Biosphere & Extinction of Life

Importance Biosphere for our existence on earth

The biosphere is the space on or near Earth's surface that contains and supports living organisms. It is subdivided into the lithosphere, atmosphere, and hydrosphere. The lithosphere is Earth's surrounding layer, composed of solids such as soil and rock; it is about 80 to 100 kilometers (50 to 60 miles) thick. The atmosphere is the surrounding thin layer of gas. The hydrosphere refers to liquid environments such as lakes and oceans that lie between the lithosphere and atmosphere. The biosphere's creation and continuous existence results from chemical, biological, and physical processes. The entire range of living matter on Earth from whales to viruses and from oaks to algae could be regarded as constituting a single living entity capable of maintaining the Earth's atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constituent parts

The days of resources  crisis is at our doorstep and is going to make imbalance in every field  on which our existence depends. Off late we hear the word sustainability everywhere as we realize  the effect of resource scarcity on our daily life. The basic resources are given by God free on which our life fully depends ie air, water, food. But in the  last 50 years our industrialization has progressed at a very fast rate and has polluted the total nature- air, earth, water the total biosphere which is vital for our existence This had resulted detrimental effect on generation of food , water and other renewable resources. The outcome of use of fossil fuel is  increase of carbon dioxide and other gases causing  global warming which is going to effect  weather adversely effecting  supply of basic needs ie food and water resulting end of man on earth.

Evolution of the biosphere

During Earth's long history, life-forms have drastically altered the chemical composition of the biosphere. At the same time, the biosphere's chemical composition has influenced which life-forms inhabit Earth. In the past, the rate at which nutrients were transformed from one chemical form to another did not always equal their transformation back to their original form. This has resulted in a change in the relative concentrations of chemicals such as carbon dioxide and oxygen in the biosphere. The decrease in carbon dioxide and increase in atmospheric oxygen that occurred over time was due to photosynthesis occurring at a faster rate than respiration. The carbon that was present in the atmosphere as carbon dioxide now lies in fossil fuel deposits and limestone rock.

Scientists believe that the increase in atmospheric oxygen concentration influenced the evolution of life. It was not until oxygen reached high concentrations such as exist on Earth today that multi cellular organisms like ourselves could have evolved. We require high oxygen concentrations to accommodate our high respiration rates and would not be able to survive had the biosphere not been altered by the organisms that came before us.

Causes for concern

All life on our planet exists in a delicate balance, a system of interdependency among plants, animals, insects, microorganisms, and the environments in which they live. The earth supports a variety of different ecosystems in the air, water, and land—and each ecosystem, ultimately, is dependent upon all the others for its survival. Humans have been slow to learn this simple yet vitally important lesson. Carelessly and ruthlessly, we have hunted animal species to the brink of extinction, cleared away forests, and released poisons into the environment. We are only recently learning that if we cause an environmental crisis, or destroy a single habitat, even far away—in the sea, under the earth, or on another continent—we are indirectly affecting every creature on this planet and ultimately hurting ourselves.

Destruction of the Hydrologic (Water) Cycle results loss of Forest and Agriculture

Saltwater evaporates from sun's energy producing fresh water in clouds, leaving salts in the ocean. Water vapor cools and condenses to precipitation over oceans and land. Runoff forms freshwater lakes, streams, ponds, groundwater, and is held in plants and transpired. Some water infiltrates the ground, becoming part of the groundwater, returning very slowly to the oceans. Although the water cycle, shows water to be a renewable resource, only about 3% of that water is fresh and suitable for human use. Water may be polluted or inadequate for human populations concentrated in specific areas.

Disruption of the Biosphere

Human technology and population growth can directly and indirectly disturb the biosphere. They key question now is: can humans cause global climate change? The human population has experienced phenomenal exponential growth since the Industrial Revolution. Modern agriculture and medicine have increased growth rates for our population, resulting in over 90 million people added each year. United Nations estimates indicate a human population of 10 billion may exist by the end of the twenty-first century.

Human populations are in a growth phase, Since evolving around 200,000 years ago, our species has proliferated and spread over the Earth. Beginning in 1650, the slow population increases of our species exponentially increased. New technologies for hunting and farming have facilitated this expansion. It took 1800 years to reach a total population of 1 billion, but only 123 years to reach 2 billion, and a mere 37 years to reach 4 billion. 17 years to reach 5 billion, 11 years to reach billion and now 10 years to reach 7 billion ie each year around 100 million, new people join the human race. This is roughly equivalent to adding three Canadas or another Mexico to the world annually

This is depleting the resources of mother earth beyond recovery and we are on a course to extinction with mankind ahead of all species . Human body is very sensitive to nature and cannot adopt to its change as other species and run to extinction ahead of all other species.