Climate Change, the Arctic Thaw and Climate Change Mitigation and Adaptation

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nPart A: Greenhouse Gases and Earths Energy Budget

nQuestion 1

n Greenhouse gases are both natural and synthetic gases in the atmosphere that allow the short energy waves from the sun to pass through the earths surface without any form of hindrance. The primary sources of greenhouse gases are artificial such as burning of fossil fuels and other industrial processes (Bessou, Ferchaud, Gabrielle & Mary, 2011). The natural sources are respiration of living organisms. Greenhouse gases have a global warming potential as they act as positive radiative forcings (Andrews, Gregory, Webb & Taylor, 2012). They are transparent to incoming solar energy but are opaque to infrared energy from the earth which is of longer wavelength than that of incoming solar energy (Bessou, Ferchaud, Gabrielle & Mary, 2011). They, therefore, cause an imbalance in the earths energy budget because the incoming energy on the lands surface is higher than the outgoing energy (Rosenfeld, Sherwood, Wood & Donner, 2014). Carbon dioxide is the most powerful radiative forcing among the other greenhouse gases because it absorbs infrared energy with wavelength spectrum that other gases cannot absorb.

nQuestion 2

nWith the increased industrial revolution, several human activities have affected the biogeochemical reservoirs and the pathways of carbon which has, in turn, led to climatic changes. Coal and fossil fuels are reservoirs for the carbon element. Industrialisation has also contributed to the increased mining and burning of fossil fuels. Burning carbon pools leads to greater accumulation of carbon dioxide in the atmosphere (Bessou, Ferchaud, Gabrielle & Mary, 2011). Human beings have cleared most of the vegetation that would act as carbon sinks. These human activities have disrupted the pathways of carbon through the shift of carbon from lithosphere to the atmosphere. This has, in turn, led to global warming as carbon dioxide is a very powerful positive radiative. The impact of human activities on global warming due to disruption of carbon pathways is evident from the trend of gradual changes in climatic conditions on earth since the rise of industrialisation.

nQuestion 3

nApart from greenhouse gases, there exist other forcings that affect the earths energy budget. The first forcing is changes in the brightness of the sun. When the intensity of the sun increases, the solar energy reflected to the earths surface increases, which leads to positive radiative forcing (Church et al., 2011). Milankovitch cycles are another climate forcings. These cycles relate to the rotation of the earth. When the earths land mass faces the sun, more heat is absorbed on the earths surface which leads to positive radiative forcing because the land absorbs more heat energy than the water mass (Church et al., 2011). After a volcanic eruption, highly reflective substances are released to the upper atmosphere, which reflects solar radiation to space. This leads to cooling of the earths surface. A volcanic eruption is, therefore, a negative radiative forcing (Rosenfeld, Sherwood, Wood & Donner, 2014). Aerosols can be produced from combustion of fossil fuels. Just as in the aerosols produced during volcanic activities, aerosols are negative radiative forcings (Rosenfeld, Sherwood, Wood & Donner, 2014). Deforestation is a positive radiative forcing as it leads to the increase of carbon dioxide in the atmosphere that absorbs terrestrial heat, therefore, increasing the thermal energy levels on the earths surface (Andrews, Gregory, Webb & Taylor, 2012).

nQuestion 4

nTropical and boreal forests are major carbon dioxide sinks and they also lead to the cooling of the earths surface through evapotranspiration. Loss of these forests leads to a positive feedback to global warming through increased amount of carbon dioxide and heat in the atmosphere (Bessou, Ferchaud, Gabrielle & Mary, 2011). Volcanic eruptions resulting in the release of sulphur dioxides, carbon dioxide, and other gases increases the number of reflective substances in the stratosphere which leads to cooling of the earths surface and the process continues through a negative feedback process. Evaporation resulting in the formation of more clouds in the atmosphere leads to a negative feedback to climate forcings. Suns radiation is reflected back into space by these clouds, therefore, cooling the earth (Andrews, Gregory, Webb & Taylor, 2012). Biomass combustion leading to the release of ashes into the atmosphere leads to increased absorption of infrared energy from the earths surface and the cycle continues through positive feedback. Fossil fuel combustion resulting in the release of carbon dioxide into the atmosphere leads to increased global warming because carbon dioxide is a powerful positive radiative forcing. This cycle repeats through positive feedback.

nQuestion 5

nThe ocean influences the climate in three main ways. Firstly, the ocean plays the role of retaining solar energy from the sun, therefore, reducing the amount of heat radiated back into space. Secondly, through ocean currents, solar radiation is redistributed in the atmosphere (Church et al., 2011). This heat is distributed in the form of latent heat resulting from the evaporation of ocean water. Thirdly, ocean currents change weather patterns through various current movement patterns. There are two main ways in which greenhouse gases are affecting the dynamics of the sea. Firstly, greenhouse gases increase the oceans concentrations of carbon dioxide which reduces the ability of the ocean to absorb more carbon dioxide from the atmosphere (Bessou, Ferchaud, Gabrielle & Mary, 2011). The increased temperature levels in the ocean also reduce the ability of the ocean to absorb carbon dioxide because the gas is absorbed in cold water.

nPart B: The Cryosphere and Polar Amplification

nQuestion 1

nCryosphere is a region of earth covered by water in the solid form (Fountain et.al, 2012). The changes in the earths energy budget brought about by increased incoming solar radiation and decreased outgoing energy from the earth have led to increased global warming. This, in turn, has led to melting of the snow in the cryosphere (Fountain et.al, 2012). This leads to a positive feedback to the climate forcings. This is because the snow is useful in reflecting back suns radiation, therefore, cooling the earth. Its depletion, therefore, increases the heat energy levels on the earths surface. The Arctic is said to be undergoing polar amplification due to the growing decrease in the cryosphere resulting from increased warming in the region (Lenton, 2012).

nQuestion 2

nPermafrost soils are major reservoirs of carbon dioxide. Warming of permafrost soils leads to the release of methane and carbon dioxide in the atmosphere and the cycle reinforces through a positive feedback (Lenton, 2012). This leads to global warming in the Arctic. The thermohaline gradient relates to the different levels of heat and salinity in the ocean water. The thermal forcing and the haline forcing control the circulation of the conveyor belt in the ocean. When the haline forcing levels increase, the conveyor belt weakens (Lenton, 2012). This regular change in the conveyor belts strength influences climatic variations in the Arctic. This is due to reduced amount of water to sink carbon dioxide which affects global warming. The sea ice and Greenland ice sheet loss would lead to a positive feedback to climate forcings. This is because they are responsible for cooling the earths surface by radiating heat energy to space (Andrews, Gregory, Webb & Taylor, 2012).

nPart C: Climate Change Mitigation and Adaptation

nQuestion 1

nThe following are ways of mitigating climatic changes. Firstly, people should shift to using renewable energy sources that emit fewer greenhouse gases (Reddy, 2014). Secondly, the existing carbon sinks should be preserved through conservation of forests and oceans. Thirdly, human beings should create new carbon sinks for instance through green agriculture (Reddy, 2014). All these efforts would aid in reducing the carbon levels in the atmosphere thereby maintaining climatic stability. From my footprint evaluation, the lifestyle of using vehicles to commute is the most challenging to change. This is because unlike walking or cyclic, driving is very convenient and fast. However, use of energy economically is an easy lifestyle to adopt such as developing a habit of turning off lights when not in use.

nQuestion 2

nIn devising effective policies of climate adaptation concerning water resources, the government should consider the following factors: the population of people which affects the demand of water and the cost of policies adopted to conserve water resources. About agriculture and forestry, when formulation climatic changes adaptation policies, the government should consider the demand for food by people depending on the population of people and also the amount of land available for reclamation (Reddy, 2014). In setting effective strategies on human health and environmental refugees, the government should ensure that they consider the living standards of the people and eating behaviours so as to identify the most efficient policies. In formulating policies relating to biodiversity, the government should put into consideration the availability of natural habitats and the views of the general public towards such a move. In formulating policies on the development of Northern communities, the government should consider the existing systems and the view of people towards these policies.

nQuestion 3

nPolar bears are adapted to cold environments especially on the sea ice. These predators feed on the seals which are found in the seas (Stirling & Derocher, 2012). The polar bears can live in both terrestrials in aquatic habitats. Polar bears should be designated under Canada Species Risk Act due to their endangered nature resulting from climatic changes. Climatic changes have led to melting of sea ice which is the natural habitat for polar bears (Stirling & Derocher, 2012). This has also resulted in loss of the predators source of food which is seal found in sea ice.

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nReferences

nAndrews, T., Gregory, J., Webb, M., & Taylor, K. (2012). Forcing, feedbacks and climate sensitivity in CMIP5 coupled atmosphere-ocean climate models. Geophysical Research Letters. vol. (39), no. (9), n/a-n/a. http://dx.doi.org/10.1029/2012gl051607

nBessou, C., Ferchaud, F., Gabrielle, B., & Mary, B. (2011). Biofuels, Greenhouse Gases and Climate Change. Sustainable Agriculture Vol. (2), pp. (365-468). http://dx.doi.org/10.1007/978-94-007-0394-0_20

nChurch, J., White, N., Konikow, L., Domingues, C., Cogley, J., & Rignot, E. et al. (2011). Revisiting the Earth’s sea-level and energy budgets from 1961 to 2008. Geophysical Research Letters. vol. (38), no. (18), n/a-n/a. http://dx.doi.org/10.1029/2011gl048794

nFountain, A. G., Campbell, J. L., Schuur, E. A., Stammerjohn, S. E., Williams, M. W., & Ducklow, H. W. (2012). The disappearing cryosphere: impacts and ecosystem responses to rapid cryosphere loss. BioScience, vol. (62), no. (4), pp. (405-415).

nLenton, T. (2012). Arctic Climate Tipping Points. AMBIO, vol. (41), no. (1), pp. (10-22). http://dx.doi.org/10.1007/s13280-011-0221-x

nReddy, P. (2014). Climate Change Mitigation. Climate Resilient Agriculture For Ensuring Food Security, pp. (273-339). http://dx.doi.org/10.1007/978-81-322-2199-9_13

nRosenfeld, D., Sherwood, S., Wood, R., & Donner, L. (2014). Climate Effects of Aerosol-Cloud Interactions. Science, vol. (343), no. (6169), pp. (379-380). http://dx.doi.org/10.1126/science.1247490

nStirling, I., & Derocher, A. (2012). Effects of climate warming on polar bears: a review of the evidence. Global Change Biology, vol. (18), no. (9), pp. (2694-2706). http://dx.doi.org/10.1111/j.1365-2486.2012.02753.x