Photosynthesis

The world’s hot deserts can grow vegetation when irrigated. As this vegetation grows it improves the sparse desert environment by increasing water and nutrient capture. These in turn increase growth in a positive feedback loop that can lead to desert recovery much more quickly than was previously expected.

The greater the rate of growth of plants the more CO2 they are capable of sequestering.

Plants grow by the fundamental process of photosynthesis. The chemical formula of which is H20 + CO2 + Radiant Energy = C6H12O6 + 02.,

Or as depicted to the right. water + CO2 + Solar Energy = Sugar + Oxygen.

Chlorophyll is vital to the photosynthesis process because it allows plants to obtain energy from light. Chlorophyll molecules are specifically arranged in and around pigment protein complexes called photosystems, which are embedded in the thylakoid membranes of chloroplasts. Chlorophyll absorbs light most strongly in the blue and red but poorly in the green portions of the electromagnetic spectrum, hence the green colour of chlorophyll-containing tissues like plant leaves.

The sugar produced in photosynthesis is the building block for all plant growth and therefore all higher forms of life on earth.

For every unit of CO2 used in photosynthesis the plant loses about 600 units of H2O. This is known as transpiration ratio or water use efficiency and usually varies between 100 and 1000, depending on the environmental conditions.

Continued hydration is essential for plant growth therefore in present desert conditions, where hydration is sporadic at best, for the most parts plants do not grow.

Deserts are excellent sources of light energy to drive the photosynthesis process but the other key ingredient, water, is missing. The desalination of water, by the means described above, would provide the missing ingredient for plant growth in the world’s hot deserts, where the plant growth in turn can sequester large quantities of CO2.

Photosynthesis is far and away the best reducer of atmospheric carbon. Annually it takes up 110 billion gigatons of carbon.

The world has a landmass of 148 million km². Of this mass 43 million km² is desert where vegetation is virtually non existent. The landmass that supports vegetation is therefore 148 million km² - 43 million km² or 105 million km² upon which 110 billion gigatons of carbon are taken up annually. It is an objective of the current invention to make a portion of the world’s hot deserts capable of supporting plant life, which will then sequester carbon. These deserts cover 15.6 million km² of the Earth’s surface. This area has the potential to sequester 15.6/105 or 14.8 percent more carbon or an additional 16.3 gigatons of carbon annually. This would over turn the atmospheric carbon balance sheet with the result as much as 10 gigatons more carbon would be taken out of the atmosphere than is input. This would not be a desirable consequence of implementing the current invention over the long-term but shows that balancing the carbon balance sheet may not be as problematical as is currently perceived. This balance may be achievable quite readily at an acceptable cost by using one or a number of aspects of the current invention in tandem.

In the short-term it might be beneficial to take up more carbon from the atmosphere than is being emitted until such time as the 280 parts per million (ppm) pre-industrial levels are restored. If climatic events dictate this lowering of CO2 levels in the atmosphere is necessary this aspect of the current invention would afford the means to accomplish this reduction.

Deserts can produce a variety of edible plants as well as plants that can be converted to wearing apparel or for use in construction.

For example the Sahara 50 desert is home to several species of plants that nourish its residents, and provide a lucrative business opportunity. Five plants in particular are most frequently cultivated and eaten in the Sahara these are; orange trees, the herb thyme, figs, the fruit magaria and olive trees.

Bamboo is the fastest growing woody plant on the planet and thus has the potential to sequester the most CO2, the fastest.

Bamboo is the fastest growing canopy for the regreening of degraded areas and generates more oxygen than equivalent stand of trees. It lowers light intensity and protects against ultraviolet rays and is an atmospheric and soil purifier.

A viable replacement for wood, bamboo is one of the strongest building materials. Bamboo's tensile strength is 28,000 per square inch versus 23,000 for steel.

In a plot 20m x 20m2, in the course of 5 years, two 8m x 8m homes can be constructed from the harvest of bamboo and every year after that the yield is one additional house. It is also a source of food and provides nutrition for millions of people worldwide. Some species make fodder for animals and food for fish. Taiwan alone consumes 80,000 tons of bamboo shoots annually constituting at $50 million industry.

Bamboo’s hardiness is demonstrated by the fact it was the first vegetation to grow in Hiroshima after the atomic blast of 1945 and there are a number of drought hardy bamboos, including Bambusa tuldoides, Phyllostachys mannii, Pseudosasa japonica, Bambusa multiplex, Bambusa oldhamii, Otatea acuminate aztecorum, Bambusa dissimulator, Phyllostachys rubromarginata and Sasaella masamuneana suited to growing in an irrigated desert environment.

Hemp is another potential cash crop that is both rapidly growing and can be planted in desert conditions. It is also said to both stabilize and enrich soil, as desert soils require to become more productive.

Hemp plants have deep tap root system, which enable the plant to take advantage of deep subsoil moisture, which is not as susceptible to evaporation, which is a major impediment to growth in hot deserts.

Hemp has been produced for thousands of years as a source of fibre for paper, cloth, sails/canvas and building materials. Natural fibre from the hemp stalk is extremely durable and can be used in the production of textiles, clothing, canvas, rope, cordage, archival grade paper, paper, and construction materials.

The demand for renewable raw materials is increasing. Currently many companies produce non-woven products like mats for insulation and car/vehicle composites based mainly on flax but increasingly now on hemp fibres. Hemp fibres have excellent potential – they can reinforce plastics, substitute mineral fibres, be recycled, can be grown ecologically, and have no waste disposal problems. A range of products can be derived from non-woven mats for a range of uses: insulation, filters, geotextile, growth media, reinforced plastics and composites.

Hemp is not only absorbent; it is rich in silica. When mixed with lime, hemp fibres change from a vegetable product to a mineral. In this mineral state it is often referred to as hemp stone, and it weighs between 1/5 and 1/7 that of cement based concrete. Several hundred houses have been built in Europe using this material. Research is ongoing in the UK and Germany, where hemp has been used for the construction of floors since the mid 1900s. Sometimes the hemp is mixed with lime, water and either gypsum or river sand. When poured it hardens, and becomes mould and insect resistant. It can be used in drywall construction between formwork, as an interior and exterior insulation or be poured as a floor. The formwork can be removed within a couple of hours.

The techniques for desert agriculture is well know and do not form a part of this inventive concept. It is an objective of the current invention however to facilitate sufficient growth in the world’s hot deserts to overcome and/or reverse the annual build-up of atmospheric carbon.