Industrial greenhouse emissions

Since the Industrial Revolution, increased amounts of anthropogenic industrial GHG emissions from factories and power plants have combined with emissions from other sources to raise the global temperature and change the climate. Modern technology has accelerated the global warming process with the production of new industrial GHGs.

Background

Industrial greenhouse gases (GHGs) are anthropogenic gaseous constituents of the atmosphere produced by human industrial processes that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared radiation, emitted by the Earth’s surface, the atmosphere, and by clouds. This phenomenon causes the greenhouse effect, which contributes to global warming. The concentrations of carbon dioxide (CO₂) among such emissions are now more than one-third higher than they were before the Industrial Revolution. The Earth is artificially made even warmer by hydrofluorocarbons (HFCs) from industrial activities that trap extra heat from the sun, causing changes in weather patterns around the globe.

The Sources and Levels of Industrial Greenhouse Emissions

CO₂, the most abundant GHG, is emitted from products and by-products of manufacturing sites, and from burning fossil fuels at large industrial facilities. Natural gas, coal, and oil are the three types of polluting power plants, and they produce 40 percent of CO₂ in the United States, coal being the biggest contributor. Brown coal produces more CO₂ than black coal. In the United States, industrial CO₂ emissions, resulting both directly from the combustion of fossil fuels and indirectly from the generation of electricity that is consumed by industry, accounted for 28 percent of CO₂ from fossil fuel combustion in 2006.

Industrial processes are among the six major sources of pollution in the United States and are responsible for over 60 percent of Canada’s total emissions. In the United States, energy-related activities account for over three-quarters of anthropogenic GHG emissions, more than half of which comes from power plants and industrial processes. When emissions from electricity were distributed among various sectors, industry accounted for the largest share of U.S. GHG emissions (29 percent) in 2006. Overall, emission sources from industrial processes accounted for 4.5 percent of U.S. GHG emissions in 2006.

The six major industrial GHGs are CO₂, methane, nitrous oxide, hydrofluorocarbons, Perfluorocarbons (PFCs), and sulfur hexafluoride (SF₆). The major industrial greenhouse gases are released from manufacturing and production processes related to iron ore pelletizing, lime, iron and steel, titanium, pulp and paper, aluminum and alumina, cement, petroleum refining, chemicals and fertilizers, electricity (produced with oil, coal, and gas), natural gas pipelines, potash, base metal smelters, silicon carbide, nitric acid, ammonia, urea, limestone and dolomite use (such as flux stone, flue gas desulfurization, and glass manufacturing), soda ash, ferroalloy, zinc, phosphoric acid, titanium dioxide production, lead, coal mining, wastewater treatment, stationary combustion, composting, manure management, semiconductors, magnesium, and adipic acid.

At present, electric power generation is the largest contributor to industrial GHG emissions. Industrial methane comes from petroleum systems and coal mining. Unintentional fugitive industrial methane emissions come from equipment leaks, natural gas distribution, and storage facilities. Nitrous oxide is generated during the production of nitric acid and adipic acid. The manufacture of liquid crystal display (LCD) screens releases nitrogen trifluoride. Reports in 2008 indicated a rise in airborne levels of nitrogen trifluoride from flat-panel screen technology (manufacture of LCD screens).

Industrial activities also produce several classes of greenhouse halogenated substances that contain fluorine, chlorine, or bromine, such as potent greenhouse HFCs, PFCs, and SF₆ gases.Sulfur hexafluoride is the most potent GHG the IPCC has evaluated. Chlorofluorocarbons, or CFCs, are wholly human-made, new to the atmosphere, and widely used in aerosols, foam manufacture, air conditioning, and refrigeration. Other industrial sources include HCFC-22 production, semiconductor manufacturing, aluminum production, and magnesium production and processing.

Capacity of Industrial Emissions to Affect Climate Change

Industrial emissions form a significant percentage of anthropogenic sources of GHGs that are blanketing the Earth and increasing the average global air temperature near the Earth’s surface. Industrial processes can chemically transform raw materials, which often release waste gases such as CO₂, CH₄, and N₂O, gases that can influence the atmospheric lifetimes of other gases. These emissions can affect atmospheric processes that alter the radiative balance of the Earth, such as cloud formation or albedo. The IPCC reported in 2007 that methane is twenty times as effective as CO₂ at trapping heat in the atmosphere, and its concentration in the atmosphere has increased by 148 percent over the last 250 years.

Nitrous oxide is over three hundred times more powerful than CO₂. Nitrogen trifluoride is thousands of times stronger at trapping atmospheric heat than CO₂. Human industrial activity has produced very potent GHGs such as hydrofluorocarbons that trap more heat from the Sun than CO₂ and other GHGs, making the Earth artificially warmer. As a result, extreme weather events will become more frequent, more widespread, and more intense in the times ahead. In addition to having high global warming potentials, SF₆ and PFCs have extremely long atmospheric lifetimes, resulting in their irreversible accumulation in the atmosphere once emitted.

How Industrial Greenhouse Emissions Affect Climate and Global Events

Industrial greenhouse emissions play a major role in the gaseous blanketing effects that create higher temperatures around the Earth. Chlorofluorocarbons emitted from factories destroy the protective ozone layer, causing more intense solar radiation to bombard the Earth. Increasing global temperature is expected to cause sea levels to rise, increase the intensity of extreme weather events, and create significant changes to the amount and pattern of precipitation, likely leading to an expanse of tropical areas, loss of biodiversity, and increased pace of desertification.

The effects of climate change have serious implications for the economy and environment of nations. Winters are becoming milder, and summers are becoming hotter. Snowpacks are shrinking, and unseasonably warm temperatures are leading to rapid spring melts, depleting the supply of summer water for agriculture and stream flows for wildlife. Storms and forest fires are becoming more severe while the risk of coastal flooding is increasing. These climatic changes will potentially affect native ecosystems, industries, infrastructure, health, biosecurity, and the economy.

Industrial smog emissions provoke responses of the atmosphere that cause health hazards, and affect agricultural as well as drinking water supplies. Other expected effects include modifications of trade routes, glacier retreat and disappearance, mass species extinctions, increases in the ranges of disease vectors, changes in quantity and quality of agricultural yields, and impacts on land use due to significant alterations in temperature and rainfall patterns. The health of livestock and other animals will be affected, as pests, pathogens, and diseases become modified or multiply. Land erosion and impoverishment will abound, with increase in soil infertility and proliferation of weeds. All these factors will have poverty impacts on people and jeopardize the global economy.

Direct and Indirect Industrial Emission Impacts on the Atmosphere and Environment

Direct radiative effects of industrial GHGs occur when the gases themselves absorb radiation and warm the Earth. Strong industrial greenhouse emissions such as CFCs directly contribute significantly to the depletion of the protective ozone layer around the Earth.

The IPCC reported in 2007 that from the preindustrial era (ending about 1750) to 2005, concentrations of CO₂, CH₄, and N₂O have increased globally by 36, 148, and 18 percent, respectively. Their emissions from industrial sources directly pollute groundwater after rainfall has washed the pollutants into the soil. Toxins from the pollutants directly affect the health, growth, and reproduction of plants and animals.

Indirect atmospheric modification occurs when chemical transformations of the substances emitted from industrial processes produce other GHGs. Industries contain by-product or fugitive emissions of GHGs from industrial processes not directly related to energy activities. Industrial gases can also indirectly influence the atmospheric lifetimes of other gases. There are several gases that do not have a direct global warming effect but indirectly affect terrestrial and solar radiation absorption by causing some GHGs to persist longer in the atmosphere, and influencing the formation or destruction of other GHGs, including tropospheric and stratospheric ozone depletion. These gases include carbon monoxide (CO), oxides of nitrogen (NOx), and non-CH₄volatile organic compounds (NMVOCs).

Context

Today, Earth is hotter than it has been in two thousand years. The global temperature will rise higher, to destructive levels, than at any time in the past two million years if industrial emissions are not reduced. The IPCC predicts a further rise of 1.1° to 6.4 ° Celsius in the average global surface temperature. According to the Science Daily of September 17, 2008, the Earth will warm about 2.4° Celsius above preindustrial levels even under extremely conservative GHG emission conditions and under the assumption that efforts to clean up pollution continue to be successful. Although most studies focus on the period up to 2100, warming and sea-level rise are expected to continue for more than a thousand years even if GHG levels are stabilized. The delay in reaching equilibrium is due to the large heat capacity of the oceans.

As a result of the 1987 Montreal Protocol to curb CFCs, the IPCC reported in 2007 that the production of ozone-depleting substances (ODS) is being phased out, as CFCs and HCFCs are replaced by ODS substitutes such as HFCs and PFCs. Unfortunately, the substitutes, while being relatively harmless to the ozone layer, are equally potent GHGs, and at present their phase-out dates are not due for another 20 to 30 years.

Technological advancement and innovation are critical to achieving significant, long-term reductions in industrial GHG emissions. Investments in biofuels and alternative energy sources would promote clean electricity. Cement producers could use waste material from other industries in place of emission-intensive clinker. Some industries have installed new technology to cut emissions, and use filters that improve the quality of the air released into the atmosphere.

Key Concepts

• albedo: the fraction of incident light reflected from a body such as Earth
• anthropogenic: derived from human sources or activities
• biodiversity: the variety of organisms at a particular geographic location
• biosecurity: measures required or taken to protect organisms from risk or danger
• fossil fuels: fuels formed by the chemical alteration of plant and animal matter under geologic pressure over long periods, including coal, oil, and natural gas
• greenhouse gases (GHGs): gaseous constituents of the atmosphere, both natural and anthropogenic, that contribute to the greenhouse effect
• industrial: related to large-scale manufacturing or energy production
• Intergovernmental Panel on Climate Change (IPCC): a scientific intergovernmental body set up by the World Meteorological Organization (WMO) and by the United Nations Environment Programme (UNEP)
• ozone layer: a region of the upper atmosphere with high concentration of ozone (a gaseous form of oxygen) that protects the Earth by absorbing solar ultraviolet radiation

Bibliography

Clarke, A. G. Industrial Air Pollution Monitoring: Gaseous and Particulate Emissions. Environment Management Series 8. New York: Springer, 1997. Provides details of the types, effects, and emission rates of industrial pollutants.

Friedrich, R., and S. Reis, eds. Emissions of Air Pollutants: Measurements, Calculations, and Uncertainties. New York: Springer, 2004. Provides information intended to guide efforts to reduce and mitigate air pollution and to design experiments related to specific pollution sources.

Hardy, John T. Climate Change: Causes, Effects, and Solutions. New York: John Wiley, 2003. Emphasizes and explains potential global effects of anthropogenic climate change and provides scientific findings, case studies, and discussions of the broader issues of the ecological, economic, and human effects of such change.

Quigley, John T., Howard E. Hesketh, and Frank L. Cross, Jr. Emission Control from Industrial Boilers. Lancaster, Pa.: Technomic, 1995. Provides in-depth treatment of industrial production related to the Clean Air Act, boiler systems, combustion fundamentals, scrubbers, filters, disposal of residuals, and emission monitoring.

Reay, Dave. Climate Change Begins at Home: Life on the Two-Way Street of Global Warming. New York: Palgrave Macmillan, 2006. Analyzes case studies, emissions trends, lifestyle comparisons, and calculations describing climate change as a great twenty-first century human threat.