Saturday, March 13, 2010

Greenhouse Gas & Air Quality Emissions

Emissions are gases and particles released into the air as byproducts of a natural or man-made process. One of these processes is the burning of fuels to create electricity and other forms of energy. The emissions from burning fossil fuels contribute significantly to global warming and poor air quality. A small set of emissions are responsible for the majority of human impacts on climate change and health. These gases and particulates come from a variety of sources and can be categorized as greenhouse gas emissions and air quality emissions that affect climate change.

Worldwide emission levels from human activity have increased significantly over the past 200 years as industrial activity, electricity infrastructure, and transportation have developed. As broader understanding of the impacts of these emissions has increased, regulation and new development practices have been implemented to reduce the rate of emissions in many countries. However, high levels of these emissions are still being produced each year. Greenhouse gas emissions come from four main sources: the burning of fossil fuels to make electricity; industrial, commercial and residential burning of fossil fuels for heat and the use of other emission-producing processes; the burning of fossil fuels to power transportation; and the emissions produced through agriculture and other activities.

There are different types of emissions that contribute to poor air quality and climate change. Carbon Dioxide (CO2) is the most common. Methane is another naturally occurring gas. Human activities that produce methane include fossil fuel production, decay in landfills, and the digestive processes of farm animals such as cattle. Halocarbons are entirely man-made chemicals. Their most common use is in refrigeration and air conditioning technologies but they are also used heavily in the electric system infrastructure. When released into the atmosphere as gases, they can significantly impact global climate patterns. Other gases like carbon monoxide and nitrogen oxides impact climate change indirectly and have more direct effects on health when they are released into the lower atmosphere. Carbon monoxide is an odorless, colorless and toxic gas. Unvented kerosene and gas space heaters, leaking chimneys and furnaces, wood and gas stoves, and fireplaces, gas stoves, generators and other gasoline powered devices, automobile exhaust from attached garages; and tobacco smoke are sources of carbon dioxide. It is particularly dangerous when released in closed places like garages and kills close to 500 people each year in the US. Nitrogen oxides, or NOx, is the generic term for a group of highly reactive gases. The primary manmade sources of NOx are motor vehicles, electric utilities, and other industrial, commercial, and residential sources that burn fuels. NOx can also be formed naturally. Sulfur dioxide (SO2) is a gas that is prevalent in crude oil, coal, and ore that contains common metals like aluminum, copper, zinc, lead and iron. The majority of SO2 released into the atmosphere comes from coal burning power plants. Other sources of this pollutant are petroleum refineries, cement manufacturing, and metal processing facilities.

Volatile Organic Compounds (VOCs) include a variety of chemicals, some of which may have short- and long-term negative health effects. Many Volatile Organic Compounds are human-made chemicals that are used and produced in the manufacture of paints, pharmaceuticals, cleaning fluids and refrigerants. VOCs have been found to be a major contributing factor to ozone, a common air pollutant which is a public health hazard. VOCs can be present in wells and public drinking water. They can enter ground water from a variety of sources. Benzene, for example, may enter ground water from gasoline or oil spills on the ground surface or from leaking underground fuel tanks. Other examples of commonly detected VOCs are ethylene chloride, (an industrial solvent), tetrachloroethylene (perchloroethylene), used in the dry-cleaning industry and trichloroethylene, used in septic system cleaners.

Particulates may be the air pollutant that most commonly affects human health. Particulates commonly referred to as particulate matter or fine particles, are tiny particles of solid or liquid suspended in a gas. There are both natural and human sources of atmospheric particulates. The main natural sources are forest fires, dust, and volcanoes. The biggest human sources of particles are mainly from the use of automobiles and power plants.

Ozone is a gas that occurs both in the Earth's upper atmosphere and at ground level. The stratosphere or "good" ozone layer extends upward from about 6 to 30 miles and protects life on Earth from the sun's harmful ultraviolet (UV) rays. This natural shield has been gradually depleted by man-made chemicals like chlorofluorocarbons (CFCs). A depleted ozone shield allows more UV radiation to reach the ground, leading to more cases of skin cancer, and other health and environmental problems. Ground-level or "bad" ozone is a pollutant that is a significant health risk, especially for children with asthma. It also damages crops, trees and other vegetation. It is a main ingredient of urban smog. High concentrations of ozone, created by high concentrations of pollution and daylight UV rays at the earth's surface, can harm the human respiratory system.

As you can see we are putting a toxic mess into our atmosphere, soil and water systems. This accounts for many health issues and premature deaths in society. Our planet can no longer support the rate that humans place emissions into our atmosphere. We need to find solutions to this issue. One solution is clean energy. Clean energy typically produces no emissions, which is one of its most significant benefits. We need to make urgent choices to help save the planet for future generations.

Clean energy typically produces no emissions, which is one of its most significant benefits.

CO2 & Global Warming

Carbon dioxide (CO2) is one of the most common greenhouse gases in the atmosphere and is regulated through the natural carbon cycle, where carbon dioxide is emitted into the air and reabsorbed by vegetation and water. This cycle is upset by the emission of additional carbon dioxide from human activities. Because natural cycles cannot absorb these additional emissions, a large portion of carbon dioxide remains in the atmosphere and increases climate change. Carbon dioxide is produced by all animals, plants, fungi and microorganisms during respiration and is used by plants during photosynthesis Carbon dioxide is not a bad thing, in fact it is essential for life. The problem is the amount that is put into our atmosphere. The primary human source of carbon dioxide is the burning of fossil fuels for electricity, heat, and transportation. Small changes as a result of human activities can have a large impact on this delicate balance.

The rate at which humans are pumping carbon dioxide into the atmosphere has more than doubled since the 1990s, according to Australian research in the latest report warning about the high rate of emissions accumulating in the atmosphere. The United States is the one of the largest emitters of carbon dioxide emissions. Also in the top five countries are China and India. Of the carbon dioxide emissions arising from fossil fuel combustion around 40% is a result of electricity generation, with coal-fired generation being the leading sector. Other stationary sources include industrial, emissions resulting from oil extraction, refinement and transportation, and domestic and commercial fossil fuel use. Globally, transport-related emissions of carbon dioxide are growing rapidly. Road transport dominates these emissions, though off-road, air and marine transport emissions are also significant. The use of petroleum as a fossil fuel for transportation dominates carbon dioxide emissions from this source. About two-thirds of this is from gasoline consumption by motor vehicles and the remainder coming from diesel and jet fuel use in trucks and aircraft... Carbon dioxide is probably the most significant of the greenhouse gases as it accounts for the largest proportion of the 'trace gases' and is currently responsible for 60% of the 'enhanced greenhouse effect'. Carbon dioxide stays in the atmosphere for approximately 100 years. Small changes as a result of human activities can have a large impact on this delicate balance.

We can reverse the trend of rising carbon dioxide emissions into the atmosphere. Driving more fuel efficient vehicles would be a huge step. With the rise in the price of oil we may be forced into this measure. In our homes we can change to more efficient energy sources along with "reuse, reduce and recycle". We can also make companies more environmentally accountable by patronizing companies that are environmentally friendly instead of doing business with environmentally irresponsible ones...

No comments:

Post a Comment

google search

Custom Search