 Here's our atmosphere, one of the great global commons. You're using it right now, breathing in and breathing out, and we use it collectively as a sewer, dumping our waste and our pollution into it, hoping it'll just go somewhere else. And for most of human history, that's been a good assumption, there haven't been too many of us around, but now there are 7 billion of us, and the problems are accumulating. And the mother of all problems is climate change. We've had 20 years now of UNFCCC conferences, and over those 20 years, emissions have continued rising and rising, interrupted only by the financial crisis. So one question is, are there other approaches or new ways of thinking about this? Now we've had a big atmospheric commons problem, the Montreal Protocol. Here in blue, you can see the hole in the ozone layer emerging from 1979 to 89 on the top, and stabilizing from 2006 to 10 on the bottom. And we got to grips with this, because the Montreal Protocol used the forces of trade and of technology to grapple and to bring together a creative coalition of business and governments. So can we cut and paste to climate change? Well, unfortunately not. Climate change is much harder, because greenhouse gases are a pervasive feature of all of our production and consumption, and the incumbent fossil fuel players don't have an easy, quick, technological fix that they can move to, and hence it's a business threat in their fighting climate policy. There are two fundamental things we need to do, in my view. First, it's about money. Clean energy remains more expensive than dirty energy in most places most of the time. And the second is to overcome the free riding problem that we have. Most countries feel that they have an incentive to hold back and wait for others to move first. Now on the first point, there is some very positive news. Research in labs around the world, including at the Oxford Martin School, here are solar perovskites and electric vehicles, have been bringing the cost of clean energy down quite rapidly. But these cost declines are very positive, and there's another positive feature of them, which is that we've learned just last year that the spillovers, the economic spillovers from clean technology are much higher, 40% higher than the spillovers from dirty innovation. So clean ideas beget more ideas in society than dirty ideas do, which is a justification for further public support. And we'll need it. Joint work with economists at Harvard and the LSE shows that we are locked in to a fossil fuel society, much as we are all locked in to using QWERTY keyboards, designed to prevent jams in typewriters. We don't use typewriters now, but we still use the QWERTY keyboard. The fossil fuel system is the same. There are all sorts of lock-in and path dependencies that mean that researchers in the dirty area have a greater payoff than researchers in clean. And we spend in 2012, it'll be less now, between US$600 and US$700 billion a year looking for fossil fuels versus US$350 billion on all forms of mitigation, including renewables and other clean technologies. So there's a big bias in the system. And you may well ask, why are we spending US$600-US$700 billion looking for more fossil fuels when we already have many times more than we can ever afford to burn? This shows the carbon embodied in fossil fuels versus the carbon that we can afford to put in the atmosphere to stay within two degrees. We do not need to be spending money looking for more. So the good news is, the costs of clean are falling fast, but they're not falling fast enough. We will see parity under various assumptions, but they're actually fairly regular. Work at the Oxford Martin School suggests parity at around 2030 at scale deployment. But this is not fast enough for the climate. We need an acceleration. And my view and my proposition is that we need a deal, a creative coalition, an international deal between the key players on renewable energy, research and development and innovation to bring these costs down. This is a first order feature of the problem. And I think such a deal is perhaps more feasible than the deals we're trying to strike, which have to balance ambition, getting people to be ambitious enough, participation, getting the right players in the room, and then compliance, making sure that people and countries live up to their pledges. With research and development, more of the benefits stay at home. And so the free writing problems are not as bad. You might create new industrial clean energy champions. And if we could design a club, like the World Economic Forum, like the G20, where people wanted to join, where the benefits of membership in terms of technological transfer, favorable trade regimes, et cetera, meant that you were better off in than out, and I think we could really trigger a big pulse of support on clean energy innovation that would pull the costs down. And if we did that, we would see the herds of the capital markets shifting the financial flows away from wasteful spending on fossil fuel assets that are just going to be stranded and in towards the newer markets of the future in clean energy. So that's my suggestion for going some way towards helping resolve the great global commons in the atmosphere. Thanks.