Geomimicry[1]

The term geomimicry is used by John Harrison to describe processes and technologies that mimic long term geological processes.

During earth's geological history, large tonnages of carbon were put away as limestone and coal by the activity of plants and animals. Shellfish build shells from it and trees turned it into wood. These same plants and animals wasted nothing, the waste from one was the food or home for another.

The solution to problems of carbon dioxide greenhouse gas and waste is to mimic nature and use them both to make building materials. Because of the size of the potential reverse flows the built environment is the ideal place to start. Such a paradigm shift in resource usage will not occur because it is the right thing to do. It can only happen if people can make money making it happen.

To succeed this process of reversal must be profitable. TecEco and other Global Engineering Alliance members have developed new technical paradigms that working together in a tececology can resolve the problem of excess CO2, waste and water shortages. By using carbon dioxide and other wastes as a building materials we can economically reduce their concentration in the global commons.

Geological Processes Past and Present

Geological processes of deposition have been sequestering carbon since the Achaean and the recent (holocene) period shows a strong correlation between the concentration of CO2 in the air, global temperature and sea level.

The Correlation between Temperature and Carbon Dioxide Concentration in the Vostock Ice Cores[2].

Climate changes over geological time due to the influence of many factors however one of the most important is the composition of the atmosphere. Since the Achaean there has been a feedback system between carbon dioxide consumers and oxygen producers resulting in an atmospheric and climate equilibrium. There is no doubt that we are rapidly changing atmospheric composition increasing the CO2 content and reducing the oxygen content thus altering this equilibrium. Are we now the most relevant factor and “Weathermakers”[3] If so we will have to take on the role of planetary engineers[4] The present rate of change suggests this may be so. Can we learn from the past to modify our impact ? Can we mimic geological sequestration in the past but at a much more rapid rate? Geological history provides some dire warnings about precedents for Greenhouse Gas driven warming. Gaia theory describes a model in which life and the planet interact to control climate and which greenhouse gases are reduced by photosynthesis but increased by respiration, volcanic activity etc. and during the glacial/interglacial cycles, CO2 concentrations and temperatures show a remarkable correlation. There are documented events in geological history where global warming has been caused by atmospheric change. Correlation Between Temperature and Rainfall over Geological Time[5]

More and more the evidence is mounting (Pollen studies, ice core studies, foraminifera, isotope studies etc.) for previous rapid climate change correlated with CO2 change even during the relatively stable quaternary period.

Correlation between Temperature and CO2 over Geological Time [6]

From the geological record we know that most carbon came from the outgassing of volcanoes and lavas and was initially in the atmosphere in the form of CO2. We also knwo that the fossil fuels now used by us have been created as a result of the decomposition and putrefaction of forests that during several periods and in particular the carboniferous covered the earth and removed a large part of CO2 from the atmosphere.

Consider just the tail of the above graph in more detail

Global palaeoclimatic temperature behaviour from 180 million years before the present up to now, in 3 different time scales. The Vostok ice core data cover roughly the last half (4440,000 years) of the 1 million year interval marked with the arrows[7].

The equilibrium temperature of the atmosphere depends on the concentration of several greenhouse gases (GHG) which control the natural greenhouse effect as a result of which the present average temperature on the planet is about +15 deg. C instead of about -20 deg. C (below zero). CO2 is not the most powerful, but is the most abundant of these greenhouse gases.

Some 150 million years ago the surface of the earth was covered with forests and the average temperature was about 10 deg.C warmer than now, the sea level was very likely about 70-90 meters higher than now, and there were practically no ice caps in the polar regions. it took some 100-180 million years, for photosynthesis to remove a large portion of the carbon from the atmosphere, storing it into plant tissue. Uptake of CO2 in the oceans took a similar time.

Since the industrial revolution we have been putting back that carbon into the atmosphere, burning fossil fuels in order to get energy and in only 100-150 years the amount of carbon dioxide has increased significantly at a rate which is a million times faster that the natural inverse process described above, which stored the carbon and the energy associated with it in the first place. The climate equilibrium states are thus perturbed at an umprecedented rate, implying a possibly "runaway" and/or devastating enhanced greenhouse effect.

We are rapidly changing the atmosphere and this will most likely trigger massive climatic change? Consider just two events from the past

The Deccan Traps Eruptions and the Extinction of the Dinosaurs

The Deccan Traps formed between 60 and 68 million years ago at the very end of the Cretaceous period. The bulk of the volcanic eruption occurred at the Western Ghats (near Mumbai, India) some 66 million years ago and may have lasted less than 30,000 years in total. These massive and sustained volcanic episodes in India altered the atmospheric chemistry of the period and caused a drastic climate change which may have played a role in the extinction of the dinosaurs.

The Paleocene Eocene Thermal Maximum

Roughly 55 million years ago during the very early Tertiary epoch, ocean pH levels dropped drastically and global temperatures rapidly rose 5 deg.C. The resolution of proxy records that are available indicate that this happened in a period of time no longer than 5K years. (It is not possible to know if it happened even faster)

The likely cause of this event was massive feedback systems such as releases of methane from the ocean floors as methane clathrates melted or releases of methane from the arctic tundra triggered by a smaller warming or changes in sea level.

It took over 100 thousand years for the ocean, atmosphere and temperatures to return to their previous state. The result was a mass extinction event that took millions of years to recover from.

The Carbon Cycle, Plate Tectonics and the Long Term

There is a long term interplay between tectonics and hydrology. When sea floor spreading rates are high, carbonate rock (the biggest reservoir of carbon) on the sea floor is taken down with sinking plates and thermally decomposed releasing CO2 into the atmosphere (through volcanoes, thermal geysers etc.) producing more greenhouse-induced warming.

As a result of the greater emissions during periods of more rapid plate movement , more evaporation and rainfall generally occurs and the rate rocks are weathered increases mainly due to increased concentrations of carbonic acid (H2CO3).

The increased weathering uses up CO2 and tends to reverse the greenhouse warming. The reactions are exemplified by the Urey Reaction:

CaSiO3 + CO2 = SiO2 + CaCO3

As an example, wollastinite reacts with CO2 (actually carbonic acid) to make quartz and calcite. Increased atmospheric CO2 drives the reaction to the right and thermal decomposition of calcite drives it to the left. Other silicates also can be used to show this process and are being considered by some for mineral sequestration..

Unlike the situation on Venus, which has a 90 bar CO2 atmosphere with a runaway greenhouse that produces a surface temperature of 740 K, the earth seems to be buffered from extreme greenhouse warming. It is thought that Venus is too close to the sun to have allowed oceans to form. Thus CO2 had no where to go and the planet has been enshrouded by a dense CO2 atmosphere for all of geologic time. Mars may once have had a CO2 induced greenhouse, but slowing down of tectonic activity and continued production of carbonates would have cooled the surface and placed the planet into the "deep freeze".

On Earth there also seem to be regional-scale interplays between climate and tectonics. The uplift of the Himalayan Plateau began approximately 30 million years ago. This is about the time that isotopic signatures in deep sea sediments suggest that the Earth began an extended period of cooling. What seems to have happened is that uplift of the Plateau enhanced the Indian Ocean summer monsoons, creating massive amounts of rainfall and associated weathering leading to the consumption of CO2 from the atmosphere and accumulation as sediment on the sea floor.

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