Eden Climatics

My post yesterday explains how we might implant garden like conditions everywhere. Of course, I look to resolving the worst conditions like the center of the Sahara and also recognize that it will be process of advancing the living edges toward those centers. We mean though that in time it we can plausibly replace all deserts everywhere with a woodland climate holding ample humidity. Dry grasslands are obviously included as are mountain slopes and hillsides.

It will take a long time and a huge number of human work years to achieve once we decide to do this.

Yet anyone who looks at the globe knows that the present well watered ecosystems are a small fraction of the globe’s land area. The Sahara leaps out, but so too does Western North America and most of Asia. Well watered is not how you would describe most of the Globe. Yet our objective is to make all of it well watered.

This will have a major impact on global climate and most pronounced in the Northern Hemisphere. Most importantly, all this woodland will be absorbing energy into its biology. This is sunlight that has previously been reflected back out into space and lost or at best used to warm the atmosphere.

Thus we can expect the climate zones to migrate north and a huge moderating effect to be observed. I would expect a full spring breakup and flushing to develop in the Arctic of all sea ice every year. We are close to those conditions now and a flushing of excess heat would do it quite nicely. We saw it in action in 2007.

Such a transformation would certainly moderate the northern climate and create European weather to the higher latitudes in North America and Russia where we are already used to dealing with shortened growing seasons.

We already have surmised that a covered Sahara during the Bronze Age gave us the climate optimum of the time that lasted just to the end of the Bronze Age. That acts as a good check on our expectations but also tells us the correct direction of change.

In practice woodlands and general growing environments that are not arid bring their own natural microclimate. Properly managed, these can cover most of the globe.

Geological Climate View

This is a geological viewpoint of man’s impact on the climate and it is naturally very conservative.

The one event not recognized is the unusual temperature collapse coinciding with the end of the Bronze Age that has never been reversed. My conjecture is that this was caused directly by the deforesting of the whole Sahara resulting in the reflectance of incoming solar energy back out into space. This represents a huge chunk out of the global energy budget.

That is a man made climatic change event that puts current activities in the shade. We can and will reverse that event and in the process provide home and agriculture for billions of people.

Otherwise, the claims of significant human impact in the modern era are hard to substantiate or quantify and appear to be a distraction from real efforts aimed at the terraforming the earth.

As I have stated, it is becoming possible to convert all the deserts into productive farmland and woodland. It is also massively beneficial to do so.

Man's contribution to climate change is negligible in geologic time

http://www.examiner.com/x-2950-Denver-Energy-Industry-Examiner~y2009m3d21-Mans-contribution-to-climate-change-is-negligible-in-geologic-time

March 21, 11:49 AM

Most geologists, including those in the energy business, take a REALLY long view of the earth's history including global warming and cooling cycles. Within the framework of geologic time, i.e. the earth's history, man is a very late entry and relatively small contributor to climate changes.

The current debate concerning global warming is well publicized. It features histrionic presentations of data on both sides of the issue usually by writers or politicians, with no scientific background, "interpreting" volumes of data gathered by true scientists. The arguments, for and against, have been going on for about 40 years. The earth is about 4.6 billion (4,600,000,000) years old so the debate has been going on for about 0.000001% of geologic time. Man, or at least our earliest demonstrable "human" ancestors, arrived about 2.3 million (2,300,000) years ago so "man" has been an observer of climate change for about 0.05% of geologic time.

Climate change, as measured and recorded in the fossil and rock record, as "ice ages" (global cooling) and ocean expansion (global warming) have been occurring periodically but erratically throughout geologic time from about 3.3 billion (3,300,000000) years ago or approximately 1 billion years after the earth formed. The earth basically "cooled" from its nuclear, "Big Bang", inception for over 1 billion years. At least two, multi-million year length "ice ages" occurred before the first signs of organic, carbon based life in the form of algae or pond scum. At least four more ice ages occurred from the age of pond scum, through the age of creepy crawlers, fishes, amphibians, reptiles (dinosaurs) and early mammals. In the last 1 million (1,000,000) years, during the age of man, at least 10 well documented periods of cooling have occurred. The last "ice age", lasted about 60,000 years from approximately 70,000 years ago until about 10,000 years ago. In North America, the timing and duration are determined by measuring the advance and retreat of glaciers in the fossil plant and rock records. Within these overall "ice ages", there are also shorter cycles of warming and cooling. The warmer periods, in today's vernacular, would be called "global warming."

Without question, man's use of fire (wood), dating from 1.5 million years ago; coal, from about 3000 years ago; and petroleum for the last 150 years have contributed to the most recent cycle of warming. The significance of man's activity is a part of the ongoing debate. The CO2 emissions and ozone layer changes are measurable phenomena. The so called "greenhouse effect" is an unproven theory. At worst, however, man's contribution looks to have only "sped up" the earth's natural cycles by a few decades. Obviously, a "few decades" are significant to the earth's current human population but not in terms of impacting the earth's climate history. If this speeding up process began with the first burning of petroleum 150 years ago, man's activities have affected 0.000003% of the earth's history; 0.0065% of man's history; and 1.5% of the time since the end of the last ice age.

Some evidence exists suggesting that the current phase of warming MAY have peaked in the 1970s and the earth MAY be returning to a cooling phase. Regardless of the rhetoric on either side of the arguments, man's total contribution to global climate change is negligible and probably not measurable within the context of geologic time. Instantaneous events like the asteroid or meteor strike that ended the age of dinosaurs by creating a global wide "dust cloud" or continuous volcanic eruptions that have also shrouded the earth with ash and smoke clouds have had a far greater and long lasting effect on climates. If all of man's "contribution" were to cease immediately, the net effect, measured in geologic time, on the earth's natural warming and cooling cycles would not be measurable.

www.talkorigins.org/faqs/faq-age-of-earth.html
www.studyworld.com/newsite/ReportEssay/science/Earth%5CThe-Ice-Age-36240.html
http://icecap.us/index.php/go/joes-blog/global_cooling_is_here_evidence_for_predicting_global_cooling_for_the_next_
http://library.thinkquest.org/26157/fire_use.html
http://ecology.com/features/originsoflife/

The Eden Machine

The Eden Machine

Some friends of mine who control the public company known as Lifespan LSPN:PK lifespaninc.com) have decided that it is a great time to pursue the development of my atmospheric water harvester concept and are prepared to organize the necessary funding to make it all happen. I formulated the original concept four years ago as part of writing my manuscript Paradigms Shift and then excerpted the key chapter as my third post when I initiated this Blog. You may want to read that particular post at:

http://globalwarming-arclein.blogspot.com/2007/02/global-terraforming-chapter.html

I have referred to the concept many times since. The problem can and has been solved expensively using classic technologies primarily as a drinking water system using household power. It is after all a variation on a refrigerator used to collect humidity.

We have to go far beyond this, but we will give ourselves one break. We do not need to fuss with the water itself because it will go directly into the adjacent soils for irrigation purposes. There are three primary subsystems besides the control system. We have already recognized the need for refrigeration. We also need energy storage but it does not need to be mobile which will let us work up prototypes with our old friends the lead acid battery. Then we need an energy source other than the power grid.

The first big saving comes from the mere fact that the power used will not travel removing the whole issue of transmission losses. With the water also not traveling we are designing a stand alone unit that can be placed anywhere, set up and walked away from potentially for months at a time, except for occasional maintenance.

We have already decided that the optimum design objective is a device capable of collecting 100 liters a day at close to 100 percent humidity. We formulated this around the knowledge that a full grown fruit tree will respire 50 to 70 liters of water per day. This makes it easy for operators to manage their units.

We am expecting to use a solar array to generate the working energy and was in fact waiting for the cost of solar energy to come down to around $1.00 per watt. This year, Nanosolar announced just that price and are now shipping. However, for prototyping, any supplier will do initially. We will simply design so that various panels can be switched in and out as needed.

The solar panel could be put on a mast as the trees grow larger, but in the early stages a simple upright sheet should be sufficient and save on excessive hardware. In some respects, this part of the system can be expected to follow the development of the original satellite antenna that went from six feet across down to eighteen inches and design can easily accommodate that sort of shift. Having them initially close to the ground also allows easy cleaning protocols and maintenance.

We also recognize that we need to store the solar energy during the day and consume it at night after the temperature has broken for maximum yield. The most likely battery system will be the vanadium redox battery. It weakness is low energy density, but this is offset by the capacity to cycle millions of time without ever wearing out the battery, The energy is also stored by pumping the active fluids into tanks after been acted on. There is also no particular limit to the speed of the process. The energy can be collected and stored for twelve hours and then dispensed in two hours, which may be the optimal design. The fluid tank can act as an anchor to the static system as well. The cost of the membranes is still custom driven, because no mass market has been yet developed for them. We may be the necessary mass market.

The good news is that the Vanadium Pentoxide is a one time purchase that will be recoverable. We do not know yet how many pounds will be needed and I would be guessing if I suggested a hundred pounds.

The stored energy is then released at night to operate a solid state cooling system which passes already night cooled air over it to induce the separation of the humidity. The dried air is then passed over the hot obverse side of the same panel to carry off the heat produced by the panel. The Eden machine is designed to cheaply, efficiently and continuously generate water for human, agricultural or industrial utilization.

We know where we wish to end up and I know that it is possible to produce an expensive working machine. We are in the same position that Henry Ford had at the dawn of the automobile age. A wide array of design elements will be pursued with the objective of driving the manufacturing costs down in incremental steps to achieve our goal.

We expect that our first customers will be back yards in LA and later, the Great Valley. After that we are good to go. It would also be fun to manage a million acres in the Empty Zone. Note that efficient application of the technology will commence in high humidity areas and progress toward more arid zones bringing their water with them in the same manner that the Amazon is watered. Once proper tree cover is established with absorptive soils, we can expect natural precipitation to largely take over most of the work load.

We also plan to be Nanosolar’s best customer before we are finished. I only wish that I could buy stock in that company. Anyone that can attract 300 million in private investment to build a couple of factories has my attention, to say nothing of their two million dollar tool that produces the power equivalent of one nuclear plant per year.

After the Bronze Age

The one major climate anomaly that needs explanation is the Bronze Age warm period and its aftermath which we are living in today. During the Bronze Age, the climate appeared to be, at least on the basis of the science to date, a couple of degrees warmer than the present temperature regime. It ended with a bang as Hekla blew up, but why was recovery never full? We have had near attempts to restore that climatic regime, such as the medieval warm period, but all have ended badly. We are now clearly living through another such warm spell.

The chart shows a two thousand year warm spell that was untouchable. I have to accept that the data proxies are also fairly consistent for that era. The question remains, what mechanism lowered the global heat content?

For that we have the stripping of the Sahara by misplaced human agricultural practice. Today, solar energy is not absorbed or stored there at all. It is mostly reflected back into space. If that energy were been collected by vegetation, it would represent a huge addition to the earth’s heat content. The loss of that heat surely was responsible for post Bronze Age coolness.

We now have increasing evidence that the surplus CO2 in the atmosphere has now encouraged an increase in plant life throughout the globe. This should increase direct solar energy absorption and has likely contributed to the slightly warmer global conditions. Note the attached report.

With this excess of CO2 in the atmosphere, there is ample reason to restore the Sahara as growing environment. We have already addressed some of the needed methodology. I am not sure that I have added more since my earliest postings.

The first question is what really can be done using native dry land vegetation and is there any obvious engineering solutions. Solar driven atmospheric water extraction is a long way from been actually a feasible option although clunky demos have been built.

Before we start, it must be understood that reforesting the Sahara will lead to a far warmer Northern Hemisphere and that this is actually a good thing, It is also reasonable to anticipate the regreening of the entire Middle East. This will generate a warmer but moderated northern Hemisphere. This is one of the greatest single Terraforming tasks left to us to accomplish.

As I have posted earlier, the first step is the building of fenced range lands along the edge of the true desert. That controls the cropping behavior and allows a resurgence of vegetation promoting the retention of moisture. This perimeter culture will migrate backward into the more arable lands and also enhance their productivity. This should tend to encourage an increase in available moisture into the nearby desert lands.

Most critically, it has been shown that the establishment of acacia trees provides shade and a reduction in general temperature increasing the probability of night showers. It has also been shown that such an environment is conducive to the raising of indigenous cattle that are able to graze the developing grasses and possible under story. One would expect that the best strategy would also include other native ruminants that browse more difficult fodder. No goats should be permitted as they will attack and destroy the whole plant.

The idea is to advance this culture into the desert one fence row at a time as the following advance of available moisture accommodates. Without use of artificial means this does promise to take many years. Yet it will still be hugely advanced. The necessary population exists along the entirety of the southern edge of the Sahara with the necessary skills. In most cases it will be a problem of establishing title and supplying barb wire. It will be a lot like the spread of farming on the Great Plains.

We actually know that this was all likely viable grazing land in the beginning that was destroyed over a thousand years. Restoring it this way would likely take another thousand years.

To speed the process up, it should be possible to first design some large water diversion schemes that transfer water into suitable desert regions. It will never be enough but is will expand the watered regions and increase the atmospheric moisture content in those regions, once again allowing a gradual dry land expansion.

The principal prospect for this is the diversion of most of the water in the Upper Congo Basin over to the Chad Basin, perhaps not creating a lake so much as a fully watered basin with a sustainable lake that hopefully is large enough to drain. The possibility would also exist for additional diversion into the north. Work done seventy years ago suggested that this might be feasible.

It is also possible to create a biannual diversion of the Nile west of its current route but this may be of doubtful value until we are in the very late stages.

That then opens the remaining question of whether there is any method to divert some water north from the Niger Valley. At first blush, this appears very unlikely except the rainy season produces a huge amount of water that naturally is lost to the sea. It may be possible to divert sections of that river system to the north into valleys running into the Sahara. There should still be ample water for down river applications.

The truth is that that these engineering options help, but actually for a small fraction of the Sahara. The place is several millions of square miles and it would be a miracle to provide direct irrigation for even a quarter million square miles.

Therefore without actual atmospheric moisture recovery, we are looking at relying on natural recovery aided at least by our direct land management efforts. This might be at the rate of a mile per year, so that you are always followed closely by emergent tree cover. It will require two thousand years at this rate to do the Sahara, and assuming a simultaneous effort in the Middle East, much the same time.

The process may go faster if appropriate grasses can be used.

Greatest Human Ecological Disaster

The global warming debate is driven by growing public unease throughout the world over our visible disregard for good husbandry practices in our industrial economy. It is expressing itself most clearly over the CO2 issue, even though this is most likely a red herring. The direct linkage to global warming is at least controversial, and I for one have a great deal of faith in the Earth’s carbon cycle and its ability to restore such imbalances.

More importantly, the ecological movement is about good husbandry. And strange as it may sound, it is not about conservation. Mankind has already transformed most of the environment to serve its needs thousands of years ago, and mankind’s task increasingly is to improve on this legacy. The only areas that we can rightly conserve are inimical to human habitation and even that often needs the fine hand of good husbandry practice.

With the true wild a policy of haven maintenance must be implemented to properly manage human exploitation. An ideal model of this is to overlay a checkerboard and designate every ninth square as a haven. Of course in practice, this must be negotiated and studied in detail to ensure proper sizing sufficient to the various needs. For example, it makes plenty more sense to preserve old growth forests as a corridor along river beds. Once stake holders understand what is at stake, it can sort itself out quickly.

Let us put this argument in reverse. Extinction is the direct result of a loss of habitat havens. Distributed havens of old growth forests sufficient to support the spotted owl ends threats to that species and as the forests recover their range naturally expands. If we learn to manage havens then our industrial scale exploitation can be recovered from.

Remember, the bison succumbed to the global shoe leather market. Had havens not existed in Canada, the current 500,000 animal herd would simply not exist. Today that herd is on the way back to its millions and people living today will live to see many millions of bison on the prairie because it is simply a better meat animal for that particular climate. I also expect to see the bison introduced into the steppes of central Asia, restoring the native bison hunted to extinction thousands of years ago. That is good husbandry.

It came as a complete surprise to me to learn that the areal extent of the terra preta in the Amazon basin equals that of France. If this is true, then the acreage and the corn and cassava culture would easily have supported massive populations equal to that of contemporaneous India and China. What really stunned me is the fact that if it was not for the soil itself, we would have no evidence whatsoever that such a culture even existed. The Amazon was a lousy place to build permanent structures that could be found in the jungle, although we now will be looking.

What I find most sobering is that tens of millions of individuals have lived theirs lives and passed leaving almost no trace of their existence. How often has this happened globally over the past 10,000 years? Societies do not build with stone unless they are highly organized so a lack of such evidence is very misleading. The so called Stone Age for example did an excellent job of leaving evidence of its existence behind, even though a better name would be the wood and bone age. I have no difficulty setting out to construct a very sufficient tool kit with those two items as the Indians in the Amazon do to this day.

When copper became available and later iron, both metals were too valuable to throw out, so the material was constantly recycled. Yet populations expanded and social complexity increased. The only evidence left would be in the form of pottery. You can also bet that even broken pottery had some commercial value and was largely recycled.

We all know that large populations existed in the Middle East and even Europe, simply because we have looked hard enough. The Sahara desert represents several million square miles and it was once populated and the climate was amenable to agriculture. At least they raised goats. Recall today that the southern edge of this desert currently houses 100,000,000 people in conditions almost as technically primitive as 6,000 years ago on perhaps ten percent of the Saharan littoral. The fools still raise goats.

It has been argued that the collapse of the Sahara was a natural disaster. I suspect that just the opposite is true. It was instead the greatest human caused ecological disaster ever. It is as if China or India disappeared abruptly. Of course we do not know to what extent the desert was fully covered with vegetation. Since an extensive lake system existed I am inclined to err on the side of a nearly one hundred percent coverage, however fragile and terribly susceptible to easy devastation by the grazing of goats.

It is just now in our power to restore this desert back to human agriculture and general fertility just as it is possible to restore the terra preta fields of the Amazon to agriculture. It would be nice to actually absorb that big chunk of solar energy hitting the Sahara and bouncing back out. And a Sahara restored can support a couple of billion people at least.

Athmospheric Water Harvesting

There has been some success in achieving water harvesting from the atmosphere. Efforts have been made to commercially produce a refrigerator like device that also polishes the resultant water making it potable. Obviously a very good idea that will ultimately succeed.

What really made it possible was the fact that the humidity in a living space rises to well over 30% due to water been respired by the occupants. Such a device would replace the direct and expensive haulage of bottled water. In any event it is a great proof of concept and can be done with today's technology.

When you go outdoors, the humidity levels are much more variable, ranging from 15% in the desert to a moderate 30 to 60% in most environments and 100% in some.

Obviously, an environmental level of 15% puts us out of business.. However, one does not start there.

A more appropriate starting point and the best example is the Sahel on the southern edge of the Sahara. There the humidity is a near constant 60% and the local temperature range is about 10 degrees too hot to promote rainfall.

Growing trees there would drop the temperature range that 10 degrees permitting the onset of natural rainfall. A lot of that could be done without any technology at all, and I am happy to report that there is a movement by the locals to begin the process.

Most important though is that once the tree cover is established the high humidity zone advances into the desert, permitting the advance of the tree cover. Just do not let the goats run wild.

Global Terraforming Chapter

This post is an extract from a book I have written titled Paradigms Shift, now been prepared for publication. I will interject additional explanation as we go along in regular type.

Now we come to possible projects that require global investment support and are essentially large enough to be seen as terraforming in their own right. My primary focus is the deserts of the world, which represent 30% of all land surfaces. These can be restored to woodlands by farming water from the atmosphere. It is entirely obvious also that successfully turning the major deserts of the world into productive growing environments will have a significant moderating effect on the global climate.

The areas of interest include all tropical deserts and much of the temperate deserts. In practice, the techniques also apply to major areas deemed as outside the desert zones, yet suffer from droughts and seasonal aridity. In fact there are few places in which agriculture as practiced could not benefit from having alternative water supplies on hand.

In the early stages, we expect that these techniques will be applied in the US southwest and inter mountain region, Northwest China including the Gobi desert and the Sahel in Africa on the edge of the Sahara. All these areas have ample humidity during the dry seasons and a season of rain. Building tree cover that holds that rain and the soils is attractive in terms of expanding the agricultural utility of these regions.

The Sahara Mediterranean ecosystem

The Sahara, the largest single desert on Earth, is possibly the easiest major desert to substantially recover as a successful growing environment. There is good evidence that traditional herding and agricultural deforestation probably accelerated or even caused the original desertification in the first place. Similarly, extensive grazing damage as well as deforestation has caused massive environmental degradation throughout the Mediterranean and the Middle East. Restoring the agricultural potential of the Sahara and the Sahel could easily create millions of new economically viable farms directly employing at least 50,000,000 people with an equal number indirectly engaged. This would be in the early going when urban development is still concentrated on the periphery. In practice I would expect close to a billion people to depend on such a development within two generations.

The primary thrust of any such program is to focus on restoring ground cover, preferably in the form of forest cover, but perhaps more practically early on in the form of commercially valuable scrub plants such as jojoba, which produces a valuable oil berry. The first priority in this program would, through the process of establishing proper tenure, be to finance and generally encourage a recovery where nature can naturally support it.

I recall a report from the Sahel twenty years ago that the simple expedient of putting up a fence was sufficient to establish a green zone. Since then, communities have been making the types of investment necessary to preserve available moisture. This is still an example of cleverly pursuing short-term interests. Growing trees requires some form of effective internal subsidy to carry the tenure holder over in the face of long-term economic benefits and the critical ecological benefits, of which he may simply not live long enough to realize.

[more recently the locals have discovered that encouraging and protecting the growth of acacia trees in combination with cattle raising is hugely beneficial to establishing better fodder and soil conditions]

This is particularly true in areas such as the Mediterranean were hillsides have been totally denuded for a thousand years and forest recovery must be permanent just to restore the soils. Any nominal and sustaining economic benefits will arrive a century hence.

The key technical point to remember is that it is in the nature of things for moisture to be exhaled from plants into the atmosphere. This same moisture can be recycled over and over again as rainfall. We need to help this natural process along.

If we take advantage of the fact that even in the driest desert, the moisture content of the atmosphere is in excess of 13%, it is possible to use refrigeration cycle systems to strip moisture from the air and collect it. If this is used massively, the local environmental moisture itself will be raised, sharply reinforcing the efficiency of the process and improving the water production rate. It is probable that if the Sahara were covered today with the right type of vegetation, that the recycling of atmospheric moisture would be sufficient to sustain the majority of the ground cover with no additional help. This is not true for most deserts which are created in the rain shadow zone of a mountain range.

Modelling water uptake from that of mature apple trees, which are hardly well adapted to the extreme conditions experienced in the desert, we can generate a conservative development model. It is known that such a tree will use and transpire around 70 litres of water per day. We can also reasonably assume such a tree will occupy a footprint with a radius of fifteen feet, which translates comfortably into about fifty trees per acre.

Now it is possible to manufacture and operate a solar driven refrigeration cycle water collector capable of producing 70 litres of water per day. With mass production, such a unit can ultimately cost well below $1,000 and last with minimum inputs for twenty years. Initially it could support a battery of four young trees and as water demand rises, additional units can be added. We have already commented on the advent of solar energy production whose cost per installed watt can be expected to drop below fifty cents per installed watt. Several additional innovations and fixes are also readily available for mass application in the desert environment. We can actually do this.

We can then project in the early going that each developed acre will have an all-in capital investment base somewhere around $50,000. This assumes that each tree ultimately requires one collector. This will also be true only if humidity stays at very low levels. In a large-scale regional development we would expect instead a steady rise in the availability of humidity and even of precipitation, quite capable of increasing production efficiency four fold. The cost per acre could then drop to under $20,000 without additional clever inputs.

I also observe that the initial buildout will usually take place were humidity is already quite high (such as the Sahel) and some distance from the margins of the true desert. As the build out advances into the desert, it will then bring the high humidity and diurnal rainfall with it.

We can plan for full site development, particularly were labour is readily available and cheap as in a home-steading economic model That means clearing a twenty-foot diameter circle by excavating somewhat so that any surface water flows toward the centre. Also a thick layer of organic material, if available, is dug into the circle before been covered slightly with local soil or sands. Water would be delivered from the collector by seepage lines possibly buried in the soil. In the early stages some of this moisture can probably be used to even support a surface cover of grass or alfalfa, which will do an excellent job of binding the soil together and increasing organic content.

This is all initially labour intensive. However, once done it is cheaply maintained. Sudden rainfalls can be captured by these small catchments and absorbed by the imported organic base. Proper design can ensure that the rainfall is concentrated and retained by the roots increasing effective rainfall efficiency. This will augment the solar driven collectors and provide additional security. The manpower needed to maintain such an operation will probably run at one family per twenty acre orchard, particularly if there is the capability to gather unneeded water to support additional small garden plot growing and animal husbandry. Since the maximum base capital investment is about $1,000,000, annual gross sales should reach $100,000 at least. There are crops for which this is possible. A regional program in which water productivity has hugely increased would bring the base capital cost down to under $200,000. This would allow ownership to jump easily to perhaps fifty acres for a family operation with the ability to handle lower value crops. Since the environment is conducive to rapid growth, higher than average productivity can also be expected. The point made is that the putative economics are close enough to feasibility that a massive build out can be entertained, supported by a combination of low interest loans, production subsidies and market stabilisation programs.

From a conventional investment perspective, the asset may take as much as fifty years to pay itself out, though I think this rather unlikely. On the other hand, once created, the asset has a lifespan of thousands of years.

The key aspect of this exercise is that it is technically feasible to cover much of the entire Sahara with trees and the resultant agriculture without irrigation engineering. The technique can also be deployed in any arid environment around the globe creating livelihoods for hundreds of millions of families. This is even true in the tropics were uncontrolled deforestation has induced droughts and falling yields.

This is just the beginning. The whole purpose of covering the arid desert with a tree based vegetation cover in the first place is to increase the total humidity to about one hundred percent. This will cause a diurnal cycle of daytime atmospheric moisture build-up followed by heavy night rain. The real magic of a great forest is that the same water returns as precipitation many times. Thus we can expect that all the great deserts can be turned into hot wet climates, possibly within a generation of the completion of the build out. This means that wild vegetation will actively return to even the truly barren areas within the desert, and the newly developing soils will begin to capture and hold water. Aquifers will replenish and new springs and active riverine systems will emerge. And the agricultural enterprise itself will be partially weaned of the need to use humidity collectors over substantial areas.

There are other technical tricks that can also be used in specific locales. Dewponds can occasionally be built profitably in certain locations, perhaps as a supplemental source of water. Again this is low tech. The stony dessert areas can we windrowed with the surface stones at right angles to the prevailing winds. These windrows can also act as dew catchers as well as unconsolidated roadbeds. The exposed areas between will usually have some sands exposed as a result of the removal of the cover. Additional sand will also blow in with each dust storm. This becomes the growing area for supported trees.

In addition, on the coasts it is possible to build massive greenhouses that integrate seawater as an evaporating water source for supplying ample fresh water for plant growing. Occasional flash floods can also be locally contained and redistributed. As the program matures we will see an expansion of surface runoff and riverine gathering of these waters that can be captured and used to support additional open field farming.

As first suggested fifty years ago the engineers can do one more major trick in the case of the Sahara. It would be feasible to divert a substantial part of the waters of the Congo north into the Lake Chad Basin and on through into the Libyan Desert. This would have a nominal effect in the Congo Basin itself since it is rainforest and is not dependent on the river system maintaining groundwater levels. The Lake Chad Basin could be partially refilled and the surrounding countryside could be fully irrigated, perhaps creating a major rice bowl supporting 100,000,000 people. The evaporating moisture from the huge area covered will also increase precipitation in the direction of the prevailing winds. Surplus water flowing into the Libyan Desert can readily support irrigation farming with enough left over to run into the Mediterranean.

Most irrigation technology is essentially temporary, even if temporary means two thousand years. Shifting to humidity collectors and inducing precipitation will recover even those soils ruined by the salt build up from long-term irrigation. And the trees so chosen should be capable of initially absorbing this overabundance of minerals.

The elimination of arid and desert areas around the globe will lead to a general increase in global precipitation and to a moderation of the climate in both the formerly dry areas and the surrounding climate zones. The absorption of solar energy will also induce a slight drop in average global temperatures. Huge amounts of carbon dioxide will also be taken up and huge amounts of water will be stored in these new ecosystems.

The evolution of this form of water husbandry should be directed toward using the evolved forest as a water retention system and a producer of a water surplus, which finds its best economic expression in supporting irrigated crops of high value. It is not hard to imagine a hundred-acre forest comfortably supporting perhaps twenty acres of cash crop and a small piggery for consuming waste produce. The economic productivity of forests, with the exception of specific orchard plants has a long realization cycle. Shifting the maintenance burden onto the local operator is critical and will require continuous fine-tuning and regulatory guidance. The onset of predictable rains will eventually relieve these operators of much of this burden since fewer collectors will be required.

I expect that a band as narrow as one hundred miles wide to the windward will be sufficient to initiate and sustain the natural precipitation cycle. The degree to which this will augment water requirements down wind can only be guessed at, but it can be expected to be significant. Losses will continuously occur because much rain will fall on barren rock and unusable highlands. Any that falls on the farms will be largely recaptured.

The same technique could also be applied to the more northerly dry zones. However, strong seasonal temperature swings with winter conditions makes this somewhat less attractive. Besides, many of these areas have a successful natural grassland culture, which is probably best left alone.

Northwest China and the Gobi

This area is now stricken with advancing desertification and major dust storms. Yet the land area involved that could be potentially recovered for agricultural purposes is probably over 100 million acres eliminating the dust storms forever. China also has the advantage of having a huge peasant population who would be natural operators of the derivative farms, already having the requisite skills. In addition effective mass production of the humidity collectors in China should quickly reduce the per-unit cost to the lowest possible level. A homestead type program can be envisaged that could mobilize millions of Chinese peasants to work for the opportunity to own a large farm.

A typical farm could consist of fifty acres, out of which forty acres are covered with economically valuable trees supported by humidity collectors. A gathering system, even if the farm starts with only 400 collectors will produce 20,000 to 40,000 liters of water per day plus a substantial amount of electrical power, which can be stored in various batteries. Cheap industrial grade lead-acid batteries, which last forever, come to mind. This provides water for the growing of the trees, but will also diverts surpluses to a central storage for use on the ten-acre plot. Unused water production on the off-season can be stored and used to support wet season field crops and the small garden. Animal husbandry can be steadily integrated into the operation, particularly if the trees are productive in fruits and nuts, as a consumer of waste organics. The wet season should also permit the growth of forage crops in the orchard. The numbers quoted are for illustration purposes. Each district will be engineered at first for the best likely configuration and inevitably modified greatly as the system matures.

China is currently under one political system, which means that this program could be implemented now. The reality is that most prospective terraforming initiatives require the cooperation of several governments. The idea of diverting water from the Congo to Lake Chad is today a near political impossibility. Feasibility is thus irrelevant.

Undoubtedly, once the human imagination recognizes the possibility of constructively terraforming the Earth we will have a flood of great ideas. I personally have no doubt that covering the deserts and semi arid zones with trees as well as restoring former woodlands with economically valuable trees and simultaneously integrating the work with the best agricultural practice will be the single best gift this generation can give the generations of the next millennia.