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Construction and the Built Environment
Various mega projects leave more than just a huge carbon footprint on the earth.
How construction and the built environment can both benefit and harm the natural environment
Building projects great and small have their impact on the environment. Yesterday's solutions become today's problems, which we must then apply ourselves to solve. The built up world that we have made for ourselves is filled with examples of just what this means. But not all building and construction is detrimental. As we learn about the environment, we can use what we build to enhance the environment; but this is something of a two edged sword. There is nothing that we do that has a double influence; both positive and negative.
Agriculture has shaped entire landscapes, eradicating forests and sculpting mountains. Monoculure cash crops results in crash economies. Biodiversity disappears and with it comes a new ecosystem seeking some kind of balance. But even here we intervene to keep mono cash crops intact. Agriculture has gone a long way to feed humanity, but this is something of a tradeoff. The fact remains that despite our ability to reshape the land to grow more crops, many people still go hungry. Then there are the cultivated parks, greenhouses and gardens that attract attention around the world because of their beauty. These regions tend to be well kept and healthy. They are an excellent learning facility on biodiversity.
Mega projects like the Three Gorges Dam, Aswan High Dam, the Suez Canal, The Panama Canal and Hoover Dam all have had major impacts on the environment. Shipping locks on the St. Lawrence has allowed foreign species like the lamprey eel to invade the Great Lakes and destroy resident eco-systems. The Three Gorges Dam on the Yangtze River in China has forced millions of peasants out of their homes as Chinese power magnates seek their fortune in electrical power. The displaced people have no were to go but in mega slums, extensive pollution and dire poverty. Anyone protesting this is removed and "re-educated." Many are never seen again. The Aswan High Dam was built on the Nile River for similar reasons, but it stopped the inundation of the lower Nile regions. The silt got trapped behind the dam instead of being delivered to the delta. The silt has to be dredged and the delta is slowly disappearing as is the nutrient rich soil in the lower Nile region. The Suez Canal allowed the cross transfer of species between the Red Sea and the Mediterranean, though it shortened shipping routes away from the dangerous seas at the horn of Africa. The Panama Canal has a similar effect between the Pacific and Atlantic Oceans. The Hoover Dam has backed up so much water, it has been known to trigger earthquakes in areas that were flooded. In addition, it cut off natural fish runs. Many rivers on the west coast has suffered the same fate resulting in the loss of the salmon run.
Super highways and pipelines extending for thousands of miles have had a huge impact. Wild caribou have had difficulty in migration due to the presence of pipelines blocking their path. Highways impact with increased road kill, but these same highways permitted rapid delivery of everything. Even though passage ways have been added recently and new designs incorporated into pipeline construction, there are still problems as these have to be found in order for migrating spaces to use.
Open pit mines, coal collieries, uranium mining, iron and nickle mining have had devastating results. Open pit mines can be huge, some being seen from space at a few miles wide and more than a mile deep. All that excavation must be put somewhere as we continue to chase the mineral seam ever deeper into the Earth. The tailings get distributed in the surrounding landscape with detrimental results to local streams, flora and fauna. The typical coal colliery is a wasteland of slag, coal and coal dust. Miners' health is also ruined so that coal fired industry can run unabated. As we learn about carbon, coal is now being attacked, but its use is still on the increase for coal fired power plants and especially in China. Uranium mining and processing is in a league of its own with the end result of nuclear weapons and the threat of nuclear holocaust and the reality of nuclear accidents. Iron and nickle mining and processing has turned some areas into lunar like wastelands. The lunar astronauts of the 70's practised in the wastelands surrounding Sudbury Ontario. But the iron and nickle age has given us railways, shipping, air planes bridges and housing. Raw resources allow us to do many things that were once though to be impossible.
China's new megaproject
Oil processing and refining has given us the fuel to run transportation and industry as well as materials to cloth us and build. At the same time, use of oil and oil derivatives have contributed significantly to global warming and pollution. As we are aware of this, alternative energy sources are being sought such as hydrogen power, geothermal power, solar power and wind energy.
Fish farming, though promising a constant flow of fresh fish have hit wild stocks hard, threatening to drive some to extinction. The problem stems from parasites that breed on fish farmed stock that then transfer to the wild fish with devastating results. Many people agree that wild fish are tastier and better looking than the farmed counterpart. Fish farming has the advantage that selected fish can be grown and harvested without detriment to other species. The fish are grown in net pens and are far easier to catch without destroying wild environments. However, the parasite problem may do that indirectly.
Factory farms are an exercise in efficient food production, but are arenas of cruelty. Just as in mono cash cropping, a large warehouse is used to house a single kind of animal for the market. It can be pigs, turkeys, chickens, ducks, geese, beef and other animals. They are concentrated without much opportunity to move. As disease is a threat to overcrowded conditions, these animals are raised with antibiotics which then get translated up the food chain to ourselves. Many are fed growth hormones as well which also get passed on to us. There are groups who protest the cruelty of the growing conditions and overcrowding and this is effecting some change.
Megacities concentrate pollution from industrial processes, car and truck engines and air planes, which then spreads around the world. Pollution in these regions occurs because insufficient attention is paid to controlling wastes from entering the land, water and air. The Olympics in Beijing in Aug. 2008, proved that a huge city can be cleaned almost entirely of pollution if the desire is there. Formerly, Beijing was one of the worst polluted megacities on the planet.
There exists means to remove carbon from the atmosphere and fix it chemically so that it does not pose a hazard in global warming and the consequences thereof. The process involves extracting carbon dioxide by freezing it out and subjecting it to a chemical process with calcium hydroxide to make calcium carbonate. The first step would be to collect carbon dioxide by condensing it out of the atmosphere by running atmospheric gasses through a freeze condenser that would make dry ice, or frozen carbon dioxide. This is done routinely, so it is not a problem. Next the dry ice is placed in a solution of calcium hydroxide to make the calcium carbonate.
Industry manufactures calcium carbonate by passing carbon dioxide through a solution of calcium hydroxide. The calcium carbonate precipitates out of the solution. The chemical formula is;
Ca(OH)2 + CO2 ---> CaCO3
This is where we can begin to extract large amounts of carbon from the atmosphere and stabilize it, relatively speaking. As long as the calcium carbonate is not exposed to something like acid rain, it remains stable. It can be used as a building material and nature already does so in the form of clam-shells and bones. We already use lots of natural calcium carbonate in construction and can augment this using artificially made calcium carbonate. This is probably by far the best solution. We can develop the technology to begin extracting the carbon out of the atmosphere on an industrial scale, but it is going to cost. For the moment, it seems that the governments of the world would have to get behind this one as industry, especially the fossil fuel sector, is slow to pursue this research and development. It should come out of taxes and massive projects should be designed and built to begin the process of removing carbon and stabilizing it.
The built environment has both positive and negative qualities that can benefit and harm the environment. It is up to humanity to chose the beneficial and positive over the merely profitable.