Carbon dioxide levels

The current debate over controversial global warming theories will continue. The impact of carbon dioxide levels in the atmosphere, whether they are increasing or not over time, and the effect on climate and economics will continue to he discussed. A solution, if it is needed, may evolve—or not. 

Carbon dioxide, considered a wanning gas, comprises about 0.036 percent of the atmosphere by volume. As Figure 1 shows, carbon dioxide levels have increased as a component of the atmosphere by nearly 30 percent from the late eighteenth century to the end of the twentieth century, when the level was close to 365 parts per million by volume. Prior to the period of industrialization, carbon dioxide levels were largely stable, at about 280 parts per million, though fluctuations as low as 200 parts per million or as high as 300 parts per million have been observed through analysis of air bubbles trapped in arctic ice cores. 

Berner, R, A. (1990). Atmospheric carbon dioxide levels over Phanerozoic time. Science, 249, 1382-1386. 

Wigley, T. M. L. (1983). The pre-industrial carbon dioxide level. Climat. Change 5,315-320. 

C05-0130. In 1990, carbon dioxide levels at the South Pole reached 351.5 parts per million by volume. (The 1958 reading was 314.6 ppm by volume.) Convert this reading to a partial pressure in atmospheres. At this level, how many CO2 molecules are there in 1.0 L of dry air at -45 °C ... 

The classical Chinese method consists of inoculating steamed rice grains spread on big trays with a strain of Monascus anka and incubating in an aerated and temperature-controlled room for 20 days. In these types of cultures, moisture content, oxygen, and carbon dioxide levels in the gas environment, as well as cereal medium composition, are the most important parameters to conhol. 

D. B. Ringelberg, J. O. Stair, J. Almeida, R. J. Norby, E. G. O Neill, and D. C. White, Consequences of rising atmospheric carbon dioxide levels for the belowground microbiota associated with white oak. 3. Environ. Qual. 26 495 (1997). 

S. C. van dc Geijn and J. A. van Veen, Implications of increased carbon dioxide levels for carbon input and turnover in soils. Vegetatio I04/I05 2S3 (1993). 

The fact is that, without nuclear energy, any hope of achieving the carbon dioxide levels envisioned by the Kyoto Protocol-or significantly improving the air quality in the U S. or Europe—are severely diminished. In the United States, we would have to double the reductions of carbon without nuclear power to meet the Kyoto goals by the 2007-2012 timeframe. 

Bronchiolar smooth muscle is sensitive to changes in carbon dioxide levels. Excess carbon dioxide causes bronchodilation and reduced carbon dioxide causes bronchoconstriction. Pulmonary vascular smooth muscle is sensitive to changes in oxygen levels excess oxygen causes vasodilation and insufficient oxygen (hypoxia) causes vasoconstriction. The changes in bronchiolar and vascular smooth muscle tone alter the amount of ventilation and perfusion in a lung unit to return the V/Q ratio to one. 

Sozzi GO, Trinchero GD and Fraschina AA. 1999. Controlled-atmosphere storage of tomato fruit low oxygen or elevated carbon dioxide levels alter galactosidase activity and inhibit exogenous ethylene action. J Sci Food Agric 79(8) 1056—1070. 

Fig. 6-1. The response to fossil fuel burning of atmospheric carbon dioxide. The fossil fuel combustion rate is shown at the bottom of the figure, and the calculated carbon dioxide level appears as a solid line at the top of the figure. Observed carbon dioxide values are plotted as triangles (Broecker and Peng, 1982). The observations have been normalized to preindustrial theoretical values.

Ibrahim et al. 1963). Aiken and Braitman (1989) determined that cyanide has a direct effect on neurons not mediated by its inhibition of metabolism. Consistent with the view that cyanide toxicity is due to the inability of tissue to utilize oxygen is a report that in cyanide-intoxicated rats, arterial p02 levels rose, while carbon dioxide levels fell (Brierley et al. 1976). The authors suggested that the low levels of carbon dioxide may have led to vasoconstriction and reduction in brain blood flow therefore, brain damage may have been due to both histotoxic and anoxic effects. Partial remyelination after cessation of exposure has been reported, but it is apparent that this process, unlike that in the peripheral nervous system, is slow and incomplete (Hirano et al. 1968). The topographic selectivity of cyanide-induced encephalopathy may be related to the depth of acute intoxication and distribution of blood flow, which may result in selected regions of vascular insufficiency (Levine 1969). 

Given this state of iron limitation, inputs of iron to the open ocean could result in enough new primary production to lower atmospheric carbon dioxide levels. Because CO2 is a greenhouse gas, cooling of the global atmosphere could result. This potential... 

PAST VARIATIONS IN CLIMATE AND ATMOSPHERIC CARBON DIOXIDE LEVELS... 

Any current warming of the earth is small and is probably quite normal climate variability, (2) There is no noticeable increase in the frequency of extreme weather events, (3) Talk of rising sea levels is alarmist and not supported by data, (4) Despite claims to the contrary, research shows that temperatures and carbon dioxide levels have been higher than today, (5) The current level of carbon dioxide is no cause for alarm,. . . and (7) An increase in the level of carbon dioxide is not the cause of global warming. 

Coplan J, Sharma T, Rosenblum LA Effects of sodium lactate infusion on cisternal lactate and carbon dioxide levels in nonhuman primates. Am J Psychiatry 149 1369-1373, 1992b... 

What scientists cannot determine is what caused carbon dioxide levels to drop in the first place during these icy periods in Earth s history. Some suggest perhaps photosynthesizing plants became too successful and took in too much carbon dioxide, causing less heat to be trapped near the planet s surface and consequently cooling the globe. Thus, while it is known cold climates coincide with low levels of atmospheric carbon dioxide, it is not known why. 

The last big ice age on Earth ended about 12,000 years ago. Today, most scientists believe we are still coming out of that cold period into an interglacial period. An interglacial period is the time between ice ages when Earth is relatively warm. But just as scientists cannot determine why ice ages begin, they cannot determine why they end, either. It is only known that when carbon dioxide levels rise, the Earth starts to get warm. 

D. M. Hunten, Atmospheric evolution of the terrestrial planets. Science 259, 915-920 (1993) J. F. Kasting, Earth s early atmosphere. Science 259, 920-926 (1993) R. A. Berner, Atmospheric carbon dioxide levels over phanerozoic time. Science 249, 1382-1386 (1990) R. A. Berner, Paleozoic atmospheric CO2 importance of solar radiation and plant evolution. Science 261, 68-70 (1993). 

Global warming pressure groups would have the world believe that catastrophic changes in the earth s climate will occur without drastic limitations of carbon dioxide emissions—this in spite of the fact that the carbon dioxide levels in the earth s atmosphere have been much higher than today s for much of geological history. For example, as documented by the work of Berner,13 atmospheric carbon dioxide concentrations were some five 15... 

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