I have just come across a very interesting set of statistics while reading The Economist (“For Want Of A Drink,” May 22, 2010, at 52). I was sharing this with some folks this morning as we were talking about the BP oil blowout near the Gulf coast.
Water is remarkable. Without it, life as we know it ceases. It has the physical property of becoming *less* dense as it cools allowing its solid state to float on its liquid state. Someone could correct me, but I believe that water is the only significant compound that does that. Water is, literally, "vital" to human existence. And with more humans on the planet, we need to find more water.
Everyone in grade school learns that the surface of our planet is made up of mostly water. There’s a lot of it – a lot! Strictly, it is a practically non-renewable resource as water is not easily made or unmade. While water may exist in several forms (ice, liquid, gas), there is only so much of it on the planet. We may get some deposits in the form of meteors, but we also lose some water to space, as well.
So let’s break down our water. Of all the water on our planet, 97.5% of it is salty. Let that sink in a bit. That means of all the water on our planet, only 2.5% is ‘fresh’ water – only two and a half percent. Water can be “de-salted,” but that is not easy and takes a lot of energy.
Now of that 2.5%, 69.5% of fresh water is locked up in glaciers and permafrost. So, of the fresh water that we do have, nearly seven tenths of it is not moving. So, of the 2.5% of all the water on the planet, only a bit over 30% is not locked up solid. Of the remaining non-solid water, a bit over one percent is on the surface – the rest of it is underground. Let me restate that; of the non-solid water, one percent is above ground and the rest is underground.
So the underground water is somewhat accessible and we get to that by sticking a hole into the skin of the earth and sucking it up or waiting for it to bubble up. We call those wells. Drilling for oil is roughly the same idea. Here’s our problem – most of the ground water that we tap in these ‘aquifers’ is being used up faster than it is being replenished by trickling back in. At some point in the future, all things being equal (yes, that's quite an assumption), we will suck the ground dry.
Let’s return to the surface. Not all is as it seems there. For of the 2.5% of the water on the planet that is fresh, and of the one percent of it that is either not locked up solid or buried in the ground, you are left with what is called “Surface and Atmospheric” water. As it is titled, ten percent of the S&A water is floating in the air. The rest of S&A water is divided up this way: 70% in lakes and rivers, 20.7% in soil moisture and wetlands, and under one percent is locked up in plants.
So the big picture to take away from all of this is that while the Earth has lots of water, it turns out that only a very small amount of it is easy to get at. By the way, we don't like it when we drain out big collections of water. The Russians have done a rather compelling job of emptying the Aral Sea and nobody else is happy about that.
So what’s the other side? Of the fresh liquid water from rivers, lakes, and groundwater; 67% is used for food production, 20% is used for houses and industry, 10% is used for power generation, and three percent just evaporates from reservoirs.
One of the problems with water is that it is not super easy to recycle it. A lot of farm and industrial water is used and then tainted with some nasty chemicals – it takes energy and/or time to clean it up. So that fresh water is both “used” and “consumed.” That is, being “consumed” (tainted), it can’t be released back into the general supply. We tried doing that for a while and then found that rivers were catching on fire. So that didn’t work out for us very well. We do treat sewage water, but only to release it *mostly* cleaned up into the general supply and let other biological processes clean up the rest.
I was born and raised in Southern California. As I learned about the history of my state it turned out to be dominated by water politics. How to get water from wet parts of the state to dry parts and, if at all possible (and it was) to ‘steal’ it from other states. Water is a Big Deal in California. My father was employed by the Water Resources Control Board in their huge California Aqueduct project. In a very earlier similar project, California actually accidentally created a huge lake in the southern interior now called the Salton Sea because of a water transportation accident. Lots of people need lots of water and California - especially the southern part - is defined by imported water.
Water, on a world-wide scale, may become one of the dominant political footballs of the next century just as it was in the last century in California. It will be an interesting issue to monitor.