Life

Life

Though there is no universal agreement on the definition of life, scientists generally accept that the biological manifestation of life is characterized by organization, metabolism, growth, adaptation, response to stimuli and reproduction. Life may also be said to be simply the characteristic state of organisms.

Properties common to terrestrial organisms are that they are cellular, carbon-and-water-based with complex organization, having a metabolism, a capacity to grow, respond to stimuli, and reproduce. An entity with these properties is generally considered life. However, not every definition of life considers all of these properties to be essential. Human-made analogs of life may also be considered to be life.

Wilderness

Wilderness is commonly defined as a natural environment on Earth that has not been significantly modified by human activity. The Wild foundation goes into more detail, defining wilderness as: "The most intact, undisturbed wild natural areas left on our planet - those last truly wild places that humans do not control and have not developed with roads, pipelines or other industrial infrastructure." Wilderness areas and protected parks are considered important for the survival of certain species, ecological studies, conservation, and recreation. Wilderness is deeply valued for cultural, spiritual, moral, and aesthetic reasons. Some nature writers believe wilderness areas are vital for the human spirit and creativity. The word, "wilderness", derives from the notion of wildness; in other words that which is not controllable by humans. The word's etymology is from the old English wildeornes , which in turn derives from wildeor meaning wild best (wild + deor = beast, deer). From this point of view, it is the wildness of a place that makes it a wilderness. The activity of people does not disqualify an area from being "wilderness." Many ecosystems that are influenced by activities of people may still be considered "wild." This way of looking at wilderness includes areas within which natural processes operate without very noticeable human interference.

Climate

The temperatures, humidity, atmospheric pressure, winds, rainfall, atmospheric particle count and numerous other meteorological elements in a given region over long periods of time, as opposed to the term weather, which refers to current activity of these same elements known as Climate. The climate of a location is affected by its latitude, terrain, altitude, persistent ice or snow cover, as well as nearby oceans and their currents. Climates have to be classified using parameters such as temperature and rainfall to define specific climate types. The Thornthwaite system, in use since 1948, incorporates evapotranspiration in addition to temperature and precipitation information and is used in studying animal species diversity and potential impacts of climate change.
Paleoclimatology is the study and description of ancient climates using information from both non-biotic factors such as sediments found in lake beds and ice cores, and biotic factors such as tree rings and coral, and can be used to extend back the temperature or rainfall information for particular locations to a time before various weather instruments were used to monitor weather conditions. Climate mode are mathematical models of past, present and future climates and can be used to describe the likely patterns of future changes.

Defination of Climate:

Climate (from Ancient Greek klima, meaning inclination) is defined as the weather averaged over a long period of time. The standard averaging period is 30 years, but other periods may be used depending on the purpose. Climate also includes statistics other than the average, such as the magnitudes of day-to-day or year-to-year variations. The Intergovernmental Panel on Climate Change glossary definition is:“

Climate in a narrow sense is usually defined as the "average weather," or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization. These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system

The difference between climate and weather is usefully summarized by the popular phrase "Climate is what you expect, weather is what you get. Over historical time spans there are a number of static variables that determine climate, including latitude, altitude, proportion of land to water, and proximity to oceans and mountains.

Definition of weather

Weather is the sequence of the states of the atmosphere as time passes. We know, the behavior of the atmosphere at a given place can be described with number of quantities characterizing the physical state of the air, such as its temperature, pressure, water content and motion .
Generally, we define climate as an ensemble of all the states of the atmosphere at a place experienced in the course of years and over the years of some large but finite time interval. The expression of the length of the time interval could be ’sufficiently long’ but finite’, for which we have a free choice to take a sample of the atmosphere’s states, does not seem very scientific.

Though weather is the sequence of states of the atmosphere, it is tempting to define a ”true” climate in terms of a limit as the time interval approaches infinity, e.g. it is the total ensemble of the atmospheric states which ever occurred in the past. But the questions arise: how can we arrive at and what can we do with such an abstract idea? The practical difficulty is computing the statistical properties of an infinite time series, what is impossible. The theoretical difficulty is that we would not be able to consider the change of this type of climate.

Universally accepted convention recommended by the World Meteorological Organization that the 30-year period is a basic climatic time scale, and the statistical properties calculated for the consecutive 30-year periods 1901-1930, 1931-1960, and most frequently used 1961-90. Are considered and called climatologically standard normal.

Now at present the climate is changing rapidly, climate characteristics are sometimes re-calculated every 10 years for the period of the recent 30 years, i.e. 1961 - 1990, 1971 - 2000, ... although the next official period would be 1991 - 2020. These fixed time intervals allow world-wide comparison of climatological events. For example, the suitable climatic time scales are completely different in case of initiation of the cultivation of a new plant from those needed for investigating the glacial chronology.

Pollution

Pollution is the process of making air, water, soil, etc. dirty; the state of being dirty. Pollution is also the introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances such as noise, heat, or light energy. Pollutants, the elements of pollution, can be foreign substances or energies, or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels. Pollution is often classed as point source or nonpoint source pollution.

Air pollution

Air pollution is occurred by the release of chemicals and particulates into the atmosphere. Common gaseous air pollutants include carbon dioxide (CO₂ ), sulfur dioxide (SO₂), chlorofluorocarbons (CFC) and nitrogen oxides (NO₂) produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight.

Water pollution

Water pollution is occurred by the release of waste products and contaminants into surface runoff into river drainage systems, leaching into groundwater, liquid spills, wastewater discharges and littering.

Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, herbicides, pesticides and chlorinated hydrocarbons.

Sources and causes

Air pollution is created by both natural and manmade sources. Though globally manmade pollutants from combustion, construction, mining, agriculture and warfare are increasingly significant in the air pollution equation.

Motor vehicle emissions are one of the leading causes of air pollution. Japan, United States, China, Mexico and Russia are the world leaders in air pollution emissions. Principal stationary pollution sources include chemical plants, coal-fired power plants, oil refineries, petrochemical plants, nuclear waste disposal activity, incinerators, large livestock farms (dairy cows, pigs, poultry, etc.), PVC factories, metals production factories, plastics factories, and other heavy industry. Agricultural air pollution comes from contemporary practices which include clear felling and burning of natural vegetation as well as spraying of pesticides and herbicides

Some of the more common soil contaminants are chlorinated hydrocarbons (CFH), heavy metals (such as chromium, cadmium--found in rechargeable batteries, and lead--found in lead paint, aviation fuel and still in some countries, gasoline), MTBE, zinc, arsenic and benzene. In 2001 a series of press reports culminating in a book called Fateful Harvest unveiled a widespread practice of recycling industrial byproducts into fertilizer, resulting in the contamination of the soil with various metals. Ordinary municipal landfills are the source of many chemical substances entering the soil environment (and often groundwater), emanating from the wide variety of refuse accepted, especially substances illegally discarded there, or from pre-1970 landfills that may have been subject to little control in the U.S. or EU. There have also been some unusual releases of polychlorinated dibenzodioxins, commonly called dioxins for simplicity, such as TCDD.

Pollution can also be the consequence of a natural disaster. For example, hurricanes often involve water contamination from sewage, and petrochemical spills from ruptured boats or automobiles. Larger scale and environmental damage is not uncommon when coastal oil rigs or refineries are involved. Some sources of pollution, such as nuclear power plants or oil tankers, can produce widespread and potentially hazardous releases when accidents occur.

In the case of noise pollution the dominant source class is the motor vehicle, producing about ninety percent of all unwanted noise worldwide.