 Good afternoon or good evening everybody. I am pleased to be here as a keynote speaker for this IWA World Water Congress and exhibition 2018 in Tokyo. My topic is decision-making with uncertainty. My presentation is, oh sorry, my presentation has two parts. In first part, I would like to show you some aspects of an uncertain world where we live. In the second part, I would like to emphasize the importance of science and technology for our sustainable water future. We have two major changes in the world. One is structural change and the other is unpredictable changes. Now let's see a first example of the structural change, dynamics of population. In 2014, the United Nations reported probabilistic population projections until 2100. Median projection shows our population will reach 10 billion in 2060. This regional projection shows a continuous population increase in Africa. On the other hand, ACM population will start decreasing at around 2050. Japan has already experienced a population decline and after 50 years in 2066, that total population will become 88 million, almost 70% of the current population. In Japan, over the next 30 years, the population is projected to decline in almost all the municipalities. In the white area on the map, the population will decrease by more than 50% compared to the current population. Water supply and sanitation utilities in such areas are facing and will face difficulties to secure required finance and human resources. We need new technologies and policies for operation and management of water sectors for the area. On the other hand, urbanization will pose different challenges to Asia and Africa in particular. According to United Nations data, the world population in urban areas will exceed six billion in the year 2050. I would like to show you an example of issues caused by urbanization by presenting a case of Tokyo in the last 90 years. This figure shows a population density special distribution of 90-20 in Tokyo area, including partly poor neighboring prefectures. At that time, Tokyo area's population was 8.2 million and they had a very high population density district in the center. This is 90-25 after a tremendous earthquake hit Tokyo in 1923. This is the 1947 after a heavy bombing in the World War II severely damaged the Tokyo downtown in 1945. Total population was 12.3 million and the urbanized area started spreading to the suburbs. Demand for water has increased sharply in all sectors, household, industries, and commercial businesses. Now moving forward to 2005, the total population in the same area is 35.6 million. The urban area of Tokyo has spread to a wide area with the creation of sub-urban centers, mainly because of the railway networks. By 2050, the same area's population is predicted to have a small decline to 31.2 million with the same urban structures. So, fat occurred in Tokyo due to the rapid and extensive urbanization. Of course, there were so many problems to be solved, but here I would like to talk about land subsidence related to groundwater. Let's see the history of groundwater level in Tokyo. In this figure, the vertical axis is groundwater hydraulic head in meter and the horizontal axis is in time in year. In the case of Tokyo, groundwater overuse continued until 1965 and the groundwater hydraulic head largely declined as you can see in the left-hand side of this figure. After 1965, however, the groundwater level was improved owing to the control of groundwater extraction by the industrial law and building laws. In this figure, the vertical axis is cumulative subsidence depth in meter. After 1965, Tokyo succeeded in stopping the land subsidence. It is an old story, but a good lesson for other cities in alluvial plains like Bangkok and others. This experience is the reason why Tokyo Metropolitan Government has adopted strict policies for groundwater extraction even now. I would like to move the third structural change, global climate change. Japan Meteorological Agency has three of the batteries for greenhouse gases and passive quotient. In this figure, the vertical axis is a mole fraction of CO2 in PPM. As you know well, CO2 carbon dioxide concentration increased continuously during the last 30 years and exceeded already 400 PPM four years ago. And so, many countries adopted the Paris Agreement under the United Nations Framework Convention on Climate Change 2015. In this figure, the vertical axis is a mole fraction of methane in PPM. Methane CH4 is one of the important gases affecting global climate change and it also has been increasing during 30 years. IPCC has already given a warning on water cycle in 2013. They said due to changes in the global water cycle, the contrast in precipitation between wet and dry regions and between wet and dry seasons will increase. This means that the structural changes in global climate is to create more unpredictable changes such as flooding and CBI drought. We can see how water cycle changed by looking at the annual precipitation pattern in Japan. This figure shows a deviation from the average annual precipitation during 1981 to 2010. The deviation from 1900 until 1970 is as shown in this figure. But it seems that the deviation has been getting bigger since 1970. Actually, Japan suffered a severe drought in 1994 and on the other hand, frequent typhoons are causing many damages in Japan this year, 2018. Also, many areas in the world, Puerto Rico, California, Thailand, France, India and so on, have suffered abnormal weather like severe drought and cloud past very recently. Next, as unpredictable change, I would like to talk about natural disaster. Japan has suffered from many kinds of natural disasters in the past and in the present, earthquake, tsunami, landslides, flooding and so on. I would like to pick up two cases in Sendai City in 2011 and Cove City 1995 to present the damage to their water infrastructure due to large earthquake and tsunami. Sendai City was largely affected by the Great East Japan earthquake in March 2011. The earthquake was followed by a huge tsunami of more than three meter high that struck very wide seashores which are shown by the blue strip on this map. Sendai City was one of the municipalities in the blue strip. Minami-Gamo sewage treatment plant of Sendai City was struck by the tsunami. In this photo, the staffs of the plant were staring at the unthinkable terrible site. The sewage treatment plant was completely destroyed by the tsunami. This is a case of Cove City in 1995. An earthquake directly above its epicenter struck the city. The urban infrastructure was destroyed like this highway. The earthquake severely damaged water supply pipes, especially aged pipes. The damaged point of water supply pipe network reached to more than 1,700. So this is a dual on oxide print. Changes are like waves. We have to move forward to the sustainable water system getting through the changes. As many speakers mentioned in it in the opening ceremony addresses and workshop and key nodes, sustainable water system is the most important subject in order to achieve the SDGs as a whole. So what should we do? Structural change are long-term phenomena and so we can obtain many lessons from historical evidence and experiences from other regions. Unpredictable changes are rare occurrence phenomena and also we have to learn globally from other regions and countries. But that would not be enough. We would also need to develop new knowledge and innovative technology for the future, apart from the ideas on the extension of past experiences or apart from the conventional thinking. The new technology can bring unpredictable development to water sectors and have a great impact on society. We have diverse innovative science and technology related to water. For example, PCR, membrane separation, MBR, earthquake-resistant pipe, biotechnology, image processing, and so many. Here, based on my very personal experiences, I would like to pick up submerged membrane reactor MBR and polymerized chain reaction PCR as two examples of innovations that occurred in the field of water, especially related to IWA and its predecessor association over the last 30 years. Let me tell you honestly about my failure related to technical evaluation on MBR. As you know, well, in the 20th centuries, many membranes were invented and applied to water technologies. Around 1980, membrane separation became popular. In 1988, the concept of submerged MBR was first presented by Dr. Kazo Yamamoto at the Biennial Conference of IWQA, International Water Quality Association, the old IWA, and Brighton United Kingdom. Since it was a new concept, many questions were raised from researchers trapped by traditional ideas. I myself was one of them. In my case, fortunately or unfortunately, I was a colleague of Dr. Yamamoto in the same university, and I questioned his idea and discussed with him directly on biofouling. However, in early 1990s, his idea was recognized as an innovative treatment system and submerged MBR have been widely applied from small-scale on-site treatment to large-scale wastewater treatment over the world. So let's move to PCR was invented in USA in 1985. Soon it became popular for detecting, viruses, bacteria and parasite in water. Around 1990s, a new PCR devices was put on the market almost every month at a lower price. As a young, poor professor, it was hard for me to decide which device to buy and when to buy it. At about the same time, there are very basic controversies about the relationship between infectiousness and positive detection by PCR. Excuse me. By PCR in study group of health-related water microbiology of International Association on Water Pollution Research and Control, IAW-PRC, that is also old name of IWA. At the time, many researchers and I myself could not imagine the real power of PCR. However, after 1990s, PCR has become an essential tool for all biological field and has made remarkable progress. By the way, young members, the new generation of IWA specialist group on health-related water microbiology published a review paper on quantitative detection of human-intric viruses on the journal Water Research in May 2018. Of course, advanced PCR technique was core topics in the review paper. Detection of human-intric viruses is especially a key topic for wastewater reuse. Now, I would like to talk about diversity of science and technology. There are millions of new scientific findings and technology advances around us. We need to raise the antennae high and gather information. And we must cultivate diverse science and technology related to water because turning it into practice could be a key for our solution. We should use the latest technology for our future. As conclusion, to deal with global issues like SDGs in an uncertain world, we need to, firstly, learn not only from indigenous events of individual countries, but from events of wider regions. Secondly, cultivate carefully the new science and technology to solve water and sanitation issues. Suddenly, incorporate diverse science and technology into practice without delay. So for this purpose, communication and cooperation between professionals is indispensable. One mechanism to enable that is the IWA World Water Congress and exhibition here. Perhaps you may find another NPR or PCR in these conferences. Thank you very much for your attention.