Friday, September 19, 2008

We're Paying the Price Today for Decades of Relentless Dam Building


By Rachel Olivieri, AlterNet. Posted September 18, 2008.


Decades ago three new dams were started every day. But the debts of temporary prosperity are all coming due and payable today.

Between 1950 and 1970, three new dam projects were started every single day in the world. Today, primarily in China, Turkey, Brazil, Japan and India, one new dam project begins daily with an average completion date of four years. Fifteen hundred dams are currently under construction worldwide.

Dams fragment, divert and subjugate the world's rivers. In one long lifespan, beginning with the inauguration of Hoover Dam in 1936, the engineering marvel of the 20th century, civilization has altered the most important function that makes the earth work, water. Thus, transmuting humanity into something foreign to the earth it inhabits -- a stranger to the very system which gave rise to our species.

The late Carl Sagan was among precious few visionary humans who shared the extraordinary ability to differentiate between deep thought and deep nonsense and recognized the persistence of a satisfying delusion to perpetuate the latter. Dr. Sagan wrote, "We go about our daily lives understanding almost nothing of the world. We give little thought to the machinery that generates the sunlight that makes life possible, to the gravity that glues us to an earth that otherwise sends us spinning off into space or to the atoms of which we are made and on whose stability we fundamentally depend."

Without some sense, some outline of how the earth works and our relationship to it, one is deprived of knowing, let alone of asking, the really important questions that promote regenerative life and prevent massive-scale destruction and degeneration.

It is only in blindness that ignorance can find engineering arrogance and feed the certainty of human expediency -- that millions of dams can exist worldwide strangling the lubricant of life itself. It is true that dams have created a seemingly unlimited oasis in arid and semi-arid regions of the world and have produced unimaginable population centers in water-stressed locations, made possible food production on marginal arid lands, and provided cheap taxpayer subsidized water and artificial lakes aplenty for fishing, camping and boating.

It seems a good thing, yet, what isn't accounted for is the short-term duration and ecological costs. It has created this artificial bonanza by short-circuiting the natural system of limitations much as the one time wonder of fossil fuels has short-circuited and driven the industrial revolution. The debts of temporary prosperity are all due and payable in the 21st century.

In the present state of affairs, water, energy, population, war, global economic expansionism, and failing ecological systems are sending shockwaves throughout the vulnerable global community while staggering the biosphere which keeps us among the living tentatively.

Earth Recycling

The world's water budget is a fixed volume and has remained unchanged for roughly 2.2 billion years in its present state. About 1 percent of the world's total water circulates as freshwater while oceans represent 97 percent of the world's stores and the remaining 2 percent is tied up in glaciers and polar ice caps. This finite water pie divides ever more thinly as population, agriculture and the industrial economy expands.

The uninterrupted Earth is a dynamic solar and geothermal energy system which powers the hydrologic and rock cycles. It conducts and convects energy flows from the earth's 10,000 degree iron core outward through the mantle and lithosphere (crust) generating plate collisions that move continents and trip earthquakes. Magma driven plate collisions uplift mountain ranges and setoff volcanoes recycling lava and gases on land and underwater replenishing both with life-producing minerals.

Solar energy evaporates surface water primarily from oceans to atmosphere to land as water or snow. Erosive rainfall or expanding ice in rock crevices tears down mountains as fast as they rise. The Earth's lumpy land surface is a massive drainage system. From high to low, meandering and networked creeks and rivers drive the rock and mineral cycle. A river system operates on the principle of erosion and deposition. As a river gains water volume and speeds up it erodes and picks up rock and sediment. As it loses volume and slows down it drops some of its load. Large pulses of water flush sediments onto the rivers floodplain creating fertile soil before arriving at its delta entry to the sea.

Remaining sediments combine with the heavy basalt sea floor at the shoreline which is being subducted under the lighter continental plate from volcanic spreading forces at the Mid-Oceanic Ridge. This continuous underwater volcanic ridge runs like the seams of a baseball throughout the world's oceans. Everything cycles like a big conveyor; from Mid-Oceanic Ridge pushing the sea floor towards continental plates where it subducts back into the mantle to raise a mountain or explode through a volcano over geologic time. Dams, known as nickpoints, interrupt and distort the natural transport machinery between land and sea.


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