climate change \- the biggest issue of our times. It’s also diplomacy on a grand scale, giving…