Sea Level Rise
Sea level rise is an important and remarkable phenomenon nowadays, because of global warming. There are two main reasons for the sea level rise; one is the thermal expansion and the second is melting of glaciers.
The psychical property of water; warm water takes up more space than cold water. So when the ocean water warms with increasing temperatures because of global warming, it expands and has a higher volume, and sea level rises [1]. Melting of glaciers and ice sheets adds freshwater to the ocean or sea, and the sea level increases.
With the paleo studies it is understand that the global mean sea levels have risen about 5 m from the past to the future, and the global mean temperature was 2°C warmer [1]. This increasings in the global mean sea level and the global mean temperatures were in the last two centuries. Thermal expansion and melting of glaciers were the dominant mechanisms for the sea level rise. Today’s data tells us that the global mean sea level rise may continue for many centuries, and it depends on future emissions [1]. With global warming , the mean sea level in the world rises 11–16 cm in the twentieth century [7]. As the emissions getting more increasing day by day, the experts predict the rise of about 2m at the end of the twenty-first century [8].
To become ready for the adverse effects of the global mean sea level rise risks, future scenarios are created by the researchers and institutes. With this modeling studies, the future behavior of the global mean sea level rise is trying to estimate, and precautions may be taken.
Global Warming
Since the industrial revolution, due to the rapid increase in the atmospheric accumulation of greenhouse gases released into the atmosphere through various human activities such as the burning of fossil fuels, deforestation, and industrial processes, increases the temperature of the earth and the lower parts of the atmosphere. This process is called Global Warming.
Greenhouse gases, such as carbon dioxide (CO2), methane (CH4), and ozone (O3), absorbs the thermal radiation and spread it to the atmosphere. Because of the increase of thermal radiation, the atmosphere is warming.
The largest temperature increases on the earth was in the last 100 years. The average temperature is increased by about 1 degrees Celsius in the last decade [6]. Lots of greenhouse gases are released into the atmosphere with human activities. These greenhouse gases once released, the atmosphere stays for decades without disappearing. In the Intergovernmental Panel on Climate Change (IPCC), it has been announced that carbon dioxide and methane levels have increased by 35 % and 148 % since the industrial revolution.
Sea Level Rise Risks
As the sea levels are increasing rapidly, risks of it started to affect humanity. There are significant and vital risks due to the rising of sea levels. The most important one is the loss of coastal settlements, infrastructure, and ecosystems [3]. At low elevation lands, sea-level rise risk is too much [4]. An estimated 1 billion of the world’s population lives within coastal zones below the 10-m elevation area, and rising seas are already affecting low-lying regions [5]. Sea level rise also a potential threat for losing properties and lands, renewable and subsistence resources and tourism, recreation, and coastal habitats [2]. It has a significant ımpacts on agriculture, water quality, and soil loss near the coastal areas. All of these risks may damage humans, human activities, and the built of the environment.
Conclusions
There are lots of evidence for the occurance of global warming and sea-level rise. Past studies show that there is a 5 m sea level rise and the world is 2°C hotter than the past. Humanity has to take precautions to decrease greenhouse gas emissions as the primary cause of global warming. The scenarios studies show that if we do not decrease the emissions, the sea level rise will be a real problem for the coastal zones. This affects about 1 billion people who live in coastal regions. In the coastal areas, we have to be well prepared for the risks of the sea level rise to decrease the level of losses. Land use planning, decision analysis, protection of infrastructures, ecosystem adaptation precautions must be taken.
REFERENCES
[1] J. A. Church, P. U. Clark, Sea Level Change, Fifth Assessment Report of the Intergovernmental Panel on Climate Change Page 1137, (2013)
[2] I. Curebal, R. Efe, A. Soykan, S.Sonmez, Climate change and Sea level rise: Potential impact on the coast of the Edremit Plain, NW Turkey, Geophysical Research Abstracts, Vol. 17, (2015)
[3] R.Kopp, R. M. Horton, C. Little, J. Mitrovica, M. Oppenheimer, D. J. Rasmussen, B. H. Strauss, C. Tebaldi, Probabilistic 21st and 22nd century sea-level projections at a global network of tide-gauge sites, Earth’s Future, page383, (2014)
[4] R. J. Rowley, J. C. Kostelnick, D. Braaten, X. Li, J. Meisel, Risk of Rising Sea Level to Population and Land Area, EOS, Vol. 88, №9, (2007)
[5] G. McGranahan, D. Balk, B. Anderson, The rising tide: assessing the risks of climate change and human settlements in low elevation coastal zones, Environ. Urbanization, pages. 17–37, (2007)
[6]Shahzad, U., Global Warming: Causes, Effects and Solutions, Durreesamin Journal, Vol 1 Issue 4 , (2015)
[7] S. Dangendorf, et al Reassessment of 20th century global mean sea level rise. Proc. Natl Acad. Sci. 114, (2017)
[8] A. Nauels, , M. Meinshausen, , M Mengel, K.Lorbacher, T. M. L. Wigley, Synthesizing long-term sea level rise projections the MAGICC sea level model v2.0. Geoscientific Model Dev. 10, (2017).
