File Name: air pollution and global warming history science and solutions .zip
- What is climate change? A really simple guide
- Global Warming
- Air Pollution and Global Warming: History, Science, and Solutions
While Covid has shaken much of human society, the threat posed by global warming has not gone away. Human activities have increased carbon dioxide emissions, driving up temperatures.
Changes in climate can result in impacts to local air quality. Atmospheric warming associated with climate change has the potential to increase ground-level ozone in many regions, which may present challenges for compliance with the ozone standards in the future. The impact of climate change on other air pollutants, such as particulate matter, is less certain, but research is underway to address these uncertainties. Emissions of pollutants into the air can result in changes to the climate.
What is climate change? A really simple guide
The history of the scientific discovery of climate change began in the early 19th century when ice ages and other natural changes in paleoclimate were first suspected and the natural greenhouse effect was first identified. In the late 19th century, scientists first argued that human emissions of greenhouse gases could change the climate. Many other theories of climate change were advanced, involving forces from volcanism to solar variation.
In the s, the evidence for the warming effect of carbon dioxide gas became increasingly convincing. Some scientists also pointed out that human activities that generated atmospheric aerosols e. During the s, scientific opinion increasingly favored the warming viewpoint.
By the s, as a result of improving fidelity of computer models and observational work confirming the Milankovitch theory of the ice ages, a consensus position formed: greenhouse gases were deeply involved in most climate changes and human-caused emissions were bringing discernible global warming.
Since the s, scientific research on climate change has included multiple disciplines and has expanded. Research has expanded our understanding of causal relations, links with historic data and ability to model climate change numerically.
Research during this period has been summarized in the Assessment Reports by the Intergovernmental Panel on Climate Change. Climate change , broadly interpreted, is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years.
It may be a change in average weather conditions, or in the distribution of weather around the average conditions such as more or fewer extreme weather events. Climate change is caused by factors that include oceanic processes such as oceanic circulation , biotic processes e.
The latter effect is currently causing global warming, and "climate change" is often used to describe human-specific impacts. From ancient times, people suspected that the climate of a region could change over the course of centuries. For example, Theophrastus , a pupil of Aristotle , told how the draining of marshes had made a particular locality more susceptible to freezing, and speculated that lands became warmer when the clearing of forests exposed them to sunlight.
Renaissance and later scholars saw that deforestation , irrigation , and grazing had altered the lands around the Mediterranean since ancient times; they thought it plausible that these human interventions had affected the local weather. The 18th and 19th century conversion of Eastern North America from forest to croplands brought obvious change within a human lifetime.
From the early 19th century, many believed the transformation was altering the region's climate—probably for the better. When farmers in America, dubbed "sodbusters", took over the Great Plains , they held that " rain follows the plow.
European academics, convinced of the superiority of their own civilisation, said that the Orientals of the Ancient Near East had heedlessly converted their once lush lands into impoverished deserts. Meanwhile, national weather agencies had begun to compile masses of reliable observations of temperature, rainfall, and the like. When these figures were analyzed, they showed many rises and dips, but no steady long-term change.
By the end of the 19th century, scientific opinion had turned decisively against any belief in a human influence on climate. And whatever the regional effects, few imagined that humans could affect the climate of the planet as a whole. From the midth century, naturalists attempted to reconcile mechanical philosophy with theology, initially within a Biblical timescale. By the late 18th century, there was increasing acceptance of prehistoric epochs. Geologists found evidence of a succession of geological ages with changes in climate.
There were various competing theories about these changes; Buffon proposed that the Earth had begun as an incandescent globe and was very gradually cooling. James Hutton , whose ideas of cyclic change over huge periods of time were later dubbed uniformitarianism , was among those who found signs of past glacial activity in places too warm for glaciers in modern times.
In Jean-Pierre Perraudin described for the first time how glaciers might be responsible for the giant boulders seen in alpine valleys. As he hiked in the Val de Bagnes , he noticed giant granite rocks that were scattered around the narrow valley. He knew that it would take an exceptional force to move such large rocks. He also noticed how glaciers left stripes on the land, and concluded that it was the ice that had carried the boulders down into the valleys.
His idea was initially met with disbelief. Jean de Charpentier wrote, "I found his hypothesis so extraordinary and even so extravagant that I considered it as not worth examining or even considering.
Venetz convinced Charpentier, who in turn convinced the influential scientist Louis Agassiz that the glacial theory had merit. Agassiz developed a theory of what he termed " Ice Age "—when glaciers covered Europe and much of North America. In Agassiz was the first to scientifically propose that the Earth had been subject to a past ice age. This was strongly opposed by Charles Lyell 's version of Hutton's uniformitarianism, and was gradually abandoned by Buckland and other catastrophist geologists.
A field trip to the Alps with Agassiz in October convinced Buckland that features in Britain had been caused by glaciation, and both he and Lyell strongly supported the ice age theory which became widely accepted by the s.
Before the concept of ice ages was proposed, Joseph Fourier in reasoned on the basis of physics that Earth's atmosphere kept the planet warmer than would be the case in a vacuum.
Fourier recognized that the atmosphere transmitted visible light waves efficiently to the earth's surface. The earth then absorbed visible light and emitted infrared radiation in response, but the atmosphere did not transmit infrared efficiently, which therefore increased surface temperatures. He also suspected that human activities could influence climate, although he focused primarily on land use changes.
In an paper Fourier stated, "The establishment and progress of human societies, the action of natural forces, can notably change, and in vast regions, the state of the surface, the distribution of water and the great movements of the air. Such effects are able to make to vary, in the course of many centuries, the average degree of heat; because the analytic expressions contain coefficients relating to the state of the surface and which greatly influence the temperature.
The physicist Claude Pouillet proposed in that water vapour and carbon dioxide might trap infrared and warm the atmosphere, but there was still no experimental evidence of these gases absorbing heat from thermal radiation.
The warming effect of electromagnetic radiation on different gases was examined in by Eunice Newton Foote , who described her experiments using glass tubes exposed to sunlight. The warming effect of the sun was greater for compressed air than for an evacuated tube, and greater for moist air than dry air. Joseph Henry at the American Association for the Advancement of Science meeting in August and described as a brief note written by then journalist David Ames Wells ; her paper was published later that year in the American Journal of Science and Arts.
John Tyndall took Fourier's work one step further in when he investigated the absorption of infrared radiation in different gases. He found that water vapor, hydrocarbons like methane CH 4 , and carbon dioxide CO 2 strongly block the radiation. Some scientists suggested that ice ages and other great climate changes were due to changes in the amount of gases emitted in volcanism. But that was only one of many possible causes. Another obvious possibility was solar variation.
Shifts in ocean currents also might explain many climate changes. For changes over millions of years, the raising and lowering of mountain ranges would change patterns of both winds and ocean currents.
Or perhaps the climate of a continent had not changed at all, but it had grown warmer or cooler because of polar wander the North Pole shifting to where the Equator had been or the like. There were dozens of theories. For example, in the midth century, James Croll published calculations of how the gravitational pulls of the Sun, Moon, and planets subtly affect the Earth's motion and orientation. The inclination of the Earth's axis and the shape of its orbit around the Sun oscillate gently in cycles lasting tens of thousands of years.
During some periods the Northern Hemisphere would get slightly less sunlight during the winter than it would get during other centuries.
Snow would accumulate, reflecting sunlight and leading to a self-sustaining ice age. In , Peter Kropotkin wrote about his observations that since the Industrial Revolution , Siberian glaciers were melting. Very  had attempted to determine the surface temperature of the Moon by measuring infrared radiation leaving the Moon and reaching the Earth.
This result was unsurprising given that scientists had known about infrared radiation absorption for decades. In Svante Arrhenius used Langley's observations of increased infrared absorption where Moon rays pass through the atmosphere at a low angle, encountering more carbon dioxide CO 2 , to estimate an atmospheric cooling effect from a future decrease of CO 2.
He realized that the cooler atmosphere would hold less water vapor another greenhouse gas and calculated the additional cooling effect. He also realized the cooling would increase snow and ice cover at high latitudes, making the planet reflect more sunlight and thus further cool down, as James Croll had hypothesized. Overall Arrhenius calculated that cutting CO 2 in half would suffice to produce an ice age.
He further calculated that a doubling of atmospheric CO 2 would give a total warming of 5—6 degrees Celsius. However, because of the relatively low rate of CO 2 production in , Arrhenius thought the warming would take thousands of years, and he expected it would be beneficial to humanity. In Thomas Chrowder Chamberlin developed at length the idea that changes in climate could result from changes in the concentration of atmospheric carbon dioxide. Previous advocacy of an atmospheric hypothesis, — The general doctrine that the glacial periods may have been due to a change in the atmospheric content of carbon dioxide is not new.
It was urged by Tyndall a half century ago and has been urged by others since. Recently it has been very effectively advocated by Dr. Arrhenius, who has taken a great step in advance of his predecessors in reducing his conclusions to definite quantitative terms deduced from observational data.
It follows that the effect of the carbon dioxide and water vapor is to blanket the earth with a thermally absorbent envelope. In the case of the outgoing rays, which are absorbed in much larger proportions than the incoming rays because they are more largely long-wave rays, the tables of Arrhenius show that the absorption is augmented by increase of carbonic acid in greater proportions in high latitudes than in low; for example, the increase of temperature for three times the present content of carbonic acid is It now becomes necessary to assign agencies capable of removing carbon dioxide from the atmosphere at a rate sufficiently above the normal rate of supply, at certain times, to produce glaciation; and on the other hand, capable of restoring it to the atmosphere at certain other times in sufficient amounts to produce mild climates.
When the temperature is rising after a glacial episode, dissociation is promoted, and the ocean gives forth its carbon dioxide at an increased rate, and thereby assists in accelerating the amelioration of climate. A study of the life of the geological periods seems to indicate that there were very notable fluctuations in the total mass of living matter. To be sure there was a reciprocal relation between the life of the land and that of the sea, so that when the latter was extended upon the continental platforms and greatly augmented, the former was contracted, but notwithstanding this it seems clear that the sum of life activity fluctuated notably during the ages.
It is believed that on the whole it was greatest at the periods of sea extension and mild climates, and least at the times of disruption and climatic intensification. This factor then acted antithetically to the carbonic acid freeing previously noted, and, so far as it went, tended to offset its effects. In periods of sea extension and of land reduction base-level periods in particular , the habitat of shallow water lime-secreting life is concurrently extended, giving to the agencies that set carbon dioxide free accelerated activity, which is further aided by the consequent rising temperature which reduces the absorptive power of the ocean and increases dissociation.
At the same time, the area of the land being diminished, a low consumption of carbon dioxide both in original decomposition of the silicates and in the solution of the limestones and dolomites obtains. Thus the reciprocating agencies again conjoin, but now to increase the carbon dioxide of the air. These are the great and essential factors.
They are modified by several subordinate agencies already mentioned, but the quantitative effect of these is thought to be quite insufficient to prevent very notable fluctuations in the atmospheric constitution. As a result, it is postulated that geological history has been accentuated by an alternation of climatic episodes embracing, on the one hand, periods of mild, equable, moist climate nearly uniform for the whole globe; and on the other, periods when there were extremes of aridity and precipitation, and of heat and cold; these last denoted by deposits of salt and gypsum, of subaerial conglomerates, of red sandstones and shales, of arkose deposits, and occasionally by glaciation in low latitudes.
The term " greenhouse effect " for this warming was introduced by John Henry Poynting in , in a commentary discussing the effect of the atmosphere on the temperature of the Earth and Mars.
Arrhenius's calculations were disputed and subsumed into a larger debate over whether atmospheric changes had caused the ice ages. Experimental attempts to measure infrared absorption in the laboratory seemed to show little differences resulted from increasing CO 2 levels, and also found significant overlap between absorption by CO 2 and absorption by water vapor, all of which suggested that increasing carbon dioxide emissions would have little climatic effect.
These early experiments were later found to be insufficiently accurate, given the instrumentation of the time. Many scientists also thought that the oceans would quickly absorb any excess carbon dioxide. Other theories of the causes of climate change fared no better. The principal advances were in observational paleoclimatology , as scientists in various fields of geology worked out methods to reveal ancient climates.
The history of the scientific discovery of climate change began in the early 19th century when ice ages and other natural changes in paleoclimate were first suspected and the natural greenhouse effect was first identified. In the late 19th century, scientists first argued that human emissions of greenhouse gases could change the climate. Many other theories of climate change were advanced, involving forces from volcanism to solar variation. In the s, the evidence for the warming effect of carbon dioxide gas became increasingly convincing. Some scientists also pointed out that human activities that generated atmospheric aerosols e.
Natural gas is a fossil fuel, though the global warming emissions from its combustion are much lower than those from coal or oil. Natural gas emits 50 to 60 percent less carbon dioxide CO2 when combusted in a new, efficient natural gas power plant compared with emissions from a typical new coal plant [ 1 ]. The drilling and extraction of natural gas from wells and its transportation in pipelines results in the leakage of methane, primary component of natural gas that is 34 times stronger than CO2 at trapping heat over a year period and 86 times stronger over 20 years [ 3 ]. Whether natural gas has lower life cycle greenhouse gas emissions than coal and oil depends on the assumed leakage rate, the global warming potential of methane over different time frames, the energy conversion efficiency, and other factors [ 5 ]. One recent study found that methane losses must be kept below 3. And if burning natural gas in vehicles is to deliver even marginal benefits, methane losses must be kept below 1 percent and 1. Technologies are available to reduce much of the leaking methane, but deploying such technology would require new policies and investments [ 7 ].
His timely book,. Air Pollution and Global Warming: History, Science, and Solutions (second edition), is an encouraging overview of environmental issues linked.
Air Pollution and Global Warming: History, Science, and Solutions
In the following viewpoint, Canadell argues that recent efforts to improve energy efficiency and increase the use of clean energy have contributed to a stalling in fossil fuel emissions. However, Canadell contends that governments will need to increase their efforts to meet the climate goals established in the Paris Agreement. He compares the successes and shortcomings of China, the United States, India, Australia, and the European Union in reducing emissions.
Jacobson Cambridge University Press, Cambridge, This book provides an introduction to the history, science, and solutions of local and global air pollution and global warming. It first introduces the history of discovery of chemicals in the air, then discusses the historic evolution of the Earth's atmosphere and the structure and composition of the present-day atmosphere. Subsequently, it examines historical, scienctific, and regulatory aspects of five major air-related topics: urban outdoor air pollution, indoor air pollution, acid deposition, global stratospheric and Antarctic ozone reduction, and global warming.
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- Он замолчал, словно подбирая нужные слова. - Этот шифр взломать невозможно. Сьюзан посмотрела на него и едва не рассмеялась.
О юристах, фанатичных борцах за гражданские права, о Фонде электронных границ - они все приняли в этом участие, но дело в другом. Дело в людях. Они потеряли веру. Они стали параноиками.
Беккер убрал блокнот и ручку.