Clean water, or lack of the former, is not the sole reason for deaths in what is mostly the developing countries. Yes many millions died - but remember that the majority didn't die due to a direct dehydration impact, most will have died due to secondary effects of the water, such as Cholera. The death toll is not completely due to lack of clean water, but more the fact that developing countries can't cope with the diseases it brings. That's why hardly anyone in developed countries dies of diarrhoea. Admittedly, there is no problem if the water is already clean. But the real killer is not the water; it's the medical capabilities of the countries. I'm not going to say those 1.5 million people would have died in another way anyway, but I'm certainly implying it. It's terrible that people die, but unless charities help or the country improves, people are going to die anyway.
I agree that water is a big upcoming issue, although I have a certain amount of faith that water treatment methods and costs will improve; and be more widely spread in the future. But it's uncertain, so water is a "uh oh", but more so than water for me is the land issue. The human population is increasing, as the land available to us decreases (due to rising sea levels, global warming). It's too late to stop Global warming by now, and it's hypocritical for MEDCs to say to NICs like china "you're polluting the environment with your industrial revolution", when we ourselves had one. Even if we did force restrictions, they would either be ignored or be bought out with money. So that leaves the world with an increasing population, with basic food, water, employment needs, with a decreasing amount of lands. Even an optimist would be worried about that. As I see it, this will cause an even greater difference between MEDCs and LEDCs. I definitely see big, rich countries threatening and buying out land, even wars starting over land. Even without all of that, there is the basic population problem that the human population has to start eventually falling, and when it does I see billions dying every year. There's not much that can be done to prevent this now, and for me it kind of puts water problems in perspective. Although I'm not saying that lack of clean water is not a terrible, horrific situation. There’s just a general feeling of a very dim future: we are lucky to be alive in what is probably the best time for human life yet, and will be for a few centuries. Although if you look at the situation: we are not only mainly disregarding poorer people now, but we are ruining the lives of future generations. Perhaps I make it sound worse than it will be, but it’s still a problem that Governments do not even recognise, let alone tackle.