| Good morning and welcome to yet another lecture in Environmental Science. |
| I don't think I'm telling you a secret when I mention that water is a big worry here in Australia. |
| The stuff is scarce. |
| Perhaps that's why we drink so much beer, eh? |
| Seriously, though, a safe and reliable source of water is one of the great concerns of people everywhere. |
| Moreover, as the world population grows, |
| the pressure on existing water supplies grows greater and greater. |
| Think about it. |
| Our economic system demands that there be more and more consumers. |
| The growing number of people has been tied to climate change, including droughts. |
| So more people means less water. |
| But our economic system demands a high birth rate. |
| Forget about oil. Soon enough you will see wars for water. |
| Mark my words. |
| But today, I'm going to confine my remarks to Australia. |
| As noted already, here down under, the water supply is extremely scarce. |
| The only drier continent is Antarctica |
| and remember, no one really lives there anyway. |
| Moreover, in recent years, the wind patterns have changed. |
| Rain that used to fall on the country now falls out to sea hundreds of miles to the south. |
| Now, when I speak of people needing water, most of you probably think of drinking. |
| Certainly everyone needs water for drinking. |
| But surprising as it may sound, |
| drinking is not anywhere near being the main use for water. |
| Most water is actually used for washing. |
| When you take a shower, you probably use well over a hundred litres of water. |
| Every time you flush your toilet, that's about 8 litres. |
| But most people drink no more than two litres or so per day. |
| So, where to get water? |
| It could be obtained from rainwater, |
| but often rainfall consists of other harmful pollutants that evaporated with the water. |
| In fact, acid rain, an intense example of this, |
| causes harmful effects on the wildlife of the habitat on which it falls. |
| Water from underground could also be used, |
| though it is more difficult to contain |
| and often must go through an extensive cleansing process. |
| The purest water is found in rivers, creeks, lakes, and dams. |
| And, sad to say, Australia has precious few of these. |
| Really, how many of your home towns have rivers? |
| Year-round rivers, I mean. |
| The soil tends to be sandy, so water soaks into the ground. |
| Many places are rocky too, |
| so 87% of the rainfall is lost to evaporation. |
| That's almost twice the evaporation rate in my native Canada! |
| Speaking of rain, we already heard how rainfall is diminishing here in Oceania. |
| The quantity itself isn't the only problem, either. |
| Going back to the problems with obtaining rainwater, |
| a further problem is that rain is a useful source of water only if air pollution is fairly mild. |
| Again, you're in a situation where you can't win. |
| You need water where most people live. |
| People tend to build cities where rainfall is adequate. |
| But then modern cities tend to feature polluted air |
| which renders the rain far less easily usable. |
| OK, let's take a look at the table here, |
| you'll see it showing the relative pollution of rainfall in the world's cities. |
| The more people, the dirtier the rain. |
| This is becoming a huge concern for people in the West, |
| who want their water to be pure and safe. |
| Though reliable drinking water is important everywhere, |
| the concern in the West is reflected in all the government regulations and political campaigns aimed at solving this problem. |
| In contrast, there are not as many demands made on the governments in Asian and African cultures to improve the water, |
| as their focus is on other issues. |
| Now, whatever the source of water, |
| we can never afford to forget that all water is highly vulnerable to contamination. |
| Whether we're getting it from the ground, from bodies of water, or rainfall, |
| it is susceptible to a variety of toxins. |
| In fact, that's why we clean it before using it: |
| water carries with it filth and dirt. |
| This problem shows up in a number of different ways. |
| As humans and all other animals need water to survive, |
| it's no surprise to us that one of the most important domestic uses of water is for drinking. |
| Yet if you have old-fashioned lead pipes, |
| you may slowly be poisoning yourself by drinking that nice clear water. |
| The industrial pollution, farm chemicals, and leaky landfills |
| are well-known sources of contaminants as well. |
| So what is being done to ensure we Australians a safe and steady supply of drinking water? |
| There are a lot of initiatives that make admirable efforts to remedy this issue. |
| We'll be talking about this when we meet again on Thursday. |
| But, as a preview, |
| I can tell you that so far the amount of real solutions that have been produced is not nearly adequate. |
| Traditionally, we've been very free in this country. |
| That means that every person and every province tend to go its own way. |
| So the mechanisms for water management are, in a word, insufficient. |
| To begin seeing how this is so, I want you to read something before our next class. |
| Though a lot of previous data on water usage and water management are inconclusive |
| and have thus caused quite a concern, |
| we can learn a lot from the contents of reports written on the subject. |
| The basis for the government's water policy is the 1989 White Paper |
| reporting on "Water Use: Present and Future". |
| If you compare the numbers offered in the paper with those in the text, |
| you'll find that the report is rather untrustworthy. |
| Truth being told, I'm being too kind when I say that! |