 Thank you Peter. I'm going to use a few pictures just to help me in the talk. I think Carl set the issue that we're talking about very clearly, very eloquently. We're moving into a water scarce world and we also are aware that water is vital to agriculture. In fact, on a global scale 70% of all fresh water extraction is used for agriculture, so that's from rivers, from lakes and from aquifers. We know that the demands for water are growing from various sources, household consumption, industry, power generation, even for maintaining ecosystems, wetlands and so on. We also know that the demand for food is going to increase, as Carl also mentioned, not just because of population growth, although that is indeed the main contributor, but also because of rising incomes. Given that agriculture is so dependent on water, that it uses such a large share of these fresh water resources, which is almost entirely irrigation, 99% is irrigation, small amount for livestock. When we talk about the freshwater share, we're not talking about the normal precipitation on soils for rain-fed agriculture. Given that background, how is this dilemma going to be addressed? Of course, it's going to be made even worse by climate change. Does that work? Let me just see. Sorry, did I pass the wrong? Okay, great. Sorry. Climate change is clearly going to have significant influence on water availability. In terms of, for example, snow melt, in terms of river flow, it will affect precipitation, both in terms of the overall quantity, but also the seasonal pattern of rainfall, which is going to have big implications for the way farmers manage their land and pursue their agriculture. It's also, we're told, going to lead to greater extremes in climate. While not wanting to make a one-for-one sort of causation in terms of recent floods, these pictures are from Bangladesh and from Thailand in the last two and three years. It's clear that we are facing into a much more unpredictable climate future. There is a third issue in terms of water, which is, of course, water quality, which has perhaps been the issue that has been uppermost in terms of water policy issues in the European Union up until now. But I'm not going to say anything more about that, just to concentrate on the sort of quantity issues. In terms of areas of water scarcity, this map, I think, will not have any surprises for you. It's clear that some parts of the world are under more pressure in terms of water scarcity or water stress than others. Water stress is a concept where it's really looking at the physical availability of water. That's the sort of blue areas targeted on the map there. You can see particularly North Africa, the Middle East, but also right across West Asia, Central Asia, a little bit of Australia, and indeed, as David already mentioned, South Africa. These are areas that are already under considerable water stress before we even look at future demands for water and the impact of climate change. But then there are other areas where physical availability of water may not be an issue, but economic access to that water, simply the institutional constraints, of course, are enormous and large parts of sub-Saharan Africa and South Asia fall into that category. Sort of the link with agriculture. We essentially have two main production systems. We have rain-fed agriculture. We have irrigated agriculture. In terms of the shares of land, irrigated agriculture has been increasing quite dramatically. The shares are not as such shown there, but essentially around 10 percent of total cultivated area in 1961, about 20 percent of total cultivated area today. We see that the area under irrigation has just over doubled this period, whereas the area under rain-fed agriculture has really not changed very much at all. In fact, it's very slightly decreased. What's interesting, of course, is the relative productivities of these two types of agriculture, where irrigated agriculture, because of the greater security of water supply, is much more productive. So even though it has only 20 percent of the arable of the cultivated land area, it contributes around 40 percent of global food supply or crop supply. In fact, that's made clear on this slide here. The figure for arable land share is a little bit less than the 20. It's 15 percent, but the important figures are these here and in the middle. We see that the share of irrigated land and the production from irrigated land is expected to remain more or less constant, so it's going to grow in line with food demand generally. But we see that even currently, around 60 percent of our total crop cultivation is coming from irrigated land. So we are hugely dependent on that. And of course, the sustainability of that has come under question in many countries. If we go back to this issue of water stress and we just look at the share of renewable water resources, which is used by irrigated agriculture in different parts of the world, and the sort of stress percentage would be around 40 percent. For the world as a whole, over here, it's about 6 percent. So no real stress issue if you like globally. But of course, when you focus in on particular regions and particularly look at North Africa, where even today 170 percent usage of water as compared to renewable resources. So implying huge depletion of underground aquifers and the sustainability that's happening in Belgium, but it's even, of course, more so in these Arab countries. But also look at West Asia, Central Asia, well above the 40 percent figures, which is deemed to be critical. So there are areas of the world where water scarcity is a problem today and going to become more so in the future. What to do about that? We might sort of classify policies under sort of four headings. One is clearly to increase the productivity of rain-fed agriculture, that 60 percent of the land. Secondly, to increase the productivity of irrigated agriculture. We can think about trade between countries that have water services, if you like, and countries that have water deficits. And we could also think, of course, and Carl also made this point about the limiting the sort of potential increase in demand through switches in diets and also through addressing food losses and food waste. So just a comment on each of those in terms of the rain-fed agriculture, which is hugely important because that's where predominantly the poorest small holders live. So if we want to address the poverty issue, again a point Carl addressed in his talk, we really do need to focus on improving productivity and water productivity in rain-fed agriculture. And we're dealing in many cases here with subsistence farmers, not well integrated into the cash economy. So we have to think of ways that don't involve huge expenditures by families that simply don't have that money ready. We can think of issues such as intervention, such as conservation agriculture, agroecological approaches, agroforestry, which is mentioned shown here. We can think of fairly low-key, low-scale ways of water harvesting so that we can actually try to save water when it falls in the rainy season to make use of it in the dry season. And I think an important role is necessary for plant breeding, both conventional and potentially genetic engineering for drought tolerance. If we think of the irrigated technologies, again we can't expand irrigated the area very much. We simply don't have the water in some countries. There are increasing problems with large dams and environmental questions around that. So really the focus has to be on improving the productivity. And there is a good news story here because there is the potential. A lot of irrigated agriculture doesn't operate at very high levels of productivity. That may require investment in upgrading infrastructure. As David gave the example, it will certainly require improved incentives, including possibly water pricing, but also improved management by farmers, switching crops to make sure that the irrigated water, which is more valuable, is used for high-value crops and so on. But also institutional reforms to improve the governance of water. And David gave some very interesting examples related to the tragedy of the comments. And I just had one example you could give many, of course, in this area. But some of you, I don't know, Tom, if you have visited Lake Naivasha in Kenya. But this is a lake in the Rift Valley in Kenya, a little bit north of Nairobi, a very scenic area with quite an important tourist business. But this is also the home of the Kenyan flower industry, flowers as in roses and carnations. And around the lake, you have about 60 flower-growing firms, mostly owned by foreigners, who are producing roses for the European market. In fact, if you buy your Valentine Rose, there's a high probability that it has come not just from Kenya but from this area. The problem, of course, is that there is no regulation of the water use. We have seen a huge extraction of water for the flower industry, which has potentially at least contributed to problems of lowering water level, pollution of the waterways, fish kills, loss of livelihood by other users of the lake in terms of fishermen and so on. I'm not saying this is the only issue because clearly there is climate change. The level of the lake has apparently fluctuated in the past. But it is an example of how we need to have, regardless of where the problem is coming from, how we do need to have some sort of institutional mechanism to regulate and to govern water use in this particular lake, and indeed in other similar examples. Virtual water trade is a concept which emerged in the scientific literature in the mid-90s. The idea here is that we could think of water as being, if you like, embodied in commodities. It's sort of a virtual water. You can see that, essentially, water trade follows flows of agricultural commodities. The big exporting countries, North America, Latin America, Australia, are essentially exporters of water to North Africa, countries of Asia, and China. The concept has been given quite a normative angle in political debate. A lot of people think that there's something wrong with trading water in this way. Either it's because some countries are becoming dependent on imports of water, this virtual water, and that is seen as a bad thing. Or because, for example, when we consume our coffee, we are, in a sense, consuming exported water from countries that perhaps the argument goes could use that water better at home. I think the concept is helpful in focusing attention on water use and the need for improvements in water efficiency. I think as a guide to policy, it can be extremely dangerous. We might debate that in the Q&A, but just to say that that is another way of addressing the challenges of water scarcity in certain parts of the world. Finally, there's huge issues to do, as Carl has already mentioned, to do with addressing food losses, food waste, the question of non-food uses of agricultural resources. We don't have time here to go into these. Some of these issues are addressed in the really excellent Environment Nexus blog, which Linda and colleagues here at the Institute run. Just to finish by saying that I hope I've given some insights into the fact that addressing the water food security nexus is really one of the critical challenges, as indeed the other speakers have highlighted for us in the coming decades.