By: Zhi Chang Joo Hu
Water is without doubt one of the most important elements on earth. Without it, we could not even live. In fact more than 70% of our body is water. In Los Angeles, we take water supply as granted. But what if it isn’t? What if the water that comes out of your tap travelled hundreds of miles for you? Sadly, thats the reality. Most of our water supply is not local (LADWP 5-6) but rather imported given its scarcity (see graph below for sources) . If this is not sad enough, things could get even worse.
Before reaching to conclusions, here is a simplified physics lesson of what might happen:Since the industrial revolution, mankind has started to build fossil fuels as a cheap source of energy. Thanks to this revolution, technology and development has advanced incredibly, but -as most of the things in the world- progress is not free. As the graph below shows -better known as Keeling Curve- the concentration of co2 in the atmosphere has increased levels never seen before. As a result of this, more of the radiation is being trapped by our atmosphere, radiation that would otherwise bump back to the space. As the earth warms, the whole earth will change, given that the sun is its only source of energy -in the form of light and heat-.
The latests simulations, from IPCC (Intergovernmental Panel on Climate Change) Fifth Assessment report of 2013 (Disclaimer: the reports are still tentative as of 12/02/2013, and thus I am not allowed to cite any source within the report. This data may change) estimate that there are some areas that will get more rain, while others will get less. Los Angeles is right between that line. In other words, there is 50% chances that there will be more rain, and equal chances of it getting drier -added to the fact that there is a high rain intermittency in Los Angeles-. We cannot risk to gamble.
It is then time to start taking advantage of our water resources in a more efficient manner and be more sustainable about it. By reducing our water usage through more water efficient appliances and by taking advantage of rain water through run off capture it is possible to reduce our water dependency in the short term. In the long term though, it would be necessary to increase our now marginal -only about 1-2%- usage of recycled waters (LADWP) and change the vegetation for native species, as they are more adapted for the water necessities of the region (see graph below).