The main purpose of this research paper is to discuss whether there is any proof and evidence of global climate change, as the debates about this question have been conducted until nowadays. First, it should be mentioned here that any climate change is a long-lasting considerable change in any statistical form of weather pattern`s distribution for different time periods that can vary from years and decades to thousands and millions of years. For example, it can be a change in weather conditions, or distribution of them per average conditions. It`s usually caused by different factors of biotic origin like solar radiation variations received by Earth, volcanic eruptions, plate tectonics, etc. The interesting fact is that for the last decades, the human factor or the human effect on the environment has also become significant in describing and solving climate change problem.
Obviously, scientists are doing their best to figure out how the past, present and future climate changes occur and develop by conducting different researches using various theoretical models, experiments and observations. An existent record of climate, which registers every climate change from the deep past of the Earth till nowadays continues to register all the necessary changes, based on records of geological researches including temperature profiles, accumulations of ice, records about flora and fauna, records of levels of seas etc. As all this information is being continuously collected and studied, the results of such research usually appear to be the source for the theoretical explanations of past climate data; furthermore, the results of these explanations are usually matched and used for the future predictions of future climate changes.
Needless to say, the climate of Earth has been continuously changing from year to year. During the last 650 thousand years a number of seven glacial change`s cycles has occurred, including the last ice age that was dated approximately 7 thousand years ago, beginning the era of human civilization. The majority of these changes was described by slight variations of an orbit of the Earth, eventually changing the amount of solar radiation received by the planet.
There`s a hazardous trend of a great significance regarding the modern climate change, as it`s found to be caused by the human actions. The most dangerous aspect of this trend that the rate of climate changes has become unprecedented for the last thousand years. Moreover, the technological developments and advancements like artificial satellites of the Earth`s orbit made the broader and more exact vision of the planet for the scientists possible; therefore, they`ve got enough information to collect and study, proving the significant impact of the human actions on the state of planet, including its climate. Therefore, the scientists proved some factors caused the climate change that are nowadays undisputable.
The nature of carbon dioxide and its hazardous effect on the temperature of the planet due to the infrared energy transfer within the atmosphere is well known to everyone; moreover, the ice cores of Antarctica and Greenland are continuously melting, increasing the sea levels from year to year. As a result, the evidence of climate change due to the carbon dioxide impact is also undeniable. Moreover, such changes have happened in a couple of decades of years and not even in thousands or millions years, as it was before; therefore, the climate change due to the carbon dioxide emissions should somehow be regulated.
Let`s describe each aspect of climate change separately, as they provide the respective evidences of the continuous climate change. First, the usage of radiosonde balloons to record and register the atmospheric temperatures starting from the middle of 20th century and the satellite data obtained from the 1970s till nowadays proved that 18O/16O ratio in ice core and calcite samples found the reasons for the ocean temperature and the seas levels increase.
The most significant and sensitive indicators of climate change are the Glaciers, as their size is simple determined by the balance of input of snow and meltdown output; therefore, their size can be the simplest indicator for the climate change and the continuous temperature increase, visible by even a non-professional. With the temperature increase, glaciers will obviously start melting unless the amount of snow input will balance the melt; moreover, the converse of these two amounts is also real.
The growing and shrinking of glaciers are usually explained by the complex of various internal and external factors. The internal factors are the factors of nature and its variability in precipitation, temperature and hydrology, both subglacial and englacial. They have the potential of shaping the glaciers according to different climate conditions; therefore, the average dynamics of the size of the glaciers is the most exact index of the glaciers` melting impact on the climate change of the world per particular season. The total gathering of the average records of the glaciers melting is conducted constantly from year to year for the scientists to observe the potential climate change.
This gathering is well known under the name of a world glacier inventory, starting to exist and be compiled from the beginning of 1970s; it was initially based on the aerial researches and observations usually in the form of aerial maps and photographs; however, nowadays the information from satellites proved to be more exact and reliable. Such compilation registers the status of approximately 100,000 different glaciers that cover an area of more than 240,000 square kilometers with the remaining cover of ice of around 445,000 square kilometers.
An organization called The World Glacier Monitoring Service collects the information on the mass balance of glaciers and glacier retreat each year. According to this data, the glaciers through all over the world have been officially stated as significantly shrinking, providing the examples of the big glacier retreats of the 1940s, the growing or stable conditions within the 1920s and the 1970s; however, continuing to retreat starting from the middle of 1980s till nowadays.
The interesting fact is that the most important and considerable climate processes since the middle Pliocene era, which was more than three million years ago, are the interglacial cycles. For example, the current interglacial period, which is called the Holocene, has been existing for almost 11,700 years. The reactions like the rise and fall of ice sheets and the changes of sea levels caused and formed by different orbital variations eventually forced the climate to change drastically. However, there are also famous illustrations like Heinrich events and the Dansgaard-Oeschger events that prove the climate changes due to glacial changes without any orbital variations, despite the fact that they were natural in their origin. The continuous shrinkage of the glaciers, especially in the Arctic zones, is the undeniable evidence of constant climate change, as the decline of Arctic ice; both in thickness and extent prove this from year to year. As it`s well known, the sea ice in this region is the frozen water floating on the surface of the ocean and due to the fact that it covers the vast territories of the polar regions, it changes differently from season to season. For example, in the Arctic, the significant amounts of sea ice remain constantly; however, the areas of Antarctic Sea and the Southern Ocean are annually reforming and meting away. The observations from satellites provide the evidences that the ice of Arctic Sea is nowadays declining dramatically at a rate of 11-11.5% per each ten years.
Furthermore, a dependence between the temperature and the variations of global sea levels can be shown with the results of the analysis of ice retrieved from the ice sheets of the mentioned above regions. In addition, the air bubbles frozen within the ice sheets revealed the variations of CO2 in the atmosphere not only in the contemporary years that were mostly influenced by the human activities, but also from the distant past. Therefore, the studies of these cores of ice have become the significant indicators of not only ice sheet changes, but also the changes of CO2 in the historical aspect; moreover, they continue to give the valuable and considerable data about the differences between the modern and ancient climate conditions. Therefore, they officially prove every change of the climate from year to year, especially in the dynamics of global temperatures and sea levels that are the biggest climatic concerns nowadays.
As for the detailed explanation of the sea level change, it will be provided in the next paragraphs below. First, the contemporary increase of sea level is approximately 3mm per year through all over the world; moreover, according to the NOAA (National Oceanic and Atmospheric Administration of US) this increase is considerably of a bigger rate than the average increases of sea level for the last thousands of years with the great potential of further increase. Obviously, these increases constantly affect not only the human populations in island and coastal regions, but the marine ecosystems and other related environments and ecosystems, as well.
In the period within the 1870 and 2004, the average sea levels have increased a 1.46 mm per year; between 1950 and 2009, the same index showed the level of 1.7 mm per year, continuing to grow from 1993 to 2009, as it has reached the level of 3.3 mm per year, the fastest increase rate that was ever observed. As it was also described above, the two main reasons of the sea level rise are the thermal expansion, as the ocean waters expand with the temperature increase and the glaciers melting. Moreover, the rise of sea level has also become the extra proof of the warming of global climate, explained by the scientists with the impact of anthropogenic factors that have become the main reasons of the climatic changes of the 20th century.
Moreover, the sea levels are expected to rise more and more dramatically, as in 2007, the IPCC (International Panel on Climate Change) conducted a forecast that within the 21st century the sea level will rise on another 18 to 59 cm; however, these figures do not include the effects of ice sheet flow changes and the changes of CO2 cycle. The more updated data has been given by the US National Research Council, suggesting the potential sea level rise of between 56 and 200 cm within the 21st century, which is more than hazardous figure for nowadays.
A change in the climate may also be explained by the impact of change in vegetation, especially, its type, coverage and distribution. For example, some of these changes may result in the increased warmth and precipitation within a separate area, improving the growth of plants and subsequent isolation of airborne CO2. In addition, a continuous warmth`s increase within a region will result in an earlier fruiting and flowering times, changing the life cycles of the organisms dependent to these plants. On the contrary, the temperature decrease will cause the lag of life cycles of the plants, which may result in vegetation stresses leading to the desertification of the areas. The current climatic changes are dramatically changing the equatorial regions of Southern America and Africa, devastating the tropical rainforests and causing the many species of plants and animals to extinct.
The temperatures caused by the climate variations also affect the precipitation in different areas of the planet. Within the 20st century, an estimated precipitation of global land increased by almost 2%; however, the figure remains unstable due to the different calculation methods used by different Climate Control organizations. As for the physical impact of the precipitation, the examples of the Last Glacial Maximum that occurred 18,000 years ago caused the low evaporation from the oceans onto the landmasses of the continents, forming the deserts even in the Polar Regions. On the contrary, the warm Atlantic period dated 8,000 ago was much wetter than nowadays. Therefore, the amounts of precipitation are closely connected to the climate changes within different areas and territories, showing the potential consequences of the increase and decrease of precipitation onto them.
Another interesting indicator of the climate change from year to year is the analysis of pollen. There`s a complete field of study called Palynology, which researches the modern and fossil palynomorphs, and the pollen of different plants is not an exception. The study is used to include the distribution of plant species geographically, as it varies with the climate variations. For example, different plant groups have the separate and unique kinds of pollen, including different surface textures and forms; moreover, as the outer side of pollen is created of a very resilient material, it`s highly resistant to the decay. In addition, different changes in pollen`s type retrieved from different layers of sediment of rivers and lakes indicate the changes in plant groups. Obviously, such changes are the results of climatic changes within the area.
Summarizing all the information mentioned above, it should be stated that climate changes truly exist with the development and variation of different elements of the worldwide environment. Another question is the fast rates of these changes that are of the highest speed than ever in the history of humankind; furthermore, such changes are more than hazardous and can become the reason of the extinction of different species of plants and animals. In addition, the human population might also potentially decrease, as the majority of the planet`s territory will become not suitable for living despite the high adaptive skills of the humanity. The biggest concern nowadays is the ecological problem and the significant climate changes and it should be solved in the fastest possible way.
References
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NASA. (2013, 07). Climate change: How do we know? Retrieved from NASA Official Webpage: http://climate.nasa.gov/evidence/
NOAA National Ocean Service. (2014, 06 28). Is sea level rising? Retrieved from http://oceanservice.noaa.gov/facts/sealevel.html
Sarda Sahney, M. J.-L. (2010, 11 12). Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica. Retrieved from http://www.academia.edu/368820/Rainforest_collapse_triggered_Pennsylvanian_tetrapod_diversification_in_Euramerica
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