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Friday, June 1, 2012

Footprints, Aquaponics, and "Being Green"

The conversation these days is full of talk returning to whole-grain foods and "being green." Yet it's not always clear what advertisers and green activists mean by "green." There are three different views of what "green" means:
  • Reducing our reliance on petrochemicals, our carbon footprint
  • Reducing our consumption of natural resources, our ecological footprint
  • Reducing our consumption of fresh water, our water footprint
Most folks focus simply on saving fossil fuel, the carbon footprint portion of the equation. This becomes contentious because reducing fuel use is often equated with changing existing market models. If you're in mixed company (e.g., liberals and conservatives) arguments will likely break out where those benefitting from the status quo and those advocating for change coming to near fisticuffs over the science behind "carbon footprint" and global warming. Typically proponents of the status quo claim "green" scientists and liberals are idiots. The UN target is ~2.0 metric tons of carbon per person per year. The current world-wide average is ~4.0 metric tons per year, and the average person in an industrialized nation produces more like 20.0 metric tons per year. Oops.

A more comprehensive measure is ecological footprint, how many "worlds" worth of earth's resources we consume, or how many "worlds" worth of earth's resources would be consumed if all earths inhabitants lived like us. The science behind ecological footprint isn't as likely to be challenged, because it is less well-understood. Besides, the slogan "Reduce, Reuse, Recycle" is pretty catchy and obvious. We are "sustainable" if we use only as many resources as the earth can renew in a single year. Currently humans worldwide consume resources it takes the earth 1.5 years to produce.

More recently the United Nations has begun focusing on water use. When it comes to water, there is no fossil fuel resource we can tap. The fresh water available is a finite resource, and mankind is not doing a good job of managing this resource. An old saying goes "Beer is for drinking, water is for fighting." Many of us forget that water is limited because all we have to do is turn a knob and water gushes forth. But lack of water is the natural "disaster" responsible for the greatest number of premature deaths across the globe.

When I grow food using aquaponics in my own backyard, I am arguably saving fuel relative to what I'd "spend" driving to the store. But as researchers have carefully measured and I've observed, aquaponics uses only 1/10th the water required for traditional gardens.

Aquaponics might not strike everyone as sustainable, since some of the components must use electricity or at least be made from relatively modern materials. However once you have your infrastructure in place, aquaponics is one of the most sustainable or "green" ways to grow food, particularly from the standpoint of saving water.