Greenhouse Effect and How It Works
Green house effect is the natural process through which the atmosphere traps some of the sun rays to warm the earth sufficiently to support life. Once the solar energy supplied by the sun reaches the earth's surface, it follows a complex path. Some of the solar energy is reflected back to the atmosphere, while the rest of the energy is absorbed by the earth’s land and ocean (Berner, 2012). The absorbed land warms the earth, and then is radiated back in the form of infrared rays. The infrared energy radiates its molecules in different directions including back to the earth, while some remain in the atmosphere warming the earth. An increase in the greenhouse effect causes global warming. When the sunrays hit, up to 70 percent of the energy stays on the surface of the earth.
The Main Greenhouse Gasses
Carbon dioxide is the major greenhouse gas. It is emitted naturally from plants and animals. It is also emitted through human activities such as combustion of substances. Burning of fossil fuels is the chief source for the increase in carbon dioxide emissions. The earth’s vegetation, oceans, and soils absorb the emitted carbon dioxide. Burning of fossil fuel uses oxygen and emits carbon dioxide. Because of the heavy combustion of fossil fuels, there is a constant increase in the level of carbon dioxide in the atmosphere. The rest of the emissions stay in the atmosphere for long periods. Carbon dioxide does not absorb the energy from the sun but absorbs energy and heat released from the earth. Carbon dioxide prevents the reflection of the sun’s rays back to the sun.
Methane is the second most rampant greenhouse gas, which results from human activities. Globally, approximately 60 percent of the total methane emissions come from human activities. In 2011, methane accounts for 9 percent of all the greenhouse gas emissions from human activities in the United States. In addition, methane is also emitted from natural sources such as wetlands, and the leakage of natural gas systems (Howarth et al., 2011). Methane, like other atmospheric gases, does not react to the changes in temperature and air pressure. Therefore, they are not extractable easily from the atmosphere, unlike water that condenses to rain or snow. They have a long-term atmospheric lifetime, allowing them to have a lasting effect on universal global warming and climate change.
Nitrous oxide is a powerful green house gas that has global warming potential of approximately 300 times more than carbondioxide. The major sources of this gas come from the use of fertilizers, combustion of fossil fuel, combustion of biomass, and the production of nitric acid. Natural emissions of nitric acid occur from the bacteria breaking down nitrogen in the soils and oceans. The nitrous oxide is mainly removed from the atmosphere through the destruction of stratosphere by ultra violet radiations associated with chemical reactions.
Hydroflurocarbons are used in refrigerants, aerosols, propellants, and several other solvents. The major emission is their use as refrigerants, in air conditioning systems in buildings and vehicles. These gasses have a long atmospheric lifetime through leakage, servicing, and disposal of equipments. Perflourocarbons are by products compounds produced from various industrial processes associated with the production of aluminum products and semiconductors. The perflorocarbons also have a long atmospheric lifetime.
The Present Level of Atmospheric Carbon Dioxide for August 2013
The present level of carbon dioxide is 394.16 parts per million, which is higher compared to the 391.81 parts per million, recorded at the same time one year ago. This level of carbon dioxide has exceeded the upper safety limit of 350 parts per million. Therefore, the concentration of carbon dioxide is increasing at an accelerating rate, and the current data are a continuation of the long-standing trend. Carbon dioxide levels are constantly high since 1988.
Reason for the Rise in Carbon Dioxide Concentration Since 1860
Carbon dioxide captures the largest portion of human emissions. Increase in human activities has caused a large increase in atmospheric greenhouse gas since the pre-industrial period. Increase in fossil fuel burning, deforestation, and other human influences are the major causes of the increase since the pre industrial era (Doney et al., 2009). Burning coal, oil, and natural gas releases about 6 billion tons of carbon annually. Furthermore, burning and logging of forests contributes another one to two billion tons annually by reducing the storage of carbon dioxide in the trees. Over this period, the agricultural and industrial practices have been on the increase. Carbon dioxide like other greenhouse gases has a longer atmospheric lifetime ranging from centuries.
Environmental Damages of Increase in Carbon Dioxide Levels
The current environmental impacts include biodiversity loss, exemplified by the increased risk of extinction and disappearance of habitat. This is due to changing ecosystems and acidification of the oceans. There is also a decline in the numbers of polar bears. The arctic sea is the feeding habitat for the polar bears, therefore, the disappearance of the sea ice increases bear mortality (Doney et al., 2009). The increase in the level of carbon dioxide has led to acidification of the oceans, polluting it. The acidified oceans can lead to coral bleaching. Coral reefs are sensitive to changes in water temperature, as the increase in heat leads to loss of algae that nourish them. The potential future effects of global warming due to rise in carbon dioxide levels include an increase in the frequency of wildfires, longer periods of drought, and the increase in number, duration and intensity of tropical storms.
Mitigating the Effects of Increased Carbon Dioxide Emissions
Most of the scientists agree on the need to adopt mitigation strategies. Broad scientific communities predict that the climate change will worsen when the concentration of greenhouse gases in the atmosphere rises above 450 parts per million. Understanding the future weather is essential. With nuclear applications, it is possible to understand the drivers of a climate change. Through reconstruction, scientists can estimate the future developments. The nuclear isotopes are significant in mapping the increase in ocean temperature as well as the sitting currents. Furthermore, the emission of greenhouse gasses can be reduced through appropriate techniques. For example, power generation is the major source of all the greenhouse emissions. Scientists estimate that generation of electricity will remain to be the fastest source for the next two decades. The use of nuclear energy to supply electricity reduces the annual global carbon dioxide burden. Based on the scientific data, continued emission of greenhouse gases will lead to further climate changes. The future impacts include warmer atmosphere, more acidic oceans, increased sea levels and the constant changes in precipitation patterns.