This article will help you acquire an understanding of the meaning of climate and it’s environmental implications.
Climate and Climate Change
The term “Climate” can be defined as a synthesis or amalgam of weather. In other words, it is the mean expectation of weather given period over a location or area. It can also be regarded statistical abstraction of actual weather experienced in an area long period of time.
This is why man sees climate as the average weather condition. The changeability of weather is a common phenomenon; this is because weather variation occurs frequently, often on a time scale of a few hours.
Climate variations are not a common occurrence because they occur much less frequently on a time scale of several years or hundreds of years.
Climate is a variable phenomenon with variations occurring on varying time scales. And that is why various terms are used to describe variations or fluctuations in climate and these are valid references to some appropriate time scales at which the variations or fluctuations are considered.
The term “climatic variability”, “variations” and “climate fluctuations” are used to express that the inherent variability of climate is not fixed or static but rather dynamic, and climatic trends occur only when fluctuations or variations (follow a trend over a period of time.
The fluctuation may 2 cyclical in nature to give rise to climatic cycles. Over a long period of time, climatic fluctuations may be such that a shift in the type of climate over a given area occurs; we then say there is a change or climate change.
Apart from the ice ages during the Pre-Cambrian 560 million years ago, there was a Permian ice age, which occurred 210-240 million years ago, and a Pleistocene ice age, which occurred less than a million years.
Significant ice ages have occurred every 100,000 years termination period of 10,000 years. Minor ones have occurred over 20 to 30,000 years.
The last period from 7,000 to 5,000 years has been characterized by declining temperatures with very cold some 28,000 and 350 years ago.
The latter cold interval between 1550 and l850AD has been referred to as the little ice age. During this period vineyards disappeared from England and European glaciers grew.
It is generally believed that we are present through an interglacial period.
Since the advent of instrumental records, data have indicated a warming trend in The Hemisphere from the 1880s to the 1940s and a warming trend in the early 1950s in the Southern Hemisphere.
The warming trend in the Northern hemisphere terminate in the 1940s when cooling set in, but this cooling has been reversed part since the 1970s. Studies have shown that since the AD’ instrumental records, a serried of droughts has been recorded in parts of the world.
In West Africa, for instance, major d occurred in 1913-14,1943-46,1972-74,1982-83 and 1987. Severe droughts were experienced in the United States in 1993 -94, in the 1930s and 1975.
The major cause of drought in this part tropics and indeed elsewhere is the failure of the seasonal monsoon rains.
Variability of Climate Over Time
To understand why climate varies, we have to examine the mechanisms that give rise to climate.
The climate depends on the general circulation of the atmosphere, which is determined by a complexity of factors and processes that constitute the global system.
The global climatic system includes the atmosphere, the hydrosphere (water biosphere (Living organisms), the lithosphere (land), and the cryosphere (ice and snow) and they interact with one another by the influence of solar energy.
Read Also: What’s New in Environmental Science
He observed that the climatic sta1 place at any given period is determined by three crucial factors are: The amount of solar energy received by the climatic s depends on the solar output, the extent of radiation in space before reaching the earth’s atmosphere, the dist, of the earth from the sun, and the angle of tilt of the earth’s rotation.
The way this energy is distributed and absorbed over the surface depends on the earth’s atmospheric composition, its topography, the extent of ice and snow cover, and the distribution of continents and oceans.
The nature of the interaction processes between the comp making up the global climatic system.