 Well, I think first of all, there are so many different forms of adaptation and so many strategies in so many sectors. So one of the biggest challenges is just how complex it is. I would say a second challenge is there's never going to be enough money. I mean, even now, most of the climate funds are going for mitigation and we're so far off what we need for adaptation, maybe only 10% of the money has been pledged. I think a third one would be that we've been focusing on adapting to impacts in a particular place and in fact, most places are vulnerable to changes in other parts of the world. So we haven't looked enough at how to, in a way, sort of buffer ourselves against climate changes in other parts of the world. And I would say a sort of a fourth challenge is the limits to adaptation. We could be facing warming that's so great up to five or six degrees if we don't control our emissions that we may be looking at loss and damage rather than adaptation because people aren't going to be able to adapt to the stresses like it's going to be too hot for certain crops, countries are going to be flooded and so maybe there's some places where we can't even adapt.