As the US trembles in fear at the possibility of paying the same price as everyone else for things the main focus of everyone's attention seems to be on people's oil dependence. The main focus of oil usage is cars, which makes sense since that's the only time we really come to terms with the stuff we're paying for is oil. Of course we know that planes need fuel, but it's not like we have to stand at the side of the plane and fill it up trying not to get that painful last drip on our shoes. When we fill up our cars we can smell the stuff, when we tinker with the engine we get the stuff on our hands. Cars are oil!

Of course we all know that oil is used everywhere, but we don't feel like direct consumers. We don't even really associate things like flying with fuel despite the fact that we all wonder if we'll be one of the passengers dumped on a tropical paradise full of polar bears and psychos making our life miserable or if we'll die a much quicker death in the intense heat of aviation fuel burning all around us.

Of course recognising the things we use oil for is only the start of the challenge, finding an alternative comes next. So imagine my thrill last week when I heard some figures about a very popular item which has a big oil impact and a simple alternative. In fact, the alternative is cheaper and easier too. This magic item I talk of? Water!

Apparently sales of bottled water are currently at 89 billion litres globally. Bottled water! Let's do a quick look at some of the oil you'll need in that process. First we need to collect the water, we need to build a plant so lots of resources and industrial machinery. That plant need staffing too so we've everyone's daily commute there. The water needs bottling, we'll need those shipped in from somewhere, ideally straight from the factory with all it's resultant burden but possibly they go into warehousing first. Most water bottles are plastic but the glass bottles with metal caps need melting and molding too, plus we've got mines to keep running and ship raw materials from.

Once we've finally got all this water into bottles it goes into storage, then it's shipped to another warehouse, then with any luck it gets shipped to the shops. Now any leg of this journey could be a hefty distance. The US drinks 13 billion litres of water by themselves, this results in them importing nearly 1 million tonnes of water. Not exactly a few row boats crossing the Atlantic there then. And of course not all that water is drunk in New York so it needs to move about the rest of the country too.

Now tap water - you already have the infrastructure in place so there's no extra burden there. The pumps run a little more maybe but the load is shared so you can sleep pretty easy about that. Maybe some pipes wear a little more and need replacing a few weeks sooner but you're still not exactly tearing up the planet.

Drinking tap water instead of bottled could dramatically reduce the oil usage of most western nations, potentially reducing the cost of oil and therefore nearly every product we buy. But despite these savings we hang onto cars where we feel our alternatives are much more limited. Not completely obviously, but good alternatives are hard to find - the carbon footprint of a hybrid is significantly higher than a standard car yet the fuel savings are so small you need to drive it for many extra years to break even. Public transport will be caught in the vicious circle of nobody using it due to lack of funding and no funding because nobody uses it for years to come.