CLIMATE CHANGE

CLIMATE CHANGE

Anthropogenic (human –caused) climate change is an established phenomenon. The biggest culprit in climate change is an increase in atmospheric carbon dioxide, which is generated primarily through burning of fossil fuels. Climate is the prevailing weather condition in an area. The four main abiotic factors: Temperature, water,, sunlight and wind are the major components of climate. Climate factor, especially temperature and water, have a major influence on the distribution  of organisms,. Climate patterns can be described on two scales: Macroclimate patterns are on global, regional or local levels and Microclimate patterns are very fine patterns such as the conditions experienced by a community of organisms under a fallen log. Forest trees moderate the micro-climate beneath them. Deforestation  cleared  area therefore experiences greater temperature extremes than the forest interior. Climate determined the makeup of biomes which are the major types of ecosystems. Global climate patterns are determined  by sunlight and earth’s movement in space. The sun’s warning effect on the atmosphere , land and water establishes the temperature variations cycles of air movement and evaporation of water that are responsible for latitudinal variations in climate.

  Ocean currents influence climate along the coast by heating and cooling overlying  air masses,

which may pass over land. Coastal regions are generally more moist than inland area of same latitude. In general, oceans and large lakes moderate the climate of nearby terrestrial environments. Oceans currents also influence climate in coastal areas. Mountains have significant effect on the amount  of sunlight reaching  an area, as well as on local temperature and rainfall. These environmental differences affect species distribution. At any given latitude, air  temperature declines 6°C with every 1,000 meter increase  elevation. As most warm air approaches a mountain, it rises and cools down, releasing moisture on the windward side of the peak. Deserts commonly occur on the leeward side of the  mountain ranges. The changing angle of the sun over the course of a year affects the local environments. Belts of wet and dry air on either side of the equator shift with the changing angle of the sun. Lakes are also sensitive to seasonal temperature changes. During the summer and winter, many temperate lakes are thermally stratified or layered vertically according to temperature. These lakes undergo a semi-annual mixing or turnover of their waters in spring and fall. Turn –over brings oxygenated water to the bottom and nutrient –rich water to the surface.

   Long –term climate changes profoundly affect the biosphere. One way to predict possible effect of current climate changes is to consider the climatic changes that have occurred in temperate regions since the end of the last ice age. There are latitudinal pattern of climate over the earth’s surface; there are also latitudinal patterns of biome distribution. A climograph denotes the annual mean temperatures are precipitation of a region. Each biome has a characteristic climograph. Biomes are dynamic; and natural disturbance, rather than stability, tends to be the rule.