Global Change and Loss of Biological Diversity

Any changes that alter the self perpetuating nature of the world are termed as a global change. The global changes interfere with the global fluid envelopes that include land, the oceans and the atmosphere. Global changes are experienced all over the world. These global changes include changes in the atmospheric composition of gasses, the decreasing ozone concentration, the climate change and their consequences. The climate changes and other global changes have resulted into unpredictable weather conditions and widespread famines, changes in the land use, invasion of biologically sensitive resources and changes, increased ultraviolet radiations from the space and general changes in the atmospheric compositions. All these changes are a threat to the global biodiversity.

Global change and Biodiversity
The global warming among other global changes that have been experienced over the last few decades has raised major concerns on the future of the global environment. The ability of the earth to support and sustain the biodiversity is at stake due to the global changes that have been experienced over the last century. The changes are a threat to the human race as well as general biological diversity of the world. Scientist argues that with the current trend, the earth will not be able to sustain the human civilization in the next few centuries. This is evident from the increasing concentration of carbon and other greenhouse gases in the atmosphere, the increased temperatures as a result of global warming, melting of the ice sheets and submerging of the sea line. The rate at which animal and plant species are getting extinct is also worrying.
There is no doubt that many of the global changes that are being experienced today are man driven, either directly or indirectly. The global changes may either be biophysical which affect the physical world as well as the biological diversity or they may be social and economical changes that affect the lives of human beings and their interaction with the physical and biological world. These changes includes the general alteration of the global biological fabric, flows and distribution of chemical elements such as carbon, sulphur, nitrogen and the metals and the global energy balances. These changes are direct impacts of changes in the land use, changing the land cover, industrialization and globalization, increased population, increased use of fossils oils and encroachment of natural resources among others.

Antropocene also has been used to explain the global changes that have been experienced throughout the history of the earth. This approach looks at the Holocene and the impacts of human society development on the environment. Holocene is the periods in the history of the world that came after the glacial geological period. During this period, there have been changes in the activities of the human kind that have had a big impact on the earth and as consequently led to global changes. Important advancements in this period includes the invention of fire, development of agriculture, invention of fossil fuel energy and machines, industrialization and the explosive increase in the world population in the 19th and 20th century. During the Holocene era, human activities have become the driving force on the morphological and geological changes in the earth. Mans activities have modified the physical and biological aspects of the earth.

Mans effect on the earth system cannot be quantified. The power of man on earth has been compared to the power of earth itself. It is true that man has either inhabited or visited all parts of the world. Man has even extended his influence beyond the earth releasing communication gadgets to the space and landing in the moon. Biologists and geologists identified the great influence of human kind on the global environment in the early 20th century in the rise of industrialization. Over the years, these human influences on the environment have attracted a lot of attention among biologists and environmentalists. The changing human activities in the world are directly responsible for the loss of biological diversity. Unless measures to reduce the influence of human activities on the physical and biological fabric are controlled, the globe may be unable to support the biological diversity in the near future.

Since the industrial revolution, the increased carbon gases concentration in the atmosphere has been the greatest threat to the biological diversity. The increased carbon dioxide and other greenhouse gases concentration in the atmosphere over the last century are well documented. The increased dependency on fossil fuels as a result of massive industrialization in the 20th century is the basic cause of the increased carbon dioxide concentration in the atmosphere. Another factor that has also played a major role is the encroachment of natural forests. The rapid increase in population has created the need for more land for food production through agriculture as well as for human settlement. This increased clearing of forest has disrupted the self perpetuating carbon cycle.

Scientific analysis that have been carried in the second half of the 20th century indicated that the concentration of carbon dioxide increased from about 315 ppm in the mid twentieth century to about 350 ppm towards the end of the century. The analysis also indicated that the rate of increase in the concentration increased over the interval. The increase in the carbon dioxide concentration being experienced in the modern time is estimated to be equal only to the increase experienced in the glacial interglacial era which resulted into global changes and affected the global biological diversity significantly. However, the historical changes in the concentrations of gases in the atmosphere were as a result of natural causes while the current changes are as a result of human causes.

Recent research indicates that the increases dependence of the world economy on fossil fuel is the primary cause of the increased carbon in the atmosphere. The encroachment of natural forests for agriculture, settlement and industry and infrastructure development and changes in land use has been rated as the secondary causes of the carbon increase. The increased carbon dioxide from burning fossil fuels has altered the natural balance between the isotopes of carbon in the atmospheric carbon dioxide. Carbon dioxide from fossil fuel is carbon -13 depleted and has thus diluted its concentration in the atmosphere. The result has been increased concentration of carbon-12 and carbon-13 which has adverse effects on the food chain. Any alteration that affects the food chain is a threat to the global biological diversity. The increased carbon dioxide has had negative impacts on the ozone layer and general reduction in air quality especially in industrial areas and busy cities.

There are other gases that have been associated with global changes that threaten the ecosystem of the world and the biodiversity. Chemicals such as the deadly chlorofluorocarbons in the ecosystem have increased significantly. The concentration of methane gas in the atmosphere has increased tremendously over the years and scientists have estimated that its concentration has doubled over the last two and half centuries. This has been as a direct consequence of the increased agricultural and industrial activities over the same period of time. Nitrogen imbalance as a result of increased use of nitrogenous fertilizers in agriculture has also been reported with an increase in the concentration of oxides of nitrogen in the atmosphere.

The immediate effects of the increased concentration of greenhouse gases in the atmosphere are the climate change the world is experiencing today. It is one of the global changes that have impacted negatively on the ecosystem leading to loss of diversity. More solar radiations are reaching the earths surface as a result of the depletion of the ozone layer which acts it as a filter. Some of the impacts of climate changes are the increased global temperatures, unpredictable weather, increased floods and drought. For over three decades, the impacts of greenhouse gases on the ozone layer have been known to the scientists. The gases have been known to catalyze the break down or react irreversibly with the ozone layer leading to its depletion. The increased radiations from the space have adversely affected plants, animals, human beings and the world ecosystem in general.

Scientists have also reported an increase in carbon in the soil which affects the ecosystems in the soil and the atmosphere as a result of increased decomposition. There are numerous species of microorganisms that have been found in the soil. These microorganisms play an important role in maintaining the quality of soil. The terrestrial ecosystems have also responded negatively to the increased concentration of carbon gases in the atmosphere and the resultant climate change. This has resulted into permafrost thawing and the associated decomposition of frozen materials. This occurs as a result refreezing of organics materials which have resulted into increased carbon into the ecosystem as more frozen carbon undergoes microbial decomposition.

The increased temperatures are continuously and catastrophically exposing the frozen carbon to microbial activities which is estimated by scientists to be up to twice the atmospheric carbon. The thawing of the permafrost combined with other impacts of the climatic change is slowly turning life on earth to extinct. The changes in the plants growth rate as a result of increased carbon, and the energy changes have not shown any sign of compensating the increase in carbon concentration as a result of microbial decomposition of thawing permafrost. Though the process is slow, in the long run, the increased carbon will be catastrophic and will affect the ability of the earth to support the diverse biological ecosystem.

The rate at which different mans activities which have led to various global changes is causing animal and plant species to become extinct is alarming. Scientific research indicates that all biological species in the world are ephemeral under natural conditions where episodes of mass extinction occur rarely and after thousands or millions of years. It is estimated that a species exists in the ecosystem for an average of ten million years before becoming extinct naturally. Human activities have however affected the biodiversity of the world where the rate of extinction has been raised several folds above the natural background rate. This increased rate is directly as a result of changes in the land use and encroachment of natural ecosystems, biological invasions and the increased environmental degradation.

Scientists estimates that if the current trend at which species are becoming extinct is maintained, most of the plants and animal specials will disappear from the ecosystem in the next one or two centuries and the biological diversity enjoyed in the world will be lost. The world will experience mass extinction that has never been experienced in the earths history since the Cretaceous Tertiary Boundary. Man has intentionally or inadvertently invaded the biodiversity for many years. He has eliminated some species in the ecosystem while at the same time introducing others altering the natural balance. The wave of globalization has increased the mobility of humans. As the human becomes mobile, the plant and animal spaces have also become more mobile leading to biological invasion. The long term effect of this mobility is the loss of biological diversity as the biota of the whole planet become homogeneous.

The realities of global changes are becoming more evident in the world. It could have been difficult to explain the impacts of high concentration of greenhouse gases half a century ago, but today, the impacts are almost obvious. There are many global changes that have happened as a direct impact of the human activities in the globe. Moreover, many of the global changes are intertwined. For this reason, biological diversity has been threatened by the global changes that are influenced by mans activity. The biodiversity is being lost at an alarming rate.


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