We’ve heard of storing carbon in old mines, in deep-down porous rock formations, under the ocean, even in concrete or nanomaterial. But here is one I hadn’t heard before…storing it in dirt – particularly, farming dirt specifically for CO2 storage. A new type of farming is being explored by scientists at the US Geological Survey and UC Davis, a type of farming that will produce soils that can store carbon dioxide.

Really, it isn’t so much farming as restoring native environments that naturally like to store CO2 – wetlands with peat soils. The notion actually takes a lot of the high-tech out of the equation, and helps us store CO2 by bringing us back to our roots, literally.

The scientists started a pilot project a few years ago in the San Joaquin Valley River Delta that included planting up a bunch of wetland plants in 1997. By 2005, 10 inches of peat soil was produced through the plants growing, dying, composting, and regrowing. The scientists’ experiment has shown that up to 25 metric tons of CO2 annually can be stored in an acre of peat. It would take a whole lot of acreage, but the scientists say that if California restored all the subsided lands in the Delta and made them “carbon farms,” the lands could store enough carbon to equate trading all the SUVs in the state for hybrids.

While that might sound attractive, there are some serious issues. The wetlands could release nitrous oxide, which is worse that carbon dioxide, as well as methylmercury, which is basically poison for mammals. Measurements of released methane varied widely during the pilot project, and they didn’t measure release of nitrous oxide at all. So the project could set us back, rather than launch us forward.

Despite the risks, the scientists have been awarded over $12 million to test the research on 400 acres in the Delta.

I dig the idea of restoring the landscape to what it once was, and benefiting from the natural occurances. Yet the possibilities of mucking things up worse than they are is not such an attractive notion. While California needs to cut emissions back to 1990 levels by 2020, this potentially a risky way of doing it, instead of, say, actually swapping all the SUVs in the state for fuel efficient vehicles… The concept definitely has some pros and cons to be carefully weighed as the experiment progresses.

Via Cleantechnica; ENS newswire; photo via kacey

My first reaction when I got the press release for the NatureMill indoor composting machine was to laugh. Why would anyone need a $300 machine in order to do composting? All you need is a corner of your yard where you can set a compost pile and let the worms and bugs and micro-organisms do what they do. Composting works just fine without a machine to run the process. Isn't this just another case of someone trying to sell an overpriced and unnecessary gadget with a little bit of “greenwash”?

Then, as I thought about it further, I realized that not everyone has a yard where they can have a compost pile. Apartment and condominium dwellers may not have a space where they could even have a compost pile, or, if they do have a yard, association restrictions and proximity to neighbours would prevent them from having an exposed compost pile. Offices may also have sufficient organic waste that composting would be a reasonable thing to do, but again, don't have an available space where they could put the materials and allow natural composting to take place. Despite these restrictions, someone in any of these circumstances might nevertheless want to compost their organic waste. And no one wants to have a compost pile sitting around in their apartment or office. So, perhaps there is a place for this machine, for some people's needs. As a machine, it only needs about $0.50 worth of electricity per month to operate, according to the manufacturer. And it is small enough that it can be installed in an under-cabinet configuration.

It would still only make sense for users who had someplace to use the compost they produced. There's not much point in composting the waste unless you can use it for a garden or some other useful end. And if it can help support more urban gardening, then maybe it's a good thing.