The news in the UK last week may have been all about Brexit but at Mipim, the world’s biggest property fair over in Cannes, you’d be forgiven for forgetting it was happening at all (“Don’t say the B word,” joked one investor to me). London’s pavilion was actually buzzing with people checking out upcoming developments and investment hotspots – but perhaps that was down to its prime beachfront position (it also had the best free tote bag).Rather than the B word, the focus this year was on carbon-neutral cities, which is a welcome evolution from the now-tired sustainability chat with concrete goals and proposals. Unsurprisingly, Copenhagen is leading the way, aiming to become a net zero-carbon emitter by 2025. Ambitious? Yes. But mayor Frank Jensen is bullish and insists that local governments like his have a crucial role to play in fighting climate change. Helsinki plans to follow suit by 2035 and Manchester by 2038, putting national government targets to shame.What this means for an industry estimated to account for about 40 per cent of global energy consumption and a third of carbon emissions remains to be seen. But at least in Cannes the mood was optimistic and relaxed. There were even a few people in (smart) trainers – perhaps there’s hope for change after all.