Sustaining Future

Monday, December 31, 2007


In the post Every household should breed these flies, I suggested every household should breed these soldier flies. So we have buckets of soldier flies larvae. What should we do about these creatures?

The previous post From waste to food is a hint to my suggested answer: backyard aquaponics - grow your own vegetables and farm your own fish in your own backyard. See a brief history here.

The idea is quite simple. Farm your own fish. The waste from the fish is converted into plant's nutrient by nitrogen-fixing bacteria. The plants grow by absorbing these nutrient and hereby clean the water for the fish to use again.

Do it in your own backyard? Yes, there are lots of small system built by enthusiastic hobbyists which have demonstrated success. See examples. Here is a step by step guide to build one using recycled plastic barrels.

So, I think you would have guessed the answer by now. The soldier fly larvae is the food for the fish!

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From waste to food

The video linked to this title is a prefect example of good "by-product management". The unused by-product of one system is being integrated into another as input. John Todd's system produces five *valuable* by-products!

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Every household should breed these flies

By Paul Olivier on Tue Jun 24 13:30:01 2003 source

Yes, the post is several years old, but still worth your time to read:

Imagine a bioconversion process that reduces the weight and volume of food waste by over 95% within a matter of just a few hours. The process requires no energy, no electricity, no chemicals, not even water. The process is totally self-contained. It produces no effluent, and aside from a small amount of CO2, it produces no methane or other greenhouse gases. The process is housed within a container that resembles a small plastic garbage bin. The unit has no moving parts and requires no maintenance. Since it must be emptied but once a year, it eliminates altogether the collection, transport and landfilling of food waste. It can be situated out-of-doors in a shaded area, and any number of units can be coupled together to handle unlimited quantities of waste. The process generates very little odor, and at the same time, it very effectively repels houseflies and other filth-bearing flies. The unit requires very little expertise or experience to operate, it sells for less than $35 US dollars, and it can handle the daily food waste of more than 25 people. The process not only generates its own heat, but it also regulates and stabilizes heat to assure maximal bioconversion throughout the winter months.

With such efficiency and benefit, shouldn't every household breed some? It is Soldier Fly, native to America, but has already spread to the rest of the world including Australia. The conversion is done by its larvae.

[it] poses no threat to humans and has never been associated in any way with the transmission of disease. Yet at the same time, this benign creature possesses one of the most robust digestive systems within nature. It thrives in the presence of salts, alcohols, ammonia and a variety of food toxins. Upon reaching maturity, it migrates out of the unit and into a collection bucket without any human or mechanical intervention. This self-harvesting grub represents a bundle of nutrients that rivals in commercial value the finest fish meal. This creature can also be used to process poultry waste as well as human and swine feces.

more at


Sunday, December 16, 2007

The Next Oil - Burning Ice

from China and India Exploit Icy Energy Reserves

According to Spiegel Online International's article, "methane, trapped in an icy cage of water molecules, occurs in permafrost and, in even greater quantities, beneath the ocean floor. ... World reserves of the frozen gas are enormous. Geologists estimate that significantly more hydrocarbons are bound in the form of methane hydrate than in all known reserves of coal, natural gas and oil combined.

The itching question any climate-aware citizen will ask is the impact of this resource on global warming. Scientists at the Institute for Marine Research (GEOMAR) based in the northern German seaport of Kiel envision a method whereby the flammable gas would be extracted from the sediment with the help of carbon dioxide. Quoting from Spiegel Online International's article:

"The carbon dioxide could be obtained from the exhaust gases of coal power plants, for instance," says Klaus Wallmann, the direct of a research project known as SUGAR, which was recently formed to study the issue. What he proposes sounds almost too good to be true: producing fuel while sequestering greenhouse gas deep beneath the ocean floor -- eliminating energy bottlenecks while simultaneously putting the brakes on global warming.

Wallmann and his colleagues base their theories on a reaction scientists noticed more than a decade ago. When a certain amount of pressure is applied to the cage-like crystal structure, carbon dioxide can penetrate the layer of ice, at which point it displaces the methane. Then a new cage of frozen water molecules forms around the carbon dioxide. "This behavior has already been demonstrated in laboratory experiments," says Wallmann.

He is also impressed by the ratio at which the gases are exchanged. For each dissolved molecule of methane, up to five molecules of carbon dioxide disappear into the ice cage.

In addition, says Wallmann, the ice encases the CO2 in a more stable manner than it does the methane.

Is it too good to be true? We shall wait and see. At the meantime, let the scientists do their job.


Friday, December 14, 2007

Diesel Tree

The tropical trees, which have the botanic name copaifera langsdorfii, produce a biofuel that can be tapped, filtered and used to power machinery such as tractors.

It is estimated a one hectare plantation could produce 12,000 litres of fuel a year...


And at the end of the tree's life, it can be milled to produce a light brown timber favoured by cabinet makers.

"There's nothing wasted on the tree,"



Friday, December 07, 2007

Kangaroo farts and global warming

Jim Addison of Wizbang wrote in Kangaroo farts could ease global warming citing Herald Sun:
AUSTRALIAN scientists are trying to give kangaroo-style stomachs to cattle and sheep in a bid to cut the emission of greenhouse gases blamed for global warming, researchers say. Thanks to special bacteria in their stomachs, kangaroo flatulence contains no methane and scientists want to transfer that bacteria to cattle and sheep who emit large quantities of the harmful gas.

One of Jim's reader left a comment pointing out that the main conern we should focus on is CO2:
However, methane is the "greenhouse gas" which does the most damage - equivalent to roughly twenty times an equal volume of CO2.

Nice try, methane is more potent but it doesn't "do the most damage" in terms of radiative forcing (RF) because there is so much less of it.

CO2 levels are about 380 ppm and methane levels are 1.75 ppm. Even with it's much higher potency it only contributes about 28% the RF of CO2.

Furthermore CO2 has much higher atmospheric lifetime than methane. Methane's AL is about 9-15 years, while CO2's AL is thousands, if not tens of thousands, of years.

This is not to say that methane emissions should be ignored, especially regarding their contribution to positive feedback loops. However methane emissions have been decreasing since the early nineties and have even leveled off since 2000, while CO2 emissions keep increasing. Such studies as the one linked above could lead to very useful reductions in methane emissions, but they aren't going to be anywhere near enough to offset that of CO2.

I did a little research and found this:
Water vapour

Water vapour is the most important greenhouse gas, but human activity has little direct impact on the amount in the atmosphere.
Carbon dioxide (CO2)

The amount of carbon dioxide in the atmosphere is about 30% higher now than 200 years ago. The main causes of this increase are:

* the burning of fossil fuels such as oil, coal and natural gas to create energy to make electricity and to produce fuel for transport, and
* the clearing and burning of vegetation.

This gas is the biggest contributor to the enhanced greenhouse effect (about 70%)

Methane (CH4)

The amount of methane in the atmosphere is about 145% higher now than 200 years ago. The main causes of this increase are:

* digestive processes of cattle and sheep (ie their burps!)
* cultivation of rice
* escape of natural gas
* decomposing waste in garbage dumps or landfills.

This gas is the second biggest contributor to the enhanced greenhouse effect (about 20%)

Nitrous oxide (N2O)

The amount of nitrous oxide in the atmosphere is about 15% higher now than 200 years ago. The main causes of this increase are:

* burning of vegetation
* emissions from industries
* the effects of agriculture on the soil (using nitrogenous fertilisers)


These greenhouse gases have been reduced since the phasing out of chlorofluorocarbons (CFCs) to protect the ozone layer. However, other halocarbons effecting the atmosphere include perfluorocarbons (PFCs) emitted during aluminium production.

Anyway, I will give Jim the last words. "Improving feed efficiency by 10-15% would by itself be a revolutionary breakthrough, lowering food costs and helping the economy as well as the environment, even without the benefits of reduced methane."


Saturday, December 01, 2007

Start selling sunlight, Australia

[Photo credit: the Age]

Coal and oil are basically sunlight from millions of years ago. They are finite resources. Using them create green house gases. Coal mining is one of the most dangerous job... You get the idea.

Farming and agricultural produce are also product of solar energy, in the form of food.

In terms of selling essentials, there are several main categories:
  • labour (such as those sweatshops from under-developed or developing countries),
  • resources (such as all the digging happening in Australia),
  • renewable resources (such as food production as in farming),
  • service (tourism, hospitality, music, art etc which makes our life wonderful),
  • creativity (new ways of doing things, scientific research, etc),
  • Rip-off (commerce and law! :-) Sorry for the title, just a joke!)

  • Looking at the solar map above, [Yes, that's a map released by NASA showing the amount of solar energy received on earth surface. Darker the colour, the more energy received. source] Australia should start finding ways to sell its immerse amount of solar energy in ways other than farming. It is better than digging up all the earth!