But for now, cautious optimism prevails. He is trying to suppress his excitement about the Obama presidency. "I am anticipating the US having a bash not just at repairing the damage from the Bush era, but shooting for real genuine leadership, which is what the world needs." The credit crunch has thrown up new possibilities as well as problems. "A couple of days ago, the ExxonMobil chief executive came out in favour of a carbon tax," Leggett points out.