eChapters

Key facts

    
•    Though water is the most widely occurring substance on earth, freshwater accounts for only 2.5% whereas the rest of water is saltwater. The agriculture sector uses more than 75% of freshwater available. 
    
•    The current observed climate change impacts on water resources include increased precipitation at high latitudes and temperate areas, decreasing precipitation at low latitudes; decreasing snow covers, and glaciers in most regions; decreasing flows in some river basins; floods and droughts in some countries and significant decreases in lake and river size in Africa.
    
•    A number of climate models projected that a doubling of atmospheric concentrations of CO₂ would increase global precipitation by at least 5%.  The precipitation is expected to increase in some areas, such as, at high latitudes and in the tropics (south east monsoon regions and over the tropical Pacific), whereas the precipitation is likely to decrease in the sub-tropics (e.g. much of North Africa and northern Sahara).

Key Facts
    
•    The United Nations Framework Convention on Climate Change (UNFCCC) defines ‘climate change’ as a ‘Change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods’.
    
•    The main green house gases (GHG) that have caused the global climate change or global warming are carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (NO₂).
    
•    CO₂ is the principal anthropogenic greenhouse gas that affects the Earths 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 green house effect of more than 50%, CH4 about 10 to 15% and NO2 about 4%.
    
•    The global atmospheric concentrations of carbon-dioxide, methane and nitrous oxide have increased since 1750, CO₂ increased from a pre-industrial value of 280 ppm to 379 ppm in 2005, CH₄ increased from 715 ppb to 1774 ppb and NO₂ increased from 270 ppb to 319 ppb in 2005.

Key facts
        
Agriculture and livestock
    
·    The Intergovernmental Panel on Climate Change (IPCC) defines adaptation as ‘adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities’. The adaptation can be considered as tackling the effects of climate change, whereas mitigation is tackling the cause of climate change such as reducing the sources or enhancing the sinks of greenhouse gases. There could be different types of adaptation such as autonomous (spontaneous) and planned adaptation (policy decision).
    
·    Autonomous adaptation includes altering varieties and/or species those are more appropriate to the altered thermal regime or with increased resistance to heat shock and drought; altering the timing or location of cropping activities; altering fertilizer rates to maintain grain or fruit quality consistent with the climate and altering amounts and timing of irrigation and other water management practices; diversifying income by integrating other farming activities such as livestock raising, integrated agriculture and aquaculture/fish farming; development and use of varieties and species resistant to pests and diseases, wider use of technologies to ‘harvest’ water, conserve soil moisture (e.g. crop residue retention) and to use water more effectively in areas where rainfall is projected to decrease and using seasonal climate forecasting to reduce production risk.

Key facts
    
·    The Food and Agriculture Organization (FAO) defines food security as a ’situation that exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life’. There are four dimensions of food security: Food Availability (availability of sufficient food for all people at all times, i.e. production); Food Accessibility (physical and economic access to food at all times, i.e. affordability), Food Utilization (access to food that is nutritious, safe and produced in environmentally sustainable ways, i.e. nutrients in food and food safety); and Food Stability (reliability of adequate food supply).
    
·    Agriculture is important for food security since it provides food for the people and is the primary source of livelihood for 36% of the world’s total workforce. In the heavily populated countries such as Asia and the Pacific, about 40% to 50%, and in sub-Saharan Africa, about two-thirds of the working population make their living from agriculture.
    
·    Agriculture, livestock and fisheries production are all sensitive to climate and are affected by its changes. Climate change will increase hunger and malnutrition, emergence of new pests and diseases and will threaten fishing and aquaculture industries.

Key Facts
        
Agricultural food
    
·    There are multiple pathways through which climate-related factors may impact food contamination and food safety, food quality, foodborne diseases including changes in temperature and precipitation patterns, increased frequency and intensity of extreme weather events, ocean warming and acidification and changes in the transport pathways of complex contaminants.
    
·    All or most foodborne pathogens and their associated diseases are linked to changing environmental conditions, the notable of which are campylobacteriosis, salmonellosis and vibriosis.
    
·    An estimated 30% of reported cases of salmonellosis across much of continental Europe have been attributed to warm temperatures, especially when they exceed a threshold of 6°C above average. Likewise both in Australia and Canada a positive correlation was found between increasing temperature and incidence of salmonellosis.
    
·    Zoonosis such as Rift Valley Fever (RVF), West Nile Fever, tick-borne diseases and non-zoonotic animal diseases such as Blue tongue, African horse sickness, African swine fever are examples of animal diseases whose distribution is expected to be strongly influenced by climate change and variability.
    
·    Mycotoxin is a toxic secondary metabolite produced by filamentous fungi, commonly known as moulds and may contaminate agricultural commodities (food) by growing on them both before and after harvest, whenever the humidity and temperature are permissive. The most prominent mycotoxins are aflatoxins, deoxynivalenol, zearalenone, ochratoxin-A, fumonisin, and patulin.
    
·    The humans ingestion of mycotoxins occur through consumption of the mycotoxin contaminated plant-based foods, such as grains, maize, barley, rice, coffee, nuts and their residues, and metabolites in animal-derived foods, for example aflatoxin M1 (AFM1) in milk and meat products. In addition, mycotoxins may occur in beer and wine.

Key facts

Agriculture
    
·    Agriculture production (plant growth) is highly dependent on climate since crop growth is influenced by solar radiation, temperature and precipitation and sensitive to climate variability and weather extremes (droughts, floods, severe storms).
    
·    Climate change is projected to have an effect on local agriculture and the net result could be harmful (e.g. frequent droughts, salinization of agriculture land due to sea level rise) or beneficial, (e.g. enhance CO₂ and higher yield, longer growing season, increased precipitation) or mixed.
    
·    Climate change or a doubling of GHGs (2 x CO₂) is projected to cause both gains and losses of agriculture land.
    
·    Each crop has a specific temperature range at which vegetative and reproductive growth will proceed at the optimal rate and exposures to extreme temperatures during these phases can impact growth and yield. Higher temperatures during the reproductive stage of development can affect pollen viability, fertilization and grain or fruit formation. 
    
·    Warming generally allow plants to grow faster that are below their optimum temperature, however for cereal crops faster growth means there is less time for the grain itself to grow and mature, reducing yields. 
    
·    Night-time temperatures are rising faster than daytime temperatures and are expected to continue rise in the future. According to International Rice Research Institute (IRRI), Philippines, the rise of night time temperature decreases rice yield by 10% for each 1°C increase in growing-season night time temperature in the dry season.

Key Facts
    
·    The United Nations Framework Convention on Climate Change (UNFCCC) defines ‘climate change’ as a ‘Change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over the comparable time periods’.
    
·    The main green house 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 green house 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.

5.1    Population Growth
    
5.2    Exponential Growth
    
5.3    Population Explosions
    
5.4    Over Population
    
5.5     The Causes of Rapid Population Growth
    
5.6    Ways and Means to Solve Over Population
    
5.7    Environment and Health
    
5.8    Family Welfare Programme
    
5.9    Human Rights
    
5.10    Child Welfare
    
5.11    Women Welfare

4.1    Urban Issues
    
4.2    Environmental Ethics - Issues and Possible Solutions
    
4.3    Water Conservation
    4.3.1 Rainwater Harvesting
    
4.4    Greenhouse Gases and their Sources
    4.4.1 Climate Change
    4.4.2 Global Warming
    4.4.3 The Greenhouse Effect
    4.4.4 Consequences of the Greenhouse Effect
    4.4.5 Acid Rain, 176
    
4.5    Ozone Layer Depletion
    
4.6    Nuclear Accidents
    
4.7    Waste Reclamation
    
4.8    Consumerism and Waste
    
4.9    Forest (Conservation) Act 1980
    
4.10    Wildlife Protection Act
    
4.11    The Air  (Prevention and Control of Pollution) Act 1981
    
4.12    Water (Prevention and Control of Pollution) Act 1974
    4.13    The Environment (Protection) Act, 1986
    4.14    Environmental  Laws

3.1    Air Pollution
    3.1.1 Classification of Air Pollutants
    3.1.2  Properties of Air Pollutants
    3.1.3  Health Effects
    3.1.4 Particulate Pollution Control Equipments
    3.1.5 Gaseous Pollution Control Equipments
    
3.2    Water Pollution
    3.2.1 Causes of Pollution
    3.2.2 Origin of Wastewater
    3.2.3 Waste Water Composition
    3.2.4 Types of Water Pollutants
    3.2.5 Basic Processes of Water Treatment
    
3.3    Land
    
3.4    Marine Pollution
    3.4.1 Sources and Effects of Marine Pollution Toxics
    3.4.2 Control Measures
    
3.5    Noise
    3.5.1 Effects of Noise
    3.5.2 Major Noise Sources
    3.5.3 Noise Control Measures
    
3.6    Thermal Pollution
    3.6.1 Effects of Thermal Pollution
    
3.7     Nuclear Hazards
    3.7.1 Nuclear Weapons
    3.7.2 Types of Nuclear Bursts
    3.7.3 Nuclear Injuries
    3.7.4 Residual Radiation
    
3.8    Nuclear Waste and their Treatment
    
3.9    Solid Waste Management
    3.9.1 Role of Human in Prevention of Pollution
    
3.10    Disaster Management
    3.10.1 Floods
    3.10.2 Earthquake
    3.10.3 Cyclone
    3.10.4 Landslides

2.1    Ecosystem
    2.1.1 Major Components of Ecosystems
    2.1.2 Energy and Matter Flow in Ecosystems
    2.1.3 Various Types of Ecosystems
    
2.2    Biodiversity
    2.2.1 Genetic Diversity
    2.2.2 Species Diversity
    2.2.3 Ecosystem Biodiversity
    2.2.4 Values of Biodiversity
    2.2.5 Threats of Biodiversity
    2.2.6 Endangered and Endemica Species of India
    2.2.7 Biodiversity Conservation

1.1     Forest Resources
    
1.2     Uses of Forest
    
1.3     Deforestation and its Effects
    
1.4     Water Resources
        
    1.4.1 Water Conflicts
    1.4.2 Dams Conflicts
    
1.5    Drought
    1.5.1 Regions of Drought in the World
    1.5.2 Effects of Drought
    
1.6     Flood
    
1.7    Environmental Effects of Mineral Resources
    
1.8    Food Rseources
    1.8.1 Technological Improvements in Food Production
    1.8.2 Environmental Issues Related to Increased Production
    
1.9    Overgrazing and its Effects
    
1.10    Impacts of Intensive Farming on Soil and Water Resources
    
1.11    Effects of Agricultural Chemicals on the Environment
    
1.12    Energy Sources
    
1.13    Waterlogging
    
1.14    Land Resources
    
1.15    Land Degradation
    
1.16    Soil Erosion
    1.16.1 Types of Erosion
    
1.17     Desertification
    1.17.1 Causes of Desertification
    1.17.2 Effects of Desertification
    
1.18    Conservation of Natural Resources
    1.18.1 Conflicts
    1.18.2 Challenges and Methods

ABSTRACT
It is impossible to envision a world without energy provisions and has become inevitable and an integral part of a nation’s prosperity. It has unparallel contributions towards the socioeconomic empowerment, industrial growth, and technological advancements, as also in mitigating greenhouse gas (GHG) emissions. Judicious utilisation of energy sources without infringing upon the sustainable energy demand is the need of the hour. Taking India’s huge bovine strength into account, biogas technology has the potential to transform the standard of living of rural millions. Effectively implementing the Govt. of India’s National Biogas and Organic Manure Programme (NBOMP) could save precocious demand on electricity, fertiliser and firewood while promoting self-sustainable organic farming. In this chapter, the cost and benefit analyses of biogas technology (involving biogas plants of different capacities) are discussed along with the long-term approach at the grassroots level to promote digested slurry for organic farming. The commercialisation and carbon crediting of biodigester technology is also narrated. It is necessary to chalk out a revenue model to commercialise slurry at the grassroots level to economically empower the beneficiaries, from family-type to industrial-scale biogas plants. Small-scale biofertiliser hubs at district level may be organised to collect dry slurry from the beneficiaries and process them further to make it market-ready through entities operating at the national level developing manure for agricultural practices, as also feeding materials for animal husbandry practices.

ABSTRACT
The ‘steel-drum type’ biogas plant installation programme in Punjab was initiated in the early seventies, whose construction works were entrusted on the Department of Agriculture. Because of their high cost and high failure rates then, only the affluent farmers could afford to install. In the meantime, a cheaper Chinese model, also known as Janta type (dome-type replacing the drum-type) plant, became popular but was still out of the reach of ordinary farmers. With dual objectives of cost reduction and efficient biogas production to make it affordable to small farmers, a coordinated research was initiated. Detailed extension surveys were carried out in Ludhiana district which inferred that the farmers did not install the gas-holding steel drum though they purchased it. A significantly low cost Katcha-Pucca plant model of 15m3/d capacity was developed and installed in Sangrur district. Similar digester was tried for Janta model in which the inlet, outlet and dome (gas holder) were masonry works but the digester was a Katcha pit, the dome of the plant being modified to a semi-circular dome. More than 80 such plants are functional in a single village, and more than 40–50% of the plants installed in Punjab and Haryana are these PAU designs. The chapter deals in greater details on the design aspects and the extensive field works carried out to achieve these successes, along with some relevant facts and figures. The write-up is written as a commentary, rather than a typical chapter, for the benefit and interest to the readers.

ABSTRACT
Nisargruna biogas technology has been developed in BARC for processing different types of biodegradable waste. This technology is based on biphasic separation of aerobic and anaerobic stages. Introduction of aerobic predigester has increased the efficiency of the process in terms of enhancing the quality and quantity of methane and also reducing the retention time of the process. Process parameters of the plant were studied and found that the modified design has proved very effective in faster digestion of complex waste. The technology has been commercialised and has spread across different parts of country for processing variety of wastes including kitchen waste, municipal waste, agriculture waste, textile waste and poultry waste. Microbial population from different stages of the plant was also studied and found their ability to convert waste to biogas, containing mainly methane.

Keywords: biogas, biphasic digestion, green energy, methane, microbial fermentation, Nisargruna, waste management

ABSTRACT
The global energy demand is increasing day by day. Now-a-days, the supply of global energy is highly dependent on fossil fuels (viz., crude oil, lignite, hard coal, natural gas). But, on one hand the source of fossil fuel is decreasing at a rapid rate, and on the other hand the burning of fossil fuel is also degrading the environment due to huge Greenhouse Gas (GHG) emission (FAO/CMS, 2011). Hence, there is an urgent need of an alternate clean energy source that can sustain the future development undeterred while still protecting the environment. Biomass is considered as a sustainable source of clean energy that is useful in steam, fuel and chemicals production. It can be digested in controlled environment to produce biogas. The biogas is a clean, non-polluting and smoke-free fuel (Weiland, 2010) which can be used for applications that include cooking, space cooling/refrigeration, heating, electricity generation and gaseous fuel (CNG) for vehicles (Weiland, 2003). This paper analyses possible alternatives to process and utilise biogas for energy at industrial scale as a petroleum fuels replacement.

ABSTRACT
The rapid industrialisation and speedy progress towards urbanisation across the world have created the huge demand for energy moreover creating enormous quantity of wastes. The latter is in charge for polluting the environment in an exponential manner, resulting out of the harmful and poisonous compounds released by them. In recent years, there has been a pattern change from ‘waste-to-wealth’, considering the value of high organic fraction accessible in the wastes. The best-accomplished methods are that of anaerobic digestion; contribute to the production of methane (CH₄). Similar biotransformation has partial net energy harvests. Recently, fermentation industries steering their interest towards the production of value added products, viz., biohydrogen (H₂), biopolymers, ethanol, vitamins, acetic acid, enzymes, butanediols, etc. from carbon rich organic waste like cellulosic substrates have been envisioned to flourish in a multi-step process, such as the ‘Biorefinery’. A contemporary development in fermentation technology holds the key to overcome the constraints for such processes that may lead to a sustainable economy. One related technology is electrofermentation that has attracted significant attention recently owing to its capacity to boost the metabolic activities of microbes by means of extracellular electron transfer.

ABSTRACT
Biomethanation is the process of generating energy from anaerobic digestion (AD) of organic refuse. This helps reduce dependency on fossil fuels while reducing CO₂ emission. Organically-rich kitchen refuse (KR) generated daily from the households all over the world could be a good candidate to biogasify, though the quantity and quality of biogas depends on the KR proximate. To enhance biogasification, KR is subjected to physical, chemical and/or biological pretreatment. Physical pretreatments include chopping, grinding, ultrasonication and steam explosion, whereas chemical pretreatments could be by an alkali or a base. Biological treatment involves digestion of the organic matters by individual microbe or its consortium, although it takes place naturally. For biological treatment, standardising the substrate and inoculum ratio is essential. Candidate strains must be mutually compatible to formulate a microbial consortium. Bacillius seems to be a potential candidate as it is a facultative anaerobe exhibiting multiple essential enzyme activities (viz., amylase, cellulase and lipase). Maintaining an optimal pH of 7.0 and temperature of 37°C before and during anaerobic digestion is suggested. Other important factors in digestion include organic loading rate, retention time, C/N ratio, volatile fatty acids (VFA) concentration, etc. VFA content is vital as its accumulation during acidogenesis adversely affects the AD by dropping pH values to unfavourable levels. Acetogens convert VFA to acetate, CO₂ and H₂ in acetogenesis, finally converting it to CH4 in methanogenesis. For effective methanation,

ABSTRACT
The annual accumulating organic wastes generated through milling, brewing and various other agro-industrial and agri-processing activities in India amount to about 500 MMT. Most of these contain three major structural biopolymers, viz., cellulose, hemicellulose and lignin, a large proportion of which is carbohydrate and phenolic in nature. Massive accumulations of this kind of recalcitrant biomass not only deteriorate the environment, but also generate huge amount of potentially useful materials. Biological transformation has globally become increasingly popular among researchers and academicians in treating agricultural, industrial, organic and toxic wastes these days. About 60% by weight of the original pineapple fruit in forms of peeled skin, core, crown end, etc. resulting from the pineapple processing remains unutilised being discharged as waste, causing disposal and pollution owes. Of the 10% dry matter content of such waste, about 96% is organic and 4% is inorganic. Being rich in cellulose and hemicellulose, it can be a valuable resource for numerous value-added products by bioconverting it to valuable products, including bioenergy. Biomethane is one such energy resource that can be produced by valorizing pineapple wastes by employing various bioconversion technologies. This chapter focuses on the bioconverstion technologies to produce biomethane from pineapple wastes.

ABSTRACT
There is a quantum global growth in both number and size of dairy industries in recent times. These industries discharge thousands of liters of wastewater characterised by a heavy chemical oxygen demand (COD), biological oxygen demand (BOD), nutrients, inorganic salts, besides detergents and sanitisers each day (Kushwaha et al., 2011). High carbohydrates, fats and proteins contents in such waste streams originating from milk pose challenge to conventional municipal sewage treatment systems (Demirel et al., 2005). The easily biodegradable dairy effluent leads to precipitation of casein which is toxic and has a strong odour. Without adequate treatment, these effluents could pose serious threats to the receiving water bodies and disturb the ecosystem (Satpathy et al., 2017). For such heavily loaded organic effluents, biogasification through anaerobic digestion seems a promising strategy. This cost-effective energy generation process is also effective in environmental management compared to its other eco-friendly renewable source counterparts, such as, hydro, solar and wind (Satpathy, 2017). The Upflow Anaerobic Sludge Blanket (UASB) reactors are the most popular anaerobic systems to treat the fluctuating organic loads in dairy effluents. Anaerobic filter (AF), Upflow Anaerobic Filter (UPAF), Fixed-bed anaerobic reactor, Anaerobic Hybrid Reactor (AHR) etc. are few other systems that are demonstrably competent removing COD upto 90% and generating biogas. Successful anaerobic systems reported yielded (with upto about 85% CH₄ content) 0.32-0.34m3 CH₄/kg COD removed. Biomethanation process and reactors designs are constantly being optimised for effective treatment of the effluents while maximising the biogas production. The energy-rich gas thus obtained could further be utilised for heat and electricity at the domestic level, and also as a vehicular fuel. Residual digestate can also be used as organic manures (Angelidaki et al., 2007).

ABSTRACT
Rice straw is one of the most abundant lignocellulosic agricultural wastes in India and can be used as a major resource for biogas production. The structure of rice straw is complex and is made up mainly of cellulose, hemicelluloses and lignin. The lignin physically shields the cellulose and hemicelluloses, the main components which can be converted to energy, and hinders the access of microbial enzymes to these carbohydrate moieties. To overcome this making the straw a potential resource of biogas production, effective pretreatment is necessary that can efficiently hydrolyse the straw and make it accessible to cellulolytic enzymes and methanogens. Various pretreatment methods which are employed currently in the market are discussed here. For a process to be economically feasible it is necessary that the pretreatment be efficient as well as cost effective. To gain some insights into this aspect, the techno-commercial feasibility of Biomethanation of rice straw has been discussed.

ABSTRACT
Recent challenges for fossil fuels, associated environmental issues with disposal of organic garbage, and the rising costs for energy has encouraged researchers to search for alternate energy sources. Massive uncontrolled biogas from landfills, sludge and organic material degradation under anoxic conditions is an environmental management issue. Methane emission to atmosphere has a tremendous green house effect, but this can also be a valuable renewable energy resource. Biogas from kitchen wastes through anaerobic digestion by methanogens is such an alternate technology. Kitchen wastes are considered one of the best raw materials for biogasification. Biogas is mainly composed of 50-74% methane (CH₄), 25-28% carbon-di-oxide (CO₂), other volatile compounds including hydrogen sulphide (H₂S), water vapour and other trace gas compounds. The impurities in it, like Hydrogen sulphide (H₂S) which is corrosive, downgrade its quality. Purified biogas of higher calorific value attracts attention as a substitute fuel for additional applications. Its purification using various suitable scalable and economically-viable scrubbing technologies to enhance its quality and performance as an alternate fuel is an important step in this direction. Thus, a technology to generate and purify biogas from kitchen waste has significant prospects in the energy sector, and also as a promising enterprise to employ the youth.

ABSTRACT
Increased environmental pollution and high demand over supply for conventional fossil fuel sources have led to the exploration of other renewable energy sources. Out of the potential alternatives, methane has come up with a promising unconventional fuel source. Several technologies have been developed to establish methanation, including biomethanation, chemical methanation and gas-to-liquid technology. Several factors like process parameters, catalysts and reactors have been studied for process optimisation and making methane production commercially viable. Although methane as a greenhouse gas is a contributor to global warming, its combustion produces relatively ‘environment friendly’ gas CO₂, and H₂O. The released CO₂ is fixed into biomass by plant through photosynthesis process. Only rarely does methane combustion produces CO when combusted in an oxygen-limited condition. Thus, methane production and combustion are carbon neutral process. This chapter focuses on the application of methane as a source of alternate energy. Various technologies used, recent advances and challenges faced in methanation process are discussed.

ABSTRACT
Biomethanation comprises of four interdependent stages in series, hydrolysis, acidogenesis, acetogenesis and methanogenesis. Methanogenesis, the final stage of biomethanation, is accompanied with the reduction of substrates that include organic acids such as CH₃COOH, and others such as CO₂ and CH₃OH to CH₄ by methanogenic and methanotrophic archaea, usually under anaerobic conditions. Strictly anaerobic methanogenic archaea are found in the ruminant intestine, sewage digester, groundwater and deep soil/water etc. In methanogenesis, H₂ acts as the electron donor while substrates CO₂, CH₃OH and probably CoM-S-S-CoB (for CH₃COOH) act as terminal electron acceptors and reduce to methane, a process known as anaerobic respiration. This conversion is associated with the electrogenic proton motive force along with sodium motive force to drive the ATP synthesis by A0A1 ATP synthase, known as respiratory phosphorylation. The mechanism of conversion of methane from CO₂ by methanogens with cytochromes is same as those without cytochromes except that the reduction of heterodisulphide CoM-S-S-CoB is performed by the membrane-bound VhoACG-HdrDE complex for former while by cytoplasmic MvhADG–HdrABC complex for the later.

ABSTRACT
Methanogenesis is an important biogeochemical process takes place in anaerobic ecological sites. It is the last step of terminal electron accepting process of anaerobic respiration. Methanogens synthesise CH₄ using acetate and CO₂ as precursor molecules. Former types of methanogens are referred as acetoclastic methanogens and the later ones as hydrogenotrophic methanogens. After biogenesis of CH₄, it is emitted to atmosphere and causes global warming. In aerobic ecosystem CH₄ is oxidised by methanotrophs to CO₂ a less global warming molecule. However, in anoxic environment CH4 acts as an electron donor and interacts with various electron acceptors. Methane modulates denitrification, Fe reduction, SO₄ reduction and organic matter decomposition. Manuscript elucidates methanogenesis and highlights the pathways of interaction between methanogenesis and cycling of electron acceptors in various anaerobic ecosystems in relation to global C and N balance.

ABSTRACT
Methanogens are primarily anaerobic Archaebacteria representing the most primitive earthly creatures, alive since about 3.5 billion years. While oxygen inhibit their activity, they adapt well in a variety of ecological niche, viz., the intestinal tracts of insects and animals including ruminants, sewage digesters, groundwater and deep soil/water, etc. They are involved in biomethanation that converts organic polymers, including the complex recalcitrant lignocelluloses, to CH₄ and CO₂. Enhancing the process by optimising the physical, chemical and molecular parameters is an interesting biotechnology. Molecular research is rapidly progressing on the genomics, gene and its regulation, and methanogenesis as it expresses. Identifying novel species expressing methanogenesis and manipulating the genetic make-up including through cloning in recent years will set goals and leads for future investigations. The biomethanation enzyme Methyl-CoM-reductase (Mcr) constitutes about 10% of the methanogen protein. Due to its abundance and significance, elucidating its structure and its synthesis and regulation mechanism has received much attention recently. Mcr-coding genes from methanogens have been cloned and sequenced. An approach at the molecular level to enhance biomethanation seems to lie in metagenomics. The microbiology, biochemistry, the roles of the participating microbes, their molecular biology and applications in methanogenesis are discussed in this chapter.

ABSTRACT
Methanogenesis is a ubiquitous process primarily encountered in anaerobic environments. Methanogens are a group of diverse obligate anaerobic bacteria that produce methane from complex organic matter. Despite their differences in morphological characters and habitat, they show coherence in terms of methane-producing metabolic activity. Being distinctive from all other classical prokaryotes, these are grouped under another kingdom of Archea. Other distinctions of the members are based on their unique cell wall structures and membrane components, as well as differences in their highly conserved gene sequences. Methanogens likely owe their cosmopolitan status to their unique mode of energy metabolism of methane generation. They are active in various ecological niches, from rumens of animals to submarine volcanic vents, sewage digestors and landfills. Methanogenic bacteria are abundant in habitats where high affinity electron acceptors are negligible. Methane fermentation involves bacteria that obtain energy by catalysing anaerobically degradable organic matter to CH₄ and CO₂ by consuming H₂, CO₂, and low-carbon organic acids as their substrates. The gaseous products of methanogenesis are greenhouse gases, thus are major contributors to global warming. Methanogens could be used to produce renewable carbon-neutral energy substitute, biogas. Methane cycling archaea play a major role in global methane production as energy for the future.

Applications of Remote Sensing

The era of satellite remote sensing was open in the 1960s when cameras and electronic sensors were mounted on spacecraft. Nowadays there is a big assortment of satellite systems actively recording information about the Earth. A wide variety of imagery is available from satellites. Both active and passive sensors, operating from the microwave to the ultraviolet regions of the electromagnetic spectrum collect a large amount of information about the earth’s surface every day. Each of the systems vary in terms of their spatial, spectral, radiometic and temporal resolution. Those characteristics play an important role in defining which applications the sensor is best suited for. The main benefits of satellite remote sensing are the following:

Introduction

A geographic information system or geographical information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present all types of spatial or geographical data. The acronym GIS is sometimes used for geographic information science (GIScience) to refer to the academic discipline that studies geographic information systems and is a large domain within the broader academic discipline of geoinformatics. What goes beyond a GIS is a spatial data infrastructure, a concept that has no such restrictive boundaries. In a general sense, the term describes any information system that integrates stores, edits, analyzes, shares, and displays geographic information. GIS applications are tools that allow users to create interactive queries (user-created searches), analyze spatial information, edit data in maps, and present the results of all these operations. Geographic information science is the science underlying geographic concepts, applications, and systems.

GIS is a broad term that can refer to a number of different technologies, processes, and methods. It is attached to many operations and has many applications related to engineering, planning, management, transport/logistics, insurance, telecommunications, and business. For that reason, GIS and location intelligence applications can be the foundation for many location-enabled services that rely on analysis and visualization. GIS can relate unrelated information by using location as the key index variable. Locations or extents in the Earth space–time may be recorded as dates/times of occurrence, and x, y, and z coordinates representing, longitude, latitude, and elevation, respectively. All Earth-based spatial–temporal location and extent references should, ideally, be relatable to one another and ultimately to a “real” physical location or extent. This key characteristic of GIS has begun to open new avenues of scientific inquiry.

Introduction

The Global Positioning System (GPS) is a space-based navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. The system provides critical capabilities to military, civil, and commercial users around the world. The United States government created the system, maintains it, and makes it freely accessible to anyone with a GPS receiver. The US began the GPS project in 1973 to overcome the limitations of previous navigation systems, integrating ideas from several predecessors, including a number of classified engineering design studies from the 1960s. The U.S. Department of Defense (DoD) developed the system, which originally used 24 satellites. It became fully operational in 1995. Roger L. Easton, Ivan A. Getting and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it.
 
Advances in technology and new demands on the existing system have now led to efforts to modernize the GPS and implement the next generation of GPS Block IIIA satellites and Next Generation Operational Control System (OCX). Announcements from Vice President Al Gore and the White House in 1998 initiated these changes. In 2000, the U.S. Congress authorized the modernization effort, GPS III. In addition to GPS, other systems are in use or under development. The Russian Global Navigation Satellite System (GLONASS) was developed contem-poraneously with GPS, but suffered from incomplete coverage of the globe until the mid-2000s. There are also the planned European Union Galileo positioning system, China’s BeiDou Navigation Satellite System, the Japanese Quasi-Zenith Satellite System, and India’s Indian Regional Navigation Satellite System.

Digital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing. It allows a much wider range of algorithms to be applied to the input data and can avoid problems such as the buildup of noise and signal distortion during processing. Since images are defined over two dimensions (perhaps more) digital image processing may be modeled in the form of multidimensional systems. Introduction to image processing 
Image processing is a method to convert an image into digital form and perform some operations on it, in order to get an enhanced image or to extract some useful information from it. It is a type of signal dispensation in which input is image, like video frame or photograph and output may be image or characteristics associated with that image. Usually image processing system includes treating images as two dimensional signals while applying already set signal processing methods to them.
Image processing is a method to perform some operations on an image, in order to get an enhanced image or to extract some useful information from it. It is a type of signal processing in which input is an image and output may be image or characteristics/features associated with that image. Now-a-days, image processing is among rapidly growing technologies. It forms core research area within engineering and computer science disciplines too.

Introduction

Although both maps and aerial photos present a “bird’s-eye” view of the earth, aerial photographs are NOT maps. Maps are orthogonal representations of the earth’s surface, meaning that they are directionally and geometrically accurate (at least within the limitations imposed by projecting a 3-dimensional object onto 2 dimensions). Aerial photos, on the other hand, display a high degree of radial distortion. That is, the topography is distorted, and until corrections are made for the distortion, measurements made from a photograph are not accurate. Nevertheless, aerial photographs are a powerful tool for studying the earth’s environment. 

Because most GISs can correct for radial distortion, aerial photographs are an excellent data source for many types of projects, especially those that require spatial data from the same location at periodic intervals over a length of time. Typical applications include land use surveys and habitat analysis. 

This unit discusses benefits of aerial photography, applications, the different types of photography, and the integration of aerial photographs into GISs.

Introduction
Remote sensing is the art and science of recording, measuring, and analyzing information about a phenomenon from a distance. Humans with the aid of their eyes, noses, and ears are constantly seeing, smelling, and hearing things from a distance as they move through an environment. Thus, humans are naturally designed to be remote sensors. In order to study large areas of the Earth’s surface geographers use devices known as remote sensors. These sensors are mounted on platforms such as helicopters, planes, and satellites that make it possible for the sensors to observe the Earth from above.

Definition
Remote sensing can be defined as any process whereby information is gathered about an object, area or phenomenon without being in contact with it. Our eyes are an excellent example of a remote sensing device. We are able to gather information about our surroundings by gauging the amount and nature of the reflectance of visible light energy from some external source (such as the sun or a light bulb) as it reflects off objects in our field of view. Contrast this with a thermometer, which must be in contact with the phenomenon it measures, and thus is not a remote sensing device.

Abstract

Nitrogen is an important nutrient for growth and development of plants. Presence or absence of nitrogen often affects the amino acid composition of proteins, which may in turn change its nutritional quality. Increase in the elevated CO₂ concentration and temperature associated with future climates are expected to affect the nitrogen use efficiency (NUE), growth and grain yield of wheat (Triticum aestivum L.). Atmospheric CO₂ is steadily rising from the current level of approx 384 µLL^-1 and is expected to rises upto 550 µLL^-1 by 2050. It is predicted that the global temperature would increase by 1.5- 4.5^oC. The main future challenge is to feed nine billion people under an altered climate, as this increase in global temperature would affect, negatively or positively the future crop productivity including wheat depending upon the geographical location. The present book chapter summarizes the potential impact of elevated CO₂ and temperature on NUE of Triticum aestivum L.

Heat units also called growing degree-days (GDD), effective heat units, or growing degree units, are a heuristic tool in phenology. GDD is a simple means of relating plant growth, development and maturity to air temperature. The concept is widely accepted as a basis for building phenology and population dynamic models. Degree day units are often used in Agrometeorology, Agronomy, Entomology and Pathology essentially to estimate or predict the lengths of the different phases of development in crop plants, insects, pathogens etc.

The agro-meteorological data after the quality control is used to establish a relationship between the crop and weather or to understand their interactions. In agrometeorological data analysis, statistical tools are used. The frequent use of statistics terms and their computational formulas are given below for ready reference:

Weather has profound influence on agriculture, which demands that the changes in weather conditions are regularly monitored. In qualitative terms, weather conditions are often expressed on the basis of final condition created by interaction of different components. For example, too hot, too cold, sunny or cloudy, humid, dry weather conditions refer to specific atmospheric conditions but are least useful in analyzing the impact of weather on agriculture.
 
The measurements taken at a weather station can include any number of atmospheric observables. The WMO has laid down specifications, procedures and practices in respect of various meteorological matters such as instruments, observations, telecommunications, processing of data, analysis etc.

Weather phenomena are not localized, it moves and varies over space and time. The weather over a place or area is the result of far away weather events/conditions. Acquisition of global scale observation, therefore, becomes a pre-requisite for understanding the physics of the weather and also to represent the weather condition over an area at a particular time. Complex three-dimensional models of weather systems can be made by collecting weather data at multiple levels in the atmosphere. Upper-air data are important to know present weather over a place and crucial for weather forecasting.

Real time weather data at different time intervals is very important for the crop weather studies, but through the agro-meteorological observatories such real time weather data are generally not collected. The acquisition of agro-meteorological data through conventional observatories requires services of trained personnel to collect, compile and creation of weather data base. With the advances in technology, weather observations are automatically recorded, stored and can be transmitted to the remote place with the help of Automatic Weather Station (AWS).

Evapotranspiration (ET) is the combined loss of water from vegetation and soil. When water is not a limiting factor at a site, the rate of ET is primarily controlled by meteorological factors like solar radiation, temperature, wind and relative humidity. The measurement of ET under natural conditions is of great importance in the water resource management and irrigation planning. Potential evapo-transpiration (PET) is the evaporation from a surface if water was never a limiting factor. PE-can also be calculated using empirical formulae.

The information on soil-water content is necessary from the point of view of efficient water management of crop production as water required by crops is to be met from the water stored in their root zone. Soil water content changes periodically as a result of changes in field water balance components namely, precipitation, irrigation, evapotranspiration, runoff and deep percolation. Crop growth is adversely affected if the soil water depletes below certain level. For selection of crops, deciding of irrigation level and frequency of irrigation, the assessment of water content of soil is important.

Water loss from a plant in the form of vapour is known as transpiration. Loss of water vapour mainly from leaf cells through pores but also from the leaf cuticle and through lenticels of the stem. The resistance to diffusion of water vapour through a plant’s stomata is called as stomatal resistance. Whereas, stomatal conductance is a numerical measure of the maximum rate of passage of either water vapour or carbon dioxide through the stomata, or small pores of the plant.

Leaf area is an important attribute in bio-productivity studies, as it bears an important and direct relationship to photosynthesis and transpiration. Leaf area is also important in determining the percentage of solar radiation intercepted by an individual plant or crop canopy. Photosynthesis centers on individual leaf. However, productivity depends not only on individual leaves but on stand of vegetation and canopy structure. The photosynthetic productivity of a canopy depends on both the amount of leaves present and the configuration of the leaves making up the canopy. Thus, leaf area has direct bearing on plant growth and final yield.

The most established method for detecting crop water stress remotely is through the measurement of a crop’s surface temperature. The correlation between surface temperature and water stress is based on the assumption that as a crop transpires, the evaporated water cools the leaves below that of air temperature. As the crop becomes water stressed, transpiration will decrease, and thus the leaf temperature will increase. Other factors need to be accounted for in order to get a good measure of actual stress levels, but leaf temperature is one of the most important.

Photosynthetically active radiation (PAR) is the radiation in the 400-700 nm wave band. For plants, 400-700 nm wave band of the light spectrum is very useful because of photosynthesis activity in this band. A simple integral relationship exists between the number of molecules changed photo-chemically and the photons absorbed within the requisite wave bands regardless of photon energy. Net photosynthesis rates are found to be almost linearly proportional to the radiation intercepted, which can be measured by line quantum sensor.

Pressure of air at a given place is the force exerted against a surface by continuous collision of gas molecules. Pressure may be defined as the force per unit surface area.

Dew acts as a source of moisture for the crop plants. It causes reduction in transpiration rate and saving of soil moisture reserves. Dew fall helps in insect-pest and diseases spread in crop plants.

14.1 Dew and Conditions for Dewfall

The radiational cooling during night causes the moisture to saturate and further cooling results into condensation and depositing this moisture in the form of tiny droplets on the grasses, vegetative and other non-conducting surfaces. This deposition form is known as dew. Clear nights, low wind velocity in the order of 1.0 to 3.0 m/s, presence of moderate to high moisture (RH = 75%) and sufficient radiational cooling are the four necessary and conductive conditions for the occurrence of dew.

The change of state of water form solid or liquid to gaseous form is known as evaporation. It may be defined as the water loss in vapour form from a soil/water surface. The energy used in this process is called as latent heat. The energy of 540 cal/g of water is used in this process. This process plays a major role in the redistribution of thermal energy between the earth and the atmosphere. Water vapour diffuses into the atmosphere from the different natural surfaces like ocean, river, lake, pond, soil and plant etc. It is difficult to measure the evaporation from the natural surfaces. To measure the evaporation from open water surface is easy and is normally in practice. The rate of evaporation is dependent on the size of the measuring surface (Pan) at constant wind speed below saturation point. Therefore a measured surface (Pan) is designed to measure the evaporation.

The solar energy is the main source of energy for the processes occurring at the earth surface and in its atmosphere. Crop production, is in fact an exploitation of solar radiation and plants are the converters of solar energy into a useful form of energy which is biomass and sustain life providing food, fodder, fiber, fuel, fruits etc. Sun energy fulfills two essential needs of the plants i.e.  (i) light for photosynthesis including many other photo processes and functions of the plants, (ii) thermal conditions required for the normal physiological functions of the plant. Thus, the crop production and agriculture is basically dependent on quality and quantity of radiation.

Cloud is a visible aggregate of minute water droplets and/or ice particles, or both in the air usually above the general ground level. Clouds are the most important form of suspended water droplets caused by condensation. There is no precipitation without clouds.

11.1. Measuring Instrument

The cloudy hours are measured with the help of eye or sensory parts of the body. No particular instrument is required for cloud amount or cloud cover measurement in the sky.