Showing papers on "Carbon cycle published in 1973"

Industrial production of carbon dioxide from fossil fuels and limestone

Abstract: The release of carbon dioxide into the atmosphere by the burning of fossil fuels is significantly altering the carbon cycle by adding to the amount of carbon in the atmosphere and in the more rapidly interacting portions of the biosphere and oceans. In order better to assess these changes, the basis for calculating global CO 2 emissions is reviewed and new annual values are computed for the period 1800 through 1969. The world average fractions of carbon in coal and lignite, estimated from calorific data, are found to be lower than previously assumed. When account is taken of handling losses and partial diversion to produce petrochemicals, road asphalt, and other non-fuels, the calculated CO 2 emissions are further reduced by several percent even after allowing that most unburned materials eventually oxidize to CO 2 in the environment. On the other hand, the production of CO 2 by kilning of limestone adds 1 to 2% to the annual totals. The cumulative increase in carbon in the short term carbon cycle, owing to man's industrial and domestic activities up to 1970, is estimated to be 1.12 + 0.14 times 10 17 g (4.1 + 0.5 times 10 17 g CO 2 ), or about 18% of the amount of CO 2 in the atmosphere during the late nineteenth century. DOI: 10.1111/j.2153-3490.1973.tb01604.x

Atmospheric carbon dioxide and radiocarbon in the natural carbon cycle: II. Changes from A. D. 1700 to 2070 as deduced from a geochemical model.

Abstract: From carbon and the biosphere corference; Upton, New York, USA (16 May 1972). In carbon and the biosphere. A noniinear geochemical model of the interaction of atmospheric CO/sub 2/ with the oceans and land biota has been constructed to predict future changes in atmospheric CO/sub 2/ concentration in the next century. If production of CO/sub 2/ from fossil fuels continues, the perturbations from preindustrial times may become so large that a linear model is unrealistic, especially because it fails to take into account that ocean surface water will become progressively more acid and less able to absorb each new increment of industrial CO/sub 2/. On the assumption that industrial CO/sub 2/ production continues to increase at the rate of the past 20 years and that the ultimate increase in biomass of the land biota is no more than twice the present biomass, the atmospheric CO/sub 2/ concentration will reach a value six to eight times the preindustrial value in 100 years. When the /sup 14/C concentration in dated wood and the recent atmospheric increase in CO/sub 2/ are compared in the cortext of the model, it appears that the land biomass has increased 1 to 3% since the beginning ofmore » the industrial era. This calculation takes account of the actual year to year variations in industrial CO/sub 2/ production and the heliomagnetic variation in /sup 14/C production in the stratosphere. The inferred biomass increase, presumably owing to CO/sub 2/ fertilization, is too small to be verified by direct observation and is not considered to be established. On the other hand, the trend in atmospheric CO/sub 2/ apparently rules out any large recent change in biomass. (auth)« less

The Carbon Dioxide Cycle: Reservoir Models to Depict the Exchange of Atmospheric Carbon Dioxide with the Oceans and Land Plants

Abstract: The following survey of carbon dioxide in nature places major emphasis on describing how the injection of CO2 into the atmosphere by man’s industrial activity has perturbed the natural carbon cycle on a global scale. In a sense, this injection is a mammoth geochemical experiment. It permits us to observe the transient response of the air, the oceans, and the biosphere to a major disturbance taking place over the interval of only a few years. Our quantitative understanding of the carbon cycle is thus repeatedly challenged and refined.

Chemistry of the lower atmosphere

Abstract: The presence of particulate matter in the lower atmosphere is considered, giving attention to the sources of particles in the troposphere, the composition of particles collected from the atmosphere, aspects of particle concentrations and size distributions, mechanisms of removal, residence times, and conditions in the lower stratosphere. The role of natural and anthropogenic pollutants in cloud and precipitation formation is discussed together with removal processes of gaseous and particulate pollutants, and the global sulfur cycle. Other topics examined include the chemical basis for climatic change and the carbon dioxide cycle. Individual items are announced in this issue.

Carbon Cycles and Temperate Woodlands

Abstract: The other chapters of this book have shown many ways of linking different parts of the same system to one another. Among the ways of linking the world’s regional and local systems to one another, unifying considerations of the circulation of carbon (and of nitrogen) through a common atmospheric pool have been recognized as important since Dumas and Boussingault (1844; see Riley, 1944). Even now we are not sure how important lands, especially forests, can be in modifying or stabilizing these cycles, but several kinds of information and models suggest that their importance may have been underestimated in the past (Figs. 1 and 2).

The carbon dioxide system in the oceans

Abstract: A model of the carbon dioxide system in nature is derived and is used to further our understanding of the factors which control this system in the oceans, the atmosphere, and the sediments.

Samsara of organic carbon

Abstract: A summary is presented of results obtained in the study of the organic matter contained in sediments. The evolution of this organic matter with age is discussed and its importance is emphasized for the understanding of processes occurring during diagenesis. Organic Geochemistry is a recent Science: a well-documented review published in 1971' lists some 300 references, half a dozen of which refer to papers published before 1945. Reviews"2 and monographs3 have put on record present results and the philosophy of the work, so that we can dispense with a balanced presentation. I shall only give a personal description of our present approach to organic geochemical problems, with no attempt at showing how much more the field owes to other groups, such as those of Calvin, of Eglinton, and of many petroleum companies. A global survey. Most argillaceous sediments studied so far contain some one or two per cent of organic carbon, be it a 'recent' sediment (say, from the Tertiary) or a 'very old' one (say, from the late Precambrian). A small mountain, 100 m high and 1 x 1 km large, may contain some 4 x 106 tons of organic carbon in its minerals; on its surface, if densely covered by vegetation, it may bear only some iO tons of carbon in living trees, plants, animals and micro-organisms: less than one thousandth of its fossil carbon. Such is the result of imperfect recycling. As organisms die, their organic matter decays, and their carbon returns to its most stable form in an oxygencontaining atmosphere: not dust, but carbon dioxide. This leads to the first, short lived, carbon cycle, followed in months or years. Recycling would be accomplished through re-use by photosynthesis, were it not for a flaw: this 'quick' cycle leaks into a second cycle, a long-lived one, followed in aeons. A small portion of organic matter escapes decay, and is buried with carbonates or silicates into sediments. It is preserved until orogenesis and erosion bring it back to the surface (Figure 1). One estimates the total mass of organic carbon accumulated in sediments at some 6 x 1015 tons—the mass of organic carbon present in living organisms at 3 x 1012 tons. Organic Chemists should therefore mostly study rocks! I shall restrict this report to our work on two lacustrine sediments, oil shales found near Strasbourg, in Messel (Germany) and Bouxwiller (France).