you could take the cradle-to-cradle approach and make the whole landscape out of plastic which can be repurposed indefinitely.

'course that would take energy....

hehe he!

Of course you could also bake everything into charcoal and then crush it into a giant diamond- very, very long lasting carbon...



but seriously- any 'scapers out there?

Carbon sequestering does seem like the latest trend. High carbon content building materials like mesquite or bamboo offer some potential. I believe there are also newly formulated concrete compounds that draw negative gases out of the air?

In our Solar Decathlon entry at A&M we're looking to carbon balance our building via the landscape and I know a slew of landscape students are making some sort of sculpture garden out of eco-cement which is carbon dioxide absorbing.

Jbond-

I know of several 'smog eating' materials that break down NOx and hydrocarbons via catalytic reactions, but I've not encountered the claim that CO2 can be absorbed in any meaningful amount by a non-living system without active chemistry/mechanisms. There are also several 'self-cleaning' surfaces/coatings available that keep building clean.

Does the carbon sequestering 'crete absorb more carbon then is released when the cement is created by roasting limestone?

The highest amount of recycled flyash/slag/pozzalans that i've seen referenced is about 40%... so that leaves lots of carbon being created by processing the cement.

thanks for pulling this thread back from oblivion;)

JBond...your giving away your teams secrets

-SD2007 Spy-

We don't have secrets at A&M. We actually had our construction docs on a public website for a while before our energy people flipped out and we took them down.

Anyway...

You're right about process emissions with any co2 absorbing cement. The manufacture is still a large source of emissions but as this site notes, if the energy used is from power producers with low or zero emissions then it's possible to achieve a carbon neutral or carbon positive product.

These guys make the aforementioned eco-cement. Their site is atrocious... but they mean well: TecEco

Ultimately though, the biophilic and carbon sequestering implications of actual vegetation are far more interesting to talk about than how "fix" concrete. I'm very interested in the intensive reintroduction of diverse ecosystems back into urban life- anything from intensive urban agriculture to aquaculture, permaculture, [insert]culture...

It's fun to think about the quantities of vegetation that we actually need to offset our current carbon emissions. The aesthetic implications on cities alone are worth dreaming about.

Ken Yeang's work starts to speak to this though I personally don't care for his aesthetic.

oh jesus, finally!!! I'd found the TecEco website back when I was in my thesis semester, and then could never find it again. I've been telling people that I'd seen carbon-eating cement somewhere, and they laugh at me. Now I feel comforted that even if I've been fooled by a gimmick, at least I'm not the only one.

Can windfarms be sustainable? I think so, particularly since you can plant stuff between the windmills. But remember to check whether you're in an important bird migration path before you select a site.... or else bye-bye, birdies!

A like the idea of a diversity in power production based on geography and climate.

solar in the desert, wind on the coast, tida power in fundy, hydro in the fjords etc. etc.

If our power production was less concentrated and more locally produced (which would reduce line loss) this diversity I speak of would introduce a whole new form of technologically influenced regionalism to the built environment.

Windfarms and solar arrays are interesting to me because, as far as clean energy goes, they have powerful aesthetic identities which could begin to evolve people's a priori images of places. ex. When you think west Kansas you see endless fields but maybe no they're punctuated by windmills- (which could be an elegant tie between earth and sky imho :P).

Unfortunately those two solutions aren't overly effective everywhere. A biofuel power plant doesn't have the same region defining effect as wind or solar but who knows- maybe if regions relying heavily on biofuels began to incorporate plantings used to produce the fuel along highways or other neglected landscape areas they could affect places that way.

I keep mentioning this "regional" thing only because I'm a little dissatisfied with the ubiquitous 'any-town USA' appearance of our great country's landscape and would love to see technology and neccesity lead the way toward a urban landscape that is varied, vibrant, well adapted and with a heightened sense of place.

am sure you already know about jack and nancy todd and ocean arks international, but just in case...

i have proposed installing living machines in projects at school and the office since the late 80's, and always meet with blank stares from profs and colleagues, but still think they are quite interesting.

living machine is not exactly about carbon neutrality, and not certain if the system works towards that goal or not, but it could be an interesting way to get things started if looking for a different approach...either way, more than greenhouse gas emissions i think one of the more immediate issues we are going to face if the world really does heat up is severe lack of potable water, and they offer a non-high tech (mechanical) way of dealing with the problem...

more to your question...i did a fish farm research project last year that was based on methods of carbon sequestration and kept hitting the brick wall of the release of previously absorbed gases as organic materials rot. we proposed using plant matter as biofuel source so energy use cycle could at least move towards carbon neutrality, but numbers really never added up, and we ended up proving more or less that carbon neutrality in landscapes (or production landscapes anyway) is intrinsically tied to the energy system that sustains them. That is, we all realised we were at the wrong end of the stick. our prof agreed, even though his research as an ocean scientist is based on the opposite approach...

I'm not yet sold on TecEco- they are too vague on what the materials are and where they come from. still, it is an seductive idea.

Living machines rock, but I've heard lots of anecdotal issues with their maintenance and getting them to initially work. Engineered wetlands seem to be more robust and practical ecologically/economically in most situations that I've studied. the floating island 'restorers' are very cool - love to see more of them installed.

there is a possible confluence between ocean ark's mission and the vertical farm movement- is this the new paradigm for eco-cities?

Has anybody collaborated with Ocean Ark or hired them to consult on a project? Curious to know how collaborative versus proprietary they are.

Water is probably the most significant impact of climate change, some places will have less and some more, some places will flood, and others will melt. Water is directly tied into our energy consumption, from heating water for our showers, to running the pumps that deliver water to our taps. (this is not insignificant - california dedicated the entire output of a nuclear plant to pumping water over several mountain ranges along the path of the california aquaduct.)

So how many acres of wetlands would be required to treat all of Los Angeles waste water? if 1 square foot of wetland can treat 1 gallon/day (a rough figure derived from studying lots of municipal scaled treatment wetlands). taking Hyperion Treatment Plant (one of the largest in the world), with 'The plant has a dry weather capacity of 450 MGD for full secondary treatment and an 850 MGD wet weather capacity. Current flow is 340 MGD.
so 340,000,000 square feet = 7,800 acres or 12 square miles - wow!!! Ok that area could easily fit 16,000 houses. But out of the entire city of LA's 465 sq. miles that is not that much. If you factor in the ecological benefits of that much wetland restoration (pre-anglo LA had easily 10x that amount of wetlands), it starts to make economic sense. And if you start to recycle that water instead of discarging the effluent into santa monica bay- that is about ten times the amount of water imported into southern CA 191 billion gallons each year. So what would LA do with all that water? What would the Owens Valley, Mexico, the Sacramento River, and all those other places do with that additional water?

ok, back to our regularly scheduled program...

I calculated 340,000,000 square feet at 258 square miles.

340,000,000/5120 ft/mile = 66406 square miles

square root = roughly 258 square miles... which is a much larger chunk of LA

Further, one of the issues with wetlands is the aquatic plants within them must be meticulously maintained. The purification process relies on the effluent passing through the root systems of the plants. As the plants grow and their roots thicken their ability to purify the water becomes compromised as they impede the flow. So then these plants must be replaced.

I pity the fool who does maintenance on 258 square miles of wetland. Further, there would need to be a carefully monitored ecosystem much like in natural pools where insects who prey on mosquitoes would be cultivated in order to prevent an enormous breeding ground for west nile virus.

I agree with you that just to begin- the amount of water we'd save by cycling gray water, or water collected by rain catchments for use in flushing toilets or for irrigation is astounding.

Back on the intensive agriculture tangent: I've seen succesful systems that use a tank full of Tilapia fish to provide nitrates to an aquaponic vegetable garden. You feed the fish, their waste feeds the spinach plant. The quantities of protein and vegetables produced in these systems are fantastic and I can dig up literature if someone is interested. The main problem with them: who wants to eat that much tilapia all the time?

Though I sorta shat on the idea of waste water wetlands as a sole solution to the water crisis- it still is a valid idea that is worth exploring. The wetlands provide ecosystem, they sequester carbon, and they have utility in treating water. If we can get better at understanding how to balance these ecosystems (because we are a neglectful, busy people in America) then I could see them incorporated in small applications all over the country- the aggregate effect being pretty tremendous. Natural swimming pools are also interesting- same principal, rather than chlorine you're using a compartmentalized wetland system to purify ye old swimming hole.

Jbond -
I stand by my math. I used 'calculator' by Apple for the conversions of 340m gal=sf still equals 12 square miles :-P

when you compare the maintenance for 12 square miles of ecological wetlands to a $2b engineered machine aka treatment plant that only does one thing and produces 3 products (treated effluent dumped miles out in the bay, treated sludge aka biosolids, and methane) versus a biologically diverse wetland that can produce talapia, biomass, clean air, clean water, scenic views, recreational space, educational space, and many more positives...

nice pic! A more practical solution is distributed treatment/water recycling- I should go work for Equaris because I see the potential for on site water treatment and composting...

You're right, I didn't divide by an extra 5120ft- which results in 12.9 square miles.

To put 12.9 sq. miles of wetlands in context, LADWP has spent about $500mil on dust control and created about 40 square miles of mudflats on Owens Lake 'bubblers'. Ok, this is not an ecologically diverse treatment wetlands, but the conditions there are much more severe and harsh then what typically is experienced. But this isn't a sustainable landscape, but a place that will need ongoing intensive maintenance in perpetuity till LA stops diverting water from the owens river.

hmm tk I'm wondering about this statement at first thinking that it was an oxymoron, that landscapes are generally lower on the carbon footprint that say buildings. But taking contemporary examples I was seeing that much of what is used required alot of, for loss of a better word, processing. The mulch chips had to be cut from the bark of trees which is unlikely a manual task, to the hard surfaces.

I suspect that one could make a case for the use of zero energy materials, as well low maintenance garden-scapes...possibly self watering

aren't deserts the true zero carbon landscapes?

so is antartica and iceland...

What about some type of intgrated system? Are environmental based systems alone are enough to cope with human urban requirements? I don't think they can handle the entire load we would need to put on them. Is there any precident for an integrated wastewater treatment system?