eChapters

Abstract

Climate change is the biggest problem of today, resulting in thawing glaciers, changes in crop yield, and disturbances of water resources not only in India but in the entire world. Crop yield were predicted according mid century (2050s) by using IPCC Scenario A2 and studied impact of climate change. Out of 80 districts of Uttar Pradesh the three were selected for the case study areas namely Meerut, Kanpur and Hamirpur. FAO based model ET₀ Calculator 3.1 and Aquacrop 3.1 Plus were used to estimate reference evapotranspiration and crop yields respectively by using two major food crops rice and wheat. Crop yield were estimated the present climatic conditions (2005) and mid-century condition (2050s). According to the comparison of simulation results for present and future scenarios, crop yield of rice and wheat was predicted to increase in the mid- century (2050s). However, food security was predicted to become a threat in future, because the increase in population till the 2050s is projected, and yield was increases in the major food crops. In order to sustain the growing population, there would be required in the future, a large area for growing rice and wheat in comparison to the area presently, to meet the same food availability per capita. Hence, there would be a need to increase the production of the food crops in order to meet the growing demands of food in the study areas.

Keywords: Crop yield, Global warming, Future, Production

Abstract

Cultivation of cash crops of good quality potent to give good economic returns depends largely upon adoption of modern practices in agriculture. The region under test consideration is completely irrigated and cultivates mostly the crops of grapes and sugarcane. A field testing that was carried out for the pumps used by local farmers, revealed glaring inefficiency in pump operation. This is attributed to numerous reasons, the standout of them-being improper pump selection and deviation from operating point. Survey of the farming pattern helped to establish nexus between the energy usages per acre for the two crops. Carbon Footprint was determined for the electricity utilized in these farms. Adoption of selection methodologies and efficient practices would lead to considerable saving in electrical power consumption. The impact of adoption of efficient practices was therefore quantified.

Keywords: Agriculture, Carbon Footprint, Pumps

Introduction

Biomass is a major source of energy in developing countries, particularly in India. Biomass as a fuel used in residential sector of India is a major component of total energy use in India. Type of fuels used in residential sector in India varies with locations and availability of the local fuels and also by way of cooking food in the open fires or in the rural cook stoves (Earthen Chulhas). The majority of the household in the rural sector of the developing countries burns the biomass fuel under traditional open stoves or in advanced closed cook stove (Fullerton et al., 2008). Biomass fuel includes any material of plant or animal origin, which is deliberately burnt by the human being. Approximately, 2 billion people in the developing world use the biomass fuel as the major source of domestic energy (Balakrishnan et al., 2002). Out of residential fuels, 80-90% of the energy requirement in rural India are met with the use of biomass in the form of fuel wood, dung cakes, charcoal and agricultural residue (TEDDY, 2007). Burning of biomass from all these sources is well known to be associated with the emission of smoke/plumes consisting of particulate and gaseous species as these are not energy efficient processes and thus the fuels are not burnt completely. The species emitted and their concentrations depend on the nature of the source of biomass and other factors including the physical parameters associated with the consumption of the biomass. The fate of the initial fire emissions depends strongly on both their composition and the regional state of the atmosphere. Once airborne, the particles begin to grow slightly in size as they age through condensation and coagulation. Despite their high concentrations and widespread distribution in the atmosphere, the sources remain poorly characterized. Biomass burning has drawn global concerns in the past decades for its effects on visibility, human health and global climate by emitting particulate matter (PM) and other gaseous pollutants (Andreae et al., 2005). Biomass burning emits significant global source of PM emissions to the troposphere which leads to deleterious impact on the earth’s atmosphere. It has an impact on the chemical composition of the atmosphere, the formation of photo oxidants and thus on air quality on a regional scale and climate change (Andreae et al., 2005). They also have harmful impact on human health, natural environment and ecological system (Cheng et al., 2000). The various impacts of these emissions have been well studied by Cheng et al. (2000) and Bardouki et al. (2003). Interest in this topic grew when several studies suggested that biomass burning emissions could rival fossil fuel emissions (Crutzen and Andreae, 1990). Biomass burning has received considerable interest (Bowman et al., 2009).

Abstract

Continental erosion and fluvial transport play an important role enhancing mobilization of organic carbon from soils and transferring this pool to the ocean through downstream rivers and streams. The Ganges-Brahmaputra river system represents one of the largest transporters of terrestrial carbon to ocean. Intensive agriculture in the Ganges basin coupled with atmospheric deposition (AD) of nitrogen may render the soil more prone to erosion loss of carbon and nutrients. The aims of this study were to quantify atmospheric deposition of nitrogen (AD-N) in the watershed and to assess the influence of land use and AD-N on carbon and nitrogen transport in Ganga River. We collected samples in summer low flow along a 1595 km long transect of the river to assess the status of DOC under variable land use and AD-N input and, at monthly intervals along a 35 km long transect to understand seasonal patterns and the influence of local control. Our study shows average deposition of reactive-N (NO₃^- + NH₄⁺) range from 19.7 kg ha^-1yr-1 in upper stretch to 38.6 kg ha-1yr-1 in the middle stretch. The AD-N in lower stretch was almost similar to the values recorded in the middle stretch of the watershed. The average concentrations of dissolved organic carbon (DOC) and dissolved inorganic nitrogen (DIN) in the river range from 0.62 to 5.3 mg L-1 and 52.0 to 385.6 µg L-1 respectively. The land-derived carbon and nitrogen emerging in surface runoff showed positive correlation with AD-N and the river DOC showed synchrony with land use, AD-N and autochthonous carbon pool. Our data indicate that DOC in Ganga River is rising and the land use together with AD-N is an important driver of rising DOC. We suggest that future climate model should consider large scale regional time series data on changing state of atmosphere-land-water coupling and associated shifts in carbon and nutrient transport of major rivers. This has relevance predicting region specific climate change drivers and preparing action plan for integrated river basin management (IRBM).

Summary

Water security can be defined as reliable availability of water in sufficient quantity and quality to sustain human health, livelihoods, food (agriculture, fisheries and aquaculture) and the environment (biodiversity and ecosystems). Discharge of chemical and biological pollutants (from agriculture, industry and domestic uses) into rivers and development of engineering infrastructure such as dams and weirs over rivers have modified river ecosystems threatening the global water security, water quality and water dependent biodiversity. Climate change (increase in the intensity and frequency of floods, droughts, bushfire and sea-level rise, ocean acidification, etc.) is an additional stress on water security. There is a need to reduce climate change impacts on water security which can be done via adaptations to climate change. Adaptation is adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities. In other words, the adaptation can be considered as, tackling the effects of climate change. Adaptation to climate change in terms of sustainable use of water may include increasing water availability by developing hydro-basins and transferring water from areas in which it is abundant to areas in which there is scarcity, the reduction of water losses, increasing storage capacity by building reservoirs and dams, rainwater harvesting, improvement of water use efficiency, desalination of seawater, water savings (leakage management, metering, retrofitting existing homes with water efficient products in toilets, showers, baths, using energy efficient dishwashers and washing machines), mandatory rainwater tanks in new and old buildings (for toilet flushing, washing clothes, gardens, car washing), use of recycled or reclaimed water for landscape irrigation or to recharge groundwater aquifers, and to meet commercial and industrial water needs.

Summary

Biodiversity (the variety of living things) is fundamental to ecosystem structures and functions, and provide the broad spectrum of goods and services that humans derive from natural systems such as food (e.g. fish), protection from disasters such as cyclones, storms, floods (e.g. mangroves) or maintenance of water quality. Species (biodiversity) respond to climate change either staying or moving out or dying out. For example, the rise of temperature as a consequence of climate change may cause some species to (a) stay in the same environment since they can tolerate to adapt to changes; or (b) may cause some species to move out in a suitable environment (e.g. some species to move pole ward, some up in elevation) or (c) some species (fish) to go deep to increased depths in the oceans to escape heat or warming or (d) may cause some species to die out or get extinct (species with restricted distribution, longer generation time will not be able to migrate or adapt to climate change). A pattern of range shifts such as pole wards and upwards has been documented in hundreds of species of plants and animals and is one of the strongest signals of biotic changes from global warming. These shifts result from two processes: cold-edge expansion and warm-edge contraction. There is now abundant evidence for local extinctions from contractions at the warm edges of species’ ranges or warm edge contraction because the species may have already reached the limits of their climatic tolerance. Investigations conducted reveals that many terrestrial and aquatic species are shifting their geographic ranges in response to rapid changes in temperature and precipitation regimes. For example, many terrestrial organisms are currently shifting in latitude or elevation in response to changing climate. It has been estimated that plants and animals have recently shifted to higher elevations at a median rate of 11.0 m per decade, and to higher latitudes at a median rate of 16.9 km per decade.

Summary

Climate change (floods, droughts, rise of temperature and sea level) can directly impact the incidence of water related diseases through effects on water temperature and precipitation frequency and intensity. This chapter focuses on some common water quality related diseases that may enhance due to climate change such as arsenicosis, cholera, cyanobacterial toxins, dengue, diarrhoea and malaria. Arsenicosis is the disease caused by arsenic (As) contamination. As poisoning via groundwater has become a worldwide problem with 21 countries experiencing As groundwater contamination including Bangladesh, India, and China. In Bangladesh, out of 64 districts, As levels in 60 districts have exceeded WHO recommended guidelines of 10 µg/L and in 51 districts it exceeded Bangladesh recommended guidelines of above 50 µg/L. Chronic exposure to As has been linked to carcinogenic effects in both humans and animals. These include cancer of the various skins and internal organs (lung, bladder, liver and kidney) and reproductive and developmental effects; cardiovascular disease; reduced intellectual function in children and mortality. Alternate floods and droughts (due to climate change) have been found associated with the release of As and contamination of groundwater in Bangladesh, therefore may increase the risks of the disease due to rise of extreme events such as floods and droughts. Cholera is a diarrhoeal disease caused by the bacterium Vibrio cholerae. In 2012, WHO reported 245, 3931 cases of cholera in 48 countries, with more than 3,034 deaths with a case-fatality rate (CFR) of 1.2%. The highest cases were from Africa, followed by Latin America and Asia. The epidemic of cholera is reported to be linked strongly with climate change. Changes in temperature, salinity, rainfall and abundance of phytoplankton have been shown to cause an impact on distribution and survival of V. cholerae. In Bangladesh, cholera (cholera-toxin producing strain of V. cholerae) outbreaks are related to plankton blooms and rise of sea temperature.

Summary

Climate change can affect the quantitative and qualitative status of water resources by altering hydrological cycles, systems and through changes of water quality via chemical and biological contamination. Changes in these variables lead to impacts on all the socio-economic and environmental goods and services that depend on these variables directly or indirectly including water supply, damage to ecosystems, water dependent food production. The most dominant climate drivers for water quantity or water availability are precipitation, run-off and river flows, floods, droughts, snows, glaciers, sea level rise etc. The observed climate change related impacts on world’s water resources/water quantity include increased precipitation at high latitudes and temperate areas and decreasing trends at low latitudes. The annual run-off in some regions may experience increased run-off, such as in high latitudes and large parts of the USA, whereas there has been a decrease in run-off such as parts of West Africa, southern Europe and southernmost of South America. Floods have been the most reported natural disaster events in Africa, Asia and Europe than all other natural disasters and in case of Bangladesh, six extreme floods have occurred in the last two decades. More intense droughts have been reported from Australia, semi-arid and semi-humid regions, western USA and southern Canada, the Sahel. Precipitation is projected to increase at mid- and high latitudes, in the tropics, whereas precipitation is projected to decrease over many sub-tropical areas (North Africa, northern Sahara), tropical Central American (Caribbean) and the Mediterranean. In areas where evaporation rates are expected to increase it would lead to reduced river and stream run-off. In contrast, areas receiving higher precipitation would likely have higher lake and river levels and may experience floods. The annual stream flow in the Murray-Darling basin (Australia) is projected to fall by 10-25% by 2050 and 16-48% by 2100 which would have severe consequences on irrigated agriculture in the region. Rivers depending on the Himalayan glaciers such as the Indus, Ganges, Brahmaputra, Syr Darya and Amu Darya could face water shortages or river run-off due to retreat of glaciers, and this would cause dramatic impact on drinking water supplies, biodiversity, hydropower, industry, agriculture and ecosystems on which about 2.4 billion people in Asia depends. Globally, ground water is the source of one third of all freshwater withdrawals, supplying an estimated 36%, 42% and 27% of the water used for domestic, agricultural and industrial purposes, respectively. The demand for groundwater is likely to increase due to global increase of water use for irrigation and a decline in surface water quality and reduced summer flows in snow-dominated basins. It is projected that climate change (drought, floods) will affect groundwater recharge rates (e.g. floods would increase recharge, drought would decrease recharge).

Summary

The main greenhouse gases (GHGs) that have caused the global climate change or global warming are carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). CO₂ is the principal anthropogenic GHG that affects the earth’s radiative balance. It is the reference gas against which other GHGs are measured and therefore has a Global Warming Potential (GWP) of 1. CH₄ and N₂O have a GWP of 21 and 310, respectively. CO₂ is responsible for most of the enhanced greenhouse effect of more than 50%, CH₄ for about 10-15% and N₂O for about 8%. The global atmospheric concentrations of CO₂, CH₄ and N₂O have increased since 1750. While CO₂ increased from a pre-industrial value of 280 ppm to 379 ppm in 2005, CH₄ increased from 715 ppb to 1774 ppb and N₂O increased from 270 ppb to 319 ppb during the same period. Rich countries and large developing countries account for most of global CO₂ emissions (China 23.5%, USA 18.27%, India 5.83%, Russia 5.72%, Japan 4.04% and European Union 13.98%). A new climate agreement called ‘Warsaw International mechanisms (November 2013) on loss and damage’ agreed to help the poor countries to cope with loss and damage from heatwaves, droughts, floods, typhoons, desertification and rising sea levels. The Warsaw agreement also includes a set of decisions to help developing countries to reduce GHG emissions from deforestation and degradation of forests which is backed by pledges of US$280 million financing by the United States, Norway and the United Kingdom. Projections for global average temperature rise is in the range of 1.1-6.4°C; a doubling of CO₂ (from pre-industrial 280 ppm) and average sea level rise is in the range of 0.18-0.59 m (Meehel et al. 2007) and 0.5–2.4 m (Brown et al. 2013). Hot extremes, heat waves and heavy precipitation events will continue to become more frequent. Projected data show that there is an increasing global trend in the rise of average temperature in all countries, regions or sub-zones; a decreasing trend in average precipitation in most sub-tropical areas and an increasing trend of precipitation in most of the tropical and high latitudes.

The communication system provides the forecaster with a large mass of figures; the next step is to put them into a suitable form for study. This is done by plotting the observations on a large outline map which in popular term is called a “Weather map” technically a “Synoptic chart” simplified synoptic charts appear in some newspaper.

A chart or map on which meteorological data presented and analysed is called a synoptic chart. Synoptic means having the same view point. The representation of the meteorological data in synoptic chart are atmospheric wind, temperature, pressure, cloud, precipitation, dew point etc., over a long area at a given local standard times.

Naturally Greenhouse gases are cover as blanket on the Earth and kept it about 33⁰C warmer than it would be without these gases in the atmosphere. This is called as the “Greenhouse Effect”.

Over the past century, the Earth has increased in temperature by about 0.5⁰C and many scientists believe that this is because of an increase in concentration of the main greenhouse gases viz., carbon dioxide, methane, nitrous oxide and fluorocarbons. People are now calling this climate change over the past century the beginning of “Global Warming”.

The earth has two motions. (1) Rotation and (2) Revolution. The earth rotates about its axis (west to eastward) with a speed of 464 m/s or 1669 km/hr. Its angular speed of rotation is about 7.29 x 10^-5 radians/sec or 0.26244 radians per hour. This rotation causes day and night and diurnal variations of weather.

The rotating earth revolves round the sun in an elliptical orbit (with the sun at one of its Foci) with a speed (orbital speed) of about 1.073 x 10⁵ km/hr or 29770 m/s or 29.8 km/s. This revolution causes seasons. It has been stated earlier that the apparent path of the sun with respect to the celestial sphere is called ecliptic.

Crop yield is influenced by genetical (heredity), external (environmental) and management factors that occur during the crop growing period. The external environment is the climate which regulates and determines the growth and development and final output of crop plants. But, man has no control over weather, hence it is dominance over the success or failure of agricultural enterprises. According to the World Meteorological Organization, the weather induced variability in crop yield is as high as 50 per cent. Therefore, weather should be taken as one of the inputs in agricultural planning.

Variation in field crops between years is associated with many factors. This is mainly due to weather, soil and management factors. There is complex reaction of weather variables among themselves as well as with other factors. Therefore, many attempts were made to study the effect of weather variable on crop yield through simulation modeling.

Environment in which crops are grown dictates their final yield. Of these environmental factors, climate and weather the uncontrolable factors, have maximum influence on crop productivity. Vagaries of weather subject a crop to different ecological situations from year to year leading to differential responses of crops to input resources. This situation limits the use of costly inputs for realizing optimum yield. While weather itself cannot modify, the hazardous weather can often be mitigated by agronomic management. Therefore, the primary requirement for initiating agronomic measures against weather hazards is foreknowledge of weather situation that is likely to develop in an area.

Climate, in general, is the totality of weather during a longer period and over wider area. Agro climate can be defined as the conditions and effects of varying weather parameters like solar radiation, rainfall etc., on crop growth and production.

Climatic classification is a method of arranging various data of climatic parameters to demarcate a country or region into homogenous zones i.e., places having similar conditions.

Season is a period in a year, comprising few months during which the prevailing climate does not vary much. Growing season for a crop is more important for its yield and other management practices, to be followed.

Indian Meteorological Department has divided the year into four seasons.

Plant growth is resultant of all the environmental factors – climatic, physiographic, edaphic and biotic factors.

For a particular field – it is primarily a function of climate with temperature and light – being the most important factors. – Close relationship exists between plant phenology and both latitude and altitude.

The Sun is the primary source of heat to the Earth and its atmosphere. The heat received from other celestial bodies as well as the interior of the Earth is rather too significant. The distance that separates the Earth from the Sun is about 149.0 million km. The diameter of the Sun measures roughly about 1.3824 million km. The surface temperature of the Sun is estimated between 5500^o C and 6100^o C. (or 5762^o K).

The weight of the sun is about 1.9 X 10 30kg. The radius is 6.97 X 10 8 m or the diameter of the sun is 14 X 10 5 km. The mass of the earth is 6 X 10 24 kg, the radius is 6.4 X 10 6 m. The gravitational force of the earth is 9.81m/s². Whereas the sun‘s attractive force is 274m/s². This is 25 times higher than earth’s gravitational force.

El Nino means ‘The Little One’ or ‘Christ Child’ in Spanish. It was originally recognized by fisherman of the coast of South America as the appearance of usually warm water in the Pacific Ocean, occurring near the beginning of the year i.e. around Christmas. That is why the name is used. El Nino, the periodic warming of Pacific Ocean waters that affects the weather worldwide. C. Fred and T. Andrus of the University of Georgia studied the ancient fish bones from refuse left about 6000 years ago by ancient peoples in Peru and found that ocean catfish lived in water that averaged 60 to 70 warmer than now and that there was little variation in temperature. He concluded that if El Nino was occurring at the modern rate, once every two to seven years, then the bones from the fish would have reflected the temperature variation.

The march of weather factors during crop period is never smooth and regular. Agriculture, because of its dependance on climate is inevitably subjected to unpredictable long and short term fluctuation characteristic of atmosphere conditions. Climate introduces an element of risk in farming which makes it particularly hazardous occupation.

A Weather hazard in this context can be defined as any type of extreme weather condition that can damage the crops and animals leading to abnormal decrease in production and income. The extent to which these hazards create risk depends on the time of occurrence, intensity and duration of the hazard besides the age, stage of development and inherent resistance of the crop or livestock involved. Major abnormalities affecting the crop production are:

Cloud usually consists of very small droplets of water which cannot fall appreciably below the cloud base without evaporation. In this condition clouds are stable. Rain drops are about a million times heavier than cloud drops and rain develops only if the cloud droplets grow by some mechanism. Cloud Seeding mechanism depends on the difference in vapour pressure over ice and super cooled cloud, water evaporates of the droplets and migrate to the ice crystal, which grows and begins to fall increasing their growth rate by coalescence with other droplets and eventually melting and falling as rain drops. Presence of ice nuclei determines whether ice crystals form in a supercoold cloud or not. Ice crystals form on naturally occurring nuclei at temperatures of – 10⁰ to 30⁰ C. At warmer temperatures, either the efficient ice-forming nuclei are often deficient in the atmosphere or the cloud may occur with tops supercooled but not to an extent which activates the ice nuclei available. It should be possible to initiate precipitation by introducing ice crystals or by supplying artificial nuclei.

The change of state of water from solid and liquid to the vapour and its diffusion into the atmosphere is referred as Evaporation. In the meteorology, evaporation is defined as the maximum possible loss of moisture from a wet, horizontal, flat surface exposed to weather which exist in the vicinity of plants.

FACTORS AFFECTING EVAPORATION

1. Those affecting water supply at the evaporating surface. i.e., soil and plants including soil storage capacity, rainfall and irrigation and

2. Those affecting energy supply to the evaporating surface like solar radiation.

Hydrological cycle involves four major steps, Viz., Evaporation, Transpiration, Condensation and Precipitation. Though the cycle has neither a beginning nor an end, the concept of cycle begins with the water of oceans, since it occur nearly ¾ of the Earth’s surface. Radiation from the Sun, evaporates water as water vapour from the oceans into the atmosphere. The water vapour rises and collects to form clouds. Under certain condition, the cloud moisture condenses and falls back to the Earth as rain, snow, hail etc. Precipitation reaching the Earth surface may be intercepted by vegetation or enter into the soil, may flow as run-off or may evaporate.

Evaporation may be from the surface of the ground or from free water surface. Transpiration may be from plants.

Condensation: The physical process by which a vapour becomes a liquid or solid – opposite of evaporation.

Cloud has been defined as a visible aggregation of minute water droplets and / or ice particles in the air, usually above the ground level.

CLASSIFICATION OF CLOUDS

Though confusion apparently arises from the number of kinds or species, the genera seems reasonably clear out, if we are able to recognize their main characteristics.

Clouds are usually classified according to their height and appearance. For convenience, we list them in descending order. High clouds, middle clouds and low clouds are some forms do not fit in any of these categories. But fortunately their particular characteristics make them easily identifiable as vertical development clouds. We must exercise some caution in studying on height. There is some seasonal as well as latitudinal variation and there is some overlapping from time to time. However, the appearance of clouds is quite distinctive for each height category.

Air Constantly moves from place to place due to pressure differences which are caused by difference in temperature.

Wind has been defined as air in horizontal motion. According to Byers, “The wind is simply air in motion, usually measured only in its horizontal component”. According to Trewaitha, “Wind is simply air moving in a direction which is essentially parallel with the Earth’s surface.

There are two types of movement of wind in the atmosphere.

1. Horizontal movement

2. Vertical movement (Currents)

The primary wind circulation in Northern and Southern hemispheres is seen in figure on page 51.

Moisture present in the atmosphere plays a significant role in weather and climate of the region. There are three major components in the atmospheric moisture.

  I. Humidity

 II. Precipitation

III. Evaporation.

Humidity: The terminology related to humidity and concerned with gaseous form of water i.e. water vapour, several expressions of the amount of water vapour in the air is used. They are as follows.

The atmospheric pressure is weight of the air which lies vertically above an unit area centered at a point. Normal pressure of air is 1.034/cm².

Pressure is defined as the force per unit area.
At the surface of the earth the atmosphere air exerts a pressure of about 10⁵ Newtons/m² or 10⁵ Pascals, which is called one bar or one atmosphere. Evangelista Torricelli (1608-1647) devised a method for measuring the atmospheric pressure by mercury (Hg) barameter in 1643.

In climatology, terms “Weather” and “Climate” have different connotations. Weather refers to the state of atmosphere at any given time denoting the short- term variations of atmosphere in terms of temperature, pressure, wind, moisture, cloudiness, precipitation and visibility. Weather is highly variable. It is constantly changing, sometimes from hour to hour and at other times from day to day. The aforementioned properties of the atmosphere are subject to constant change and their state at any time determines the state of the weather. However, weather elements are not separate rather they are closely related with each other.

David I. Blumenstock, an eminent climatologist has defined the weather in more restrictive sense. According to him, weather is the behaviour of the lower atmosphere with particular emphasis on the atmospheric behaviour which affect the lands and oceans and have a marked influence on the organisms that live upon the lands, within the waters of the earth or in the lower air. For the geographer, this definition of weather is more satisfactory. Since, he is interested more in the working of the lower atmosphere which affects the life of man as well as natural environment directly. Thus, we come across a great many varieties of weather covering a wide range of conditions.

Geological evidence suggests that the age of the earth is about 4,50,00,00,000 (4.5 billion) years and life began on earth between 0.6 to 1.0 billion years after earth has formed. That is life began on earth some where 4 to 3.5 billion years ago.
The plant kingdom over the globe produce oxygen about 30,00,00,000 (3 million) kg per second which is consumed by the living beings on the earth. Air which is present in the atmosphere is a mechanical mixture of gases. The various gases, solid and liquid particles in the air that envelope the earth are bound to it by the gravitational attraction. This complex content of gases, solid and liquid particles is called atmosphere. The atmosphere extends above the surface of the earth to great heights. There is no sharp boundary between the atmosphere and the outer space. For our convenience, the height of the atmosphere is taken as 1000 km. The lowest one km which is called planetary boundary layer, contains 10 per cent of the mass of the atmosphere. All biological and human activities are confined to this planetary boundary level. The mass of the atmosphere is about 5.6 x 1018 kg (mass of earth is 6 x 1024 kg). The mass of the oceans water is about 1.4 x 1021 kg. This shows that the mass of the oceans is more than 250 times the mass of the atmosphere. The density of the dry air at the earth surface is 1.225 kg/m3 and at an altitude of 5.5 km this drops to 0.66 kg/m3 and at 30 km altitude it is about 0.013 kg/m3.

Food, clothing and housing are the three basic needs of a man. After that the additional requirement of a man are personal health and happiness. These can be considered as human factors. The material factors are agriculture, industry, trade, water resources management, insurance.

The continuous increase in population made the planners, researchers and cultivators to increase the food production to feed all the people. So, the second green revolution has to follow. Due to increase in air temperature and climate change, the cultivation practices to change based on the changing climatic condition. The study of climate is not only necessary for food production, but also needed for transportation, storage, value addition and consumption.

The need of the cloth for man is not only for style. The basic need is to protecting the human body from the climatic factors like heat and cold. Clothing must provide to maintain the body heat at about 37^oC. Clothing must be made based on the local climatic condition. So, the traditional fiber for making the cloth is better for health.

Housing provides the internal controlled climate to the human being. It provides comfort to the inhabitants. Like clothing traditional styles, sites and methods of housing have to be followed based on the climatic condition. Though people are living in the multi-storied building, they have to concentrate on comfort in the case of sufficient aeration and ventilation. In India, the Vastu Sastrum is nothing, but it provides the needs of the human livings for their comfort with sufficient light and air.

The climatic factors for a particular day are not similar to previous day. Similarly, definitely the climate of one season is not similar to other season. Man needs some recreation in the comfort climatic areas. So, he/she needs cool climate for stay that necessitate to air conditioner particularly during summer.