I would have to say that climate change—it's a leaders-driven process—was from the outset something that the leaders, the Chancellor, and the Prime Minister intended to have a real discussion on.
Sherpas set up the base camp, but they don't go up to the top of the mountain. That final climb was done by the leaders. The significant issues were discussed and in play by the leaders themselves, and I think the Prime Minister, both in the Canada-EU summit and at the G8, was an architect of the final agreement.