Climate change, global

Of course, such a flow diagram cannot accurately portray the complete climate-biogeochemical cycle system. Rather, diagrams such as this are intended 

Copyright 1992 Academic Press Limited All rights of reproduction in any form reserved 

FIGURE 1.7 Average total column ozone measured in October at Halley Bay, Antarctica, from 1957 to 1994 (adapted from Jones and Shanklin, 1995). 

In short, although the history of anthropogenic perturbations to the stratosphere is much shorter, it is clear that these are also important. Indeed, such perturbations are expected to affect the chemistry of the troposphere as well for example, increased UV radiation will alter photochemistry at the earth s surface. 

After the first reports of this phenomenon, major field campaigns were launched, which clearly established a relationship between ozone destruction and chlorine chemistry. For example, Fig. 1.8 shows simultaneous aircraft measurements of ozone and the free radical CIO as the plane flew toward the South Pole. As it entered the polar vortex, a relatively well-contained air mass over Antarctica, 03 dropped dramati- 

FIGURE 1.8 Measured concentrations of the chlorine monoxide free radical (CIO) as well as 03 outside and inside the polar vortex on August 23, 1987 (adapted from Anderson, 1989). 

Destruction of stratospheric ozone caused by relatively small atmospheric concentrations of chlorofluo-rocarbons has vividly illustrated the capacity of human activity to alter our atmosphere in a manner that has significant and far-ranging effects. There is similar concern for the effects of greenhouse gases on the earth s climate. 

Robert J. Charlson, Gordon H. Orians, and Cordon V. Wolfe 

For thousands of years of human history, it was assumed that the biosphere was so enormous that nothing human beings could do would alter it in any significant way. Although it was true that pollution had become an issue, pollutants from automobile exhaust, fossil fuel power plants, and factories were fairly localized problems. All that was needed was a good strong wind for a few days, and those problems would go away. 

Toward the latter part of the twentieth century, however, that attitude began to change. The threat to the protective shield of ozone in Earths stratosphere was a wake-up call to the reality that human activity could lead to the destruction of life on Earth. Recognition that Earth s oceans are not an unlimited reservoir for our garbage and sewage was another wake-up call. 

During the Cold War, the threat of nuclear warfare on a global scale lead to the sobering realization that humans really do have the potential to cause the extinction of the human race, if not all life on Earth. The specter of accelerated global warming was added to the list of threats to the continuation of human existence along with many other species that are as vulnerable, or even more vulnerable, to the deleterious effects of a significantly hotter planet. 

So what is dilferent about the current warming trend Why have cUmate scientists been so much in the news for at least a decade crying that Earth is getting too hot Why did former Vice President A1 Gore receive the Nobel Prize for his efforts to educate people about global warming  

For thousands of years humans believed that the atmosphere and the oceans are so enormous that they could not be impacted by human activity. Only in the past half century have we learned otherwise. 

A FIGURE 6.13 The Rise in Atmospheric Cariwn Dioxide Atmospheric carbon dioxide levels have been steadily increasing as a result of fossil fuel combustion. 

EXAMPLE 6.13 Fossil Fuels and Climate Change One way to evaluate fuels with respect to global warming is to determine how much heat they release during combustion relative to how much CO2 they produce. The greater the heat relative to the amount of CO2, the better the fuel. Use the combustion reactions of carbon, natural gas, and octane, in combination with the enthalpy of combustion for each reaction (aU given earher), to calculate the heat (in kJ) released by each fuel per 1.00 kg of CO2 produced.  

SORT You are given the mass of CO2 emitted and asked to find the energy output for three different fuels. GIVEN 1.00kgCO2 FIND kJ  

The conceptual plan has two parts. In the first part, use the molar mass of CO2 to convert from mass of CO2 to moles of CO2. This step is the same for each fuel. 

In the second part, use the stoichiometric relationship between moles of CO2 produced and kilojoules of energy released to calculate the energy output. Repeat the second part for each fuel using the appropriate stoichiometric relationship from the balanced equations. 

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The Royal Society (London), The Greenhouse Effect the scientific basis for policy. Submission to the House of Lords Select Committee, 40 pp. (1989). See also Global Climate Change, Information Pamphlet (12 pp.) i.ssued by the American Chemical Society (1990) B. Hileman, Global Warming, Chem. Eng. News, April 27, 7-19 (1992) and references cited therein. 

Geller, H. S., and Goldstein, D. B. (1999). Equipment Efficiency Standards Mitigating Global Climate Change at a Profit. Physics Society. 28(2). 

Burning fossil fuel releases carbon into the atmosphere—more than 6.3 billion tons in 1998 alone. Significant amounts of carbon also come from burning of live wood and deadwood. Such fires are often deliberately set to clear land for crops and pastures. In 1988 the smoke from fires set in the Amazon Basin covered 1,044,000 square miles. By far the most serious implication of this is the significant threat to Earth s ecosystems by global climate change. 

Part of the concern about global climate change stems from the human tendency to seek meaniiig in events that may or may not be more than simply a random event. A particularly cold winter, a particularly hot summer, an especially rainy season, or an especially severe drought will all send people off on a search for the greater meaning of the phenomenon. Is it a pattern, or a one-time event Must we build a dike, or has the danger passed Since the summer of... 

Finally, increases in the intensity or variability of weather are considered another form of indirect evidence reflecting whether Earth is currently undergoing human-driven climate change. Predictions of increased incidence of extreme temperatures, tornadoes, thunderstorms, dust storms and fire-promoting weather have been drawn from basic global climate change theoiy. However, evidence has not so far borne out these predictions on a global scale. The IPCC concludes ... 

Concerns about global climate change have led to extensive research and high-level international debates about the need for targets and timetables to reduce carbon dioxide emissions. Some policymakers believe that current uncertainties in how to approach the issue do notjustify an all-out effort to reduce carbon dioxide emission, while others feel that this is a crisis needing immediate attention. 

Concerns about global climate change have motivated new interest in low-carbon or noncarbon fuels. Recent rapid progress and industrial interest in low-temperature fuel cells (which prefer hydrogen as a fuel) for transportation and power applications have also led to a reexamination of hydrogen as a fuel. 

The ability to incorporate spatially explicit information that will couple these site-specific responses to global climate change is critical to summarizing the impact these site-specific feedbacks to global-scale feedbacks. 

Broecker, W. S. (1994). Massive iceberg discharges as triggers for global climate change. Nature 372, 421-424. 

Cao, M. and Woodward, F. I. (1998). Dynamic responses of terrestrial ecosystem carbon cycling to global climate change. Nature 393,249-252. 

Global climate change will occur slowly and gradually. 

Molnar, P. and England, P. (1990). Late Cenezoic uplift of mountain ranges and global climate change chicken or egg Nature 346, 29-34. 

Global Global climate change Stratospheric ozone depletion... 

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