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The Carbon Cycle

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❶Another allotrope that we use every day is graphite, where the carbon atoms are bonded together in sheets of a hexagonal lattice, and fullerenes, where the carbon atoms are bonded together in spherical, tubular, or ellipsoidal formations.

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Element 6: Carbon

Carbon provides the framework for all tissues of plants and animals. They are built of elements grouped around chains or rings made of carbon atoms. Carbon also provides common fuels--coal, oil, gasoline, and natural gas Showed first characters. Showed next characters. For your convenience Manyessays provide you with custom writing service. All papers are written from scratch by only certified and experienced writers.

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Oxygen has many uses - it is used in welding torches, to assist in hospital patient's breathing and in metal fabrication industries In the Experiment Station Record for , the Department provided a summary and translation of the experimental work of M. Demoussy, originally published in French in In the early 20 th century Demoussy performed an experiment in France demonstrating the effects of carbon dioxide on a variety of plants.

These experiments were an early demonstration of the benefits of carbon dioxide enrichment. The author has repeated his experiments with 16 species of plants, representing a wide range of families. Duplicate series were grown, one in normal atmosphere containing about 3 parts of carbon dioxide in 10,, and the other series in an atmosphere enriched daily by about five times the normal quantity of carbon dioxide.

The experiments were continued for about 2 months, after which several portions of the plants were weighed. Among the species studied were coleus, lettuce, geraniums, centaury, mint, tobacco, balsam, fuchsias, etc.

In all except the fuchsias there was a decided increase in the weight of the plants, the average amounting to over 60 percent increase. In addition the geraniums, begonias, mints, etc. For the original article in French see Demoussy, M. The control group of plants was exposed to the ambient CO 2 concentration, at that time measuring about parts per million. The experimental group was exposed to 5 times that amount, or about parts per million. At the end of two months the average increase in the weights of the various species of plants exposed to CO 2 enrichment as compared with control groups was over 60 percent.

In other words the plants responded exuberantly to the increase in their food supply and thrived strikingly. Wittwer and Robb, referenced above, discuss an early experiment that demonstrated the positive effects on plants of carbon dioxide enrichment, citing the work of M.

Jones in , published in the Vermont Station Bulletin. Augmented supplies of carbon dioxide were supplied for 8 hours each day to plants growing in open boxes. Wittwer and Robb summarized the findings of Cummings and Jones: Yields of pods and seeds were enhanced in peas and beans. Potatoes produced more leaves and tubers.

Large and heavier leaves were formed by foliage crops. Lettuce was very responsive. Flower crops produced blossoms earlier and in great profusion. Strawberries yield fruit far in excess of the controls. Wittwer and Robb also mention that extensive experimentation was being conducted in Europe as well. They note that some of these experiments showed that the yield of some food plants such as tomatoes and cucumbers was doubled, or even tripled, by the addition of CO 2.

In the s botanists with the Department of Plant Physiology and Pathology, Imperial College of Science and Technology, London, designed and constructed apparatus to improve standardization of testing, which prior to this time lacked sufficient controls to perform a reliable statistical analysis. Annals of Botany , Vol. The results of their initial testing were published in Fischer published the year before: Increased greenness has been observed throughout the above series of experiments.

An increase is evident within two or three days from the beginning of the experiment. These results are quite extraordinary.

This report described a series of experiments conducted from to at the Plant Science Greenhouses at Michigan State University with a variety of crops grown in containers. In this study they remark that:. Alternatively, carbon dioxide levels in plant growing atmospheres maintained substantially above the normal should favor growth.

Two points should be emphasized here. First — the authors advise that, because of the great demand by plants for carbon dioxide, it is likely that in a greenhouse environment the atmosphere might quickly become depleted in this essential gas to the extent that it begins to impede plant growth, supporting the idea that ambient atmospheric amounts of CO 2 are, in point of fact, precariously low relative to the requirements of the biosphere, a point I will come back to later in this essay.

Second — plant growth could be stimulated through enrichment of carbon dioxide in the greenhouse atmosphere with potential economic benefit. The authors go on to describe the results of experiments in the tank culture of algae in which it was found that:. In fact, carefully controlled experiments, the results of which for many plant species have now accumulated, show that neither the normal carbon dioxide concentration of the air, nor this gas in water. The authors are here pointing out that normal carbon dioxide amounts in both air and water are not sufficient for maximizing photosynthesis.

In other words, the plants could readily consume a great deal more carbon dioxide than they presently are under ambient conditions. There is an important implication here. The following photographs from Wittwer and Robbs report dramatically demonstrate the remarkable effects of CO 2 enrichment on a variety of plants. These show only a few of the many similar experimental results but are typical. Tomatoes grown in a controlled environment with CO2 concentrations varying between and ppm.

Present global atmospheric concentrations are right at ppm. Compare with the next image. Tomato plants grown in an environment with CO 2 concentrations varying between and ppm, that is, 2x and 5x the current atmospheric concentration. From Wittwer and Robb In the image below Wittwer and Robb show results of carbon dioxide enrichment on several plant varieties after 30 days.

The plants in the top row are leaf lettuce, second from the top is bibb lettuce, second from the bottom are tomato plants and the bottom is cucumber. The column on the left are plants grown in an environment with approximately parts per million carbon dioxide, similar to the present concentration, and the column on the right shows plants grown with ambient CO 2 concentrations of ppm. The difference in growth is obvious and impressive.

Table 1 below from Wittwer and Robb displays the effects on 8 varieties of lettuce. In every case the weight of the lettuce variety grown in an enriched environment was substantially greater. Experiments were also performed on a variety of tomatoes with the results shown below in Table 4 from Wittwer and Robb. Again, the remarkable effect on yield is impressive. In summarizing their experiments, conducted at the Plant Science Greenhouses at Michigan State University, Wittwer and Robb discussed the effects on growth and development they observed during their experiments:.

Tomato fruit yields were significantly increased. Fruit harvest was more consistent and less subject to fluctuating outdoor weather. Size and fruity quality were enhanced. Our data for cucumbers are supported by those of Daunicht where percent increases in fruit production were several fold greater than those for vegetative growth.

More rapid growth rates, from carbon dioxide enrichment of a greenhouse atmosphere, have resulted in earlier maturity and higher yields of lettuce. Three crops of lettuce in place of two during fall, winter, and spring production are possible. Other benefits from growing crops in high levels of carbon dioxide in a greenhouse atmosphere have been reported. The percent dry matter is increased. The essential oil content has been enhanced.

Rooting of cuttings was favored. Tomatoes had a higher vitamin C and sugar content, and plants were more resistant to some fungus and virus diseases and insects. In the conclusions to their report Wittwer and Robb confirm that their findings were similar to previous studies that found a substantial enhancement of plant growth.

They made reference to Dutch botanist C. Briejer who published the results of his studies on plant responses to increased carbon dioxide concentrations in with the title Een verlaten goudmijn: The authors conclude by emphasizing the benefits to be realized by commercial greenhouse operators with the employment of carbon dioxide enrichment:.

The production potential for greenhouse grown vegetable crops of the future is comparable to that which appeared a century ago when the agronomic benefits of chemical fertilizers were first realized. The ultimate possible rewards are so great that growers of greenhouse vegetables can begin immediately to use and to benefit from the results of the research findings herein reported.

I will return to that question. After 21 more years of study, one of these authors, the late Sylvan Wittwer, who passed away in at the age of 95 reiterated the fact that there were benefits to the increase in atmospheric carbon dioxide.

But then he went on to say something else very interesting. Strain pondered the effect of the increasing supply of CO 2 on the planetary vegetation realm and speculated that:. Current data indicate that plants growing at higher than normal CO 2 levels are more tolerant of water, temperature, light, and atmospheric pollutant stresses.

There are effects on carbon metabolism, plant growth and development, microbial activity, and terrestrial and aquatic plant communities. Strain Carbon dioxide levels in the biosphere: Effects on plant productivity: Critical Reviews in Plant Sciences , vol. We will come back to this question directly, and see that now, in , we do have enough data to draw some conclusions.

Returning to the subject of carbon dioxide utilization in greenhouses, we will turn to a report by the Economic Research Service with the U. I will quote at length from that report:. Below-normal levels of CO 2 , often found in unventilated greenhouses, can reduce the rate of photosynthesis , while above-normal levels can hasten photosynthetic activity. The reason below-normal levels of carbon dioxide occur in unventilated greenhouses is that the plants will quickly consume all available CO 2 as they grow and unless the supply is replenished it will then diminish to levels insufficient for continued photosynthesis, thereby stunting further plant growth.

The Review goes on to discuss the upsurge in CO 2 utilization in greenhouses in the s due to development of safe and economical combustion sources of CO 2 along with monitoring devices and plastic tubing for distribution and circulation. These innovations led to a major increase of testing and experimentation. The Review describes the situation in Europe at the time:. It started in February when a grower used a small paraffin kerosene oil warming stove during the daytime hours on lettuce and obtained exceptional quality and weight: Followup work at the Glasshouse Experimental Station in Naaldwijk showed outstanding results on lettuce and strawberries and good results on tomatoes, endive, spinach and radishes.

The weight of the lettuce was increased and growth accelerated by 20 to 30 percent. By , the total area treated in Holland was about 7, acres. Increases of 30 percent in lettuce yields were obtained; the following winter the figure rose to 70 percent. Increases in tomato yields ranged from 25 to 70 percent, depending on variety, and average 43 percent.

CO 2 proved to be especially effective in midwinter because crops in non-ventilated houses quickly utilize most of the available CO 2 during the early morning hours and thereafter receive little benefit from sunlight. A study on four plant species was conducted using transparent open-topped chambers placed in fields. A high-pressure manifold allowed control of the ventilation airstream to generate three different CO 2 concentrations.

The tests were conducted by three botanists and the report describing the tests and their results appeared in the journal Science. Through photosynthesis, plants form the support system for the rest of the biosphere. Since carbon is a chief input in the food producing process, any appreciable response of plants to changing CO 2 concentrations could have far-reaching implications. The four species upon which the tests were conducted were corn, soybeans, loblolly pine and sweetgum trees. The plants were grown in pots and exposed to the different levels of CO 2 for a period of three months.

All plant treatment protocols such as watering, fertilizing and light exposure were controlled and kept consistent.

The carbon dioxide concentrations varied between and ppm. The results of the test was that:. Yield increased for the two crop species and wood volume increased for the tree species.

Wilting on hot afternoons inhibits leaf expansion and photosynthesis at a time when other environmental factors are most favorable for rapid carbon fixation. Thus a corn plant growing in an atmosphere with a high level of CO 2 was able to continue fixing carbon and avoided wilting even though it had a greater leaf area. At ppm CO2, leaf thickness in these three species was , and percent of the control values, respectively. Thickness increased in all of the cell layers of pine and sweetgum leaves.

In soybeans the greatest effect was the appearance of a well-developed third layer of palisade cells. The appearance of a third layer of palisade cells is quite remarkable. Observe the image below from Wikileaks Common. The palisade is the vertically oriented row of cells containing the chloroplasts that is situated just below the upper epidermis of the plant. It is one of two layers comprising the mesophyll layer of the leaf which serves as the primary zone of photosynthesis due to the high concentration of chloroplasts.

The main function of the palisade cells is the absorption of light by means of their chloroplasts, which are chlorophyll containing organelles, or sub-units, that absorb carbon dioxide and light energy during photosynthesis. The palisade cells containing the chloroplasts is typically one to two layers thick and is arranged in rows from one up to five in number.

So now consider how remarkable it is that under a CO 2 enhanced atmosphere the leaves of soybeans will construct a whole additional palisade layer of chloroplast containing cells allowing for enhanced light absorption. By scientists were beginning to suspect the possibility that enhanced concentrations of CO 2 may have been stimulating photosynthesis on a global level. But there is another point they make, one which reveals the remarkably important relationship of carbon dioxide to the health of plants, for by this time studies were revealing that in addition to growth stimulation, plants growing in a CO 2 enriched atmosphere were more able to tolerate a variety of stresses, including water deprivation, light deprivation, temperature changes, and pollution, which I will discuss further.

Another important study was published in with a summary of research up to that date. The author was Bruce A. Kimball, a soil scientist with the U. Water Conservation Laboratory, Phoenix. His primary interest in this study was the effect of increasing CO 2 concentration on agricultural yields.

To that end he painstakingly compiled observations on 37 different plant species grown under an enriched CO 2 environment. The results of these observations, conducted over 64 years, were published in 70 different reports evaluated by Kimball. He points out that most of the studies were performed in greenhouses and growth chambers.

Extracting the data from these 70 reports Kimball included extensive appendices with his report. So, in quantitative terms, what does this overwhelmingly positive effect on yield translate into?

Certainly more data are needed for the major crops. Considering the variability inherent in such work, however, the large body of prior experimental data is sufficiently representative to provide a more reliable prediction of future CO 2 effects. Food would become significantly more abundant. More yield per acre could be achieved, meaning more food from less land to feed the global population.

He has authored or co-authored over scientific papers, has performed numerous experiments and has conducted extensive research into the biospheric and atmospheric effects of carbon dioxide. Professor Idso is still active and has become a provocative figure in the climate change controversies because of his willingness to acknowledge a beneficial aspect to carbon dioxide enrichment, along with his belief that increasing carbon dioxide is not going to have a dangerous effect on the climate. His research is worth delving into further and directly I will review an important experiment he performed in the late s.

About observations of the yields of 37 plant species grown with CO 2 enrichment were extracted from the literature and analyzed. Another 46 observations of the effects of CO 2 enrichment on transpiration were extracted and averaged. A gricultural Water Management , vol. It has also become apparent that efforts are being made to downplay the positive effects of carbon dioxide by arguing that there are limits to the fertilization effect upon plants.


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- Introduction This paper examines the implications of using different approaches when it comes to accounting for carbon emissions. This essay provides a brief background on the Kyoto protocol. Then it goes into the issues surrounding accounting for carbon.

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Oct 18,  · Carbon Carbon is the fourth most common element in our universe, and the second most common element found in our bodies. Carbon comes in the .

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The carbon cycle can be defined as the continuous biological process through which the carbon is exchanged between the environment and the organisms. It also refers to the thermonuclear reactions which are brought about by nucleus of a carbon atom when it absorbs protons. Essays from BookRags provide great ideas for Carbon essays and paper topics like Essay. View this student essay about Carbon.

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Reducing the Carbon Footprint Essay example Words 4 Pages Because carbon footprints are such hot topics in the news these days, it's an ideal topic for this particular paper. Carbon Essays: Over , Carbon Essays, Carbon Term Papers, Carbon Research Paper, Book Reports. ESSAYS, term and research papers available for UNLIMITED access.