Think your worst ecological sin is the carbon footprint from your RAV4's poor gas mileage? Unfortunately, it's probably not.

Do you think your worst ecological sin is the ugly carbon footprint resulting from your RAV4's rather mediocre gas mileage? Unfortunately, it's probably not.

This video gives a great explanation why. Pardon me while I go give my RAV4 a ... sand bath.

Despite what the oft-ignorant commenters on YouTube may think, the point of the video isn't that we all should stop using dishwashers, showers, and washing machines. It's to raise awareness so that when we hear water conservation measures come up in political discourse -- such as efficiency standards for appliances, or charging for water based on what it's actually worth, rather than how much it costs to extract and distribute -- people will better understand why the discussion is occurring at all.

One of the better comments (by Linnel Gifford-Mahany) said, "Jeez, makes one wonder how many gallons of fresh water there are in the world." Eureka! Just the sort of question that water resource scientists hope to hear asked. The answer is that of all the water on Earth -- including oceans, ice caps, rivers, and subsurface aquifers (groundwater), etc. -- only 0.7672% is usable fresh water (h/t US Geologic Survey). Yes, that's about one quarter of one percent. And keep in mind, the vast majority of even that still has to be treated to make it safe to drink! There is other water available, of course, but it comes at much greater cost; either it must be desalinated from brackish/salty sources, or melted from snow & ice. You've probably heard our glaciers and ice caps are already dramatically endangered, and that the cost of desalination is atrocious -- even the Saudis think it's expensive!

Digging a little deeper, you'll note this isn't solely the individual citizen-consumer's fault. We only account for about 8.5% of use with our Maytags, Whirlpools, and Klean Kanteens of agua. Power plants use 41.5%, and farming accounts for 37%, so they're by far the worst offenders. The good news is that there are real-life, current fixes that could help this problem notably -- they just cost money. Most modern farms are ginormous industrial agriculture operations which irrigate using open, unlined ditches that lose nearly as much water to seepage as they actually deliver to crops. Lining those ditches would make a huge difference. Much of the water lost to thermoelectric power generation could be reclaimed and re-injected into nearby aquifers rather than discharged as as loss downstream to the ocean.

So, take home message: pay attention to water conservation measures -- they matter. Whether it's more water-efficient appliances, more electrically efficient appliances (remember the 41.5%!), or government conservation efforts -- they matter! Ignoring the issue will guarantee a future where the price of water for drinking, cooking, and washing will be so high that all but the wealthy will struggle to pay, just as many of us do now to make our car and house payments.