eChapters

Introduction
Climate change refers to alterations in the earth's global or regional climates over time, encompassing shifts in atmospheric variability or average conditions over periods ranging from decades to millions of years. The United Nations Framework Convention on Climate Change (UNFCCC) differentiates between "climate change" for human-induced alterations and "climate variability" for other changes. Over the past century, ending in 2005, the average global air temperature near the earth's surface has risen at an estimated rate of 0.74 ± 0.18°C (1.33 ± 0.32°F) (IPCC, 2007). In contemporary discussions, especially within environmental policy, "climate change" often refers to recent climate alterations. Both natural processes and human activities influence the earth's temperature and subsequent climate change. Significant increases in global anthropogenic greenhouse gas (GHG) emissions over the years have been major contributors to global warming. The sun, the earth's primary energy source, has a nearly constant output, but minor variations over extended periods can lead to climate change. Natural processes such as orbital changes (orbital forcing), volcanic eruptions, and greenhouse gas concentrations in the atmosphere also affect the earth's climate. Changes in atmospheric concentrations of greenhouse gases and aerosols, land cover, and solar radiation modify the climate system's energy balance, leading to either warming or cooling.
Volcanic eruptions release several gases, notably sulfur dioxide (SO2), which forms sulfate aerosols (SO4) in the atmosphere. Although linking specific weather events to global warming is challenging, increased global temperatures can result in broader changes like glacial retreat, Arctic shrinkage, and rising sea levels worldwide. Variations in precipitation patterns could lead to floods and droughts. Other impacts may include shifts in agricultural yields, the creation of new trade routes, reduced summer stream flows, species extinctions, and the spread of disease vectors. Most global climate change models predict a decline in snowpack on many western mountain ranges, adversely affecting fish populations, hydropower, water recreation, and water availability for agricultural, industrial, and residential use. Partial loss of polar ice sheets could lead to significant sea level rise, altering coastlines and inundating low-lying areas, with the most significant effects on river deltas and low-lying islands. These changes are projected over millennial timescales, but rapid sea level rise within centuries cannot be ruled out. Current climate change models predict a rise in sea surface temperatures between 2 °C and 5 °C by 2100 (IPCC Third Assessment Report, 2001; Done et al., 2003). According to the climate profile document of Jammu and Kashmir, the region has seen an increase in average temperature, with the Kashmir valley rising by 1.45°C and the Jammu region

Abstract

Aquaculture is facing the serious effects of climate change in the form of scarcity of water and shift in dissolved oxygen level leading to outbreak of diseases. In a study conducted in Farm facilities of ICAR, Tripura it was seen that rise in temperature do have significant effect on hematological and biochemical parameters of fish which are basic index of good health of any organism. Many different diseases occur in the farmers’ pond and which can be controlled. So some basic diseases and their controlling strategies have been pointed out that can lead to better management of fish diseases in pond condition.

Introduction

Seasonal or annual fluctuation in weather patterns is termed as climate variability. However, climate change is a change in the mean state of weather statistic over three decades of time period. Climate change is exacerbating the challenges faced by the agriculture as well as horticulture sector. For last 10 years, Asia is facing the serious threats from climate change and variability such as tsunami, f loods and droughts. Extreme events are expected to have large negative impacts on crop productivity. The rise in temperature and reduction in rainfall under semi-arid environments are likely to reduce production of fruits, vegetables and flowers in the coming 20 years. The production and quality of fresh fruit and vegetable crops can be directly and indirectly affected by exposure to high temperatures and elevated levels of carbon dioxide and ozone. The rise in atmospheric CO2 levels due to global climate change and horticultural practices has both direct and indirect effects on secondary metabolite synthesis in plants.

Introducton

The Working Group Report of Fifth Assessment Report 2013, by UN’s Inter governmental Panel on Climate Change (IPCC) says, that to limit warming to a rise of 2ºC above pre industrial levels, 1000 gigatones (trillion tons) is the upper limit of CO₂ that can be emitted. However, by 2011, we have already emitted 531 gigatones since last 260 yrs and in next 25 years, we will cross 1000 gigatones limit. There is a clear long-term global warming trend. Notably, the 20 warmest years have all occurred since 1981, and the 10 warmest have all occurred in the past 12 years.

ABSTRACT

Among the challenges of 21^st century, to make the food supply sustainable, the impact of climate change is largely unconceivable. The climate on earth has increased by 0.74° C over the past 100 years. Best estimate for low scenario of global warming is 1.8°C and for high scenario is 4°C. Last decade recorded the hottest in the century and 2009 has been rated hottest since 1900. Retreating glaciers have been confirmed in various parts of the world. Further, the current greatest challenge is to perceive the biological impact of such climate changes. Efforts have been initiated by Intergovernmental Panel on Climate Change (IPCC) to assess the impact of climate change on biological systems across the globe. Since 1950’s, the change in carbon dioxide content in the atmosphere is being monitored. Almost a decade later, computer models were employed to assess the possible impact of change in temperature and enhanced CO₂. By the 1980’s consensus was almost achieved on possible doubling of atmospheric CO₂ concentration due to emission from fossil fuels and rise in the global temperature. Since then quantitative estimates on the biological impacts of climate change have been taken up by scientific community world wide. Presently, ample of evidence on impact of climate change from marine to terrestrial environment, from species to communities, ecosystems and hierarchies have been gathered for both flora and fauna (Walther et al., 2002I). Parmesan and Yune (2003) reported that meta-analyses of 334 species and global analyses of 1,570 species revealed highly significant and regular patterns of change in relation to observed warming with more than 95 per cent confidence, as fingerprints of climate change.

Introduction

Climate change refers to change of weather variables over a long period of time. The Inter-Governmental Panel on Climate Change (IPCC) defined climate change as a “change in the state of the climate that can be identified by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer”. This may occur due to natural variability or as a result of human activity. The change may be in the form of magnitude or variability of a single or multiple weather variables or weather phenomena. Global shift in temperature and precipitation pattern as well as increasing frequency of extreme weather events are consequence of climate change which is perceived over several decades. Climate change is indeed increasingly recognized as a considerable risk to agriculture particularly with respect to direct impact on crop production and yield stability (Barzman, 2015).

Effect of Climate Change in Global Warming and Greenhouse Gases

Global warming as the resultant of climate change has become an issue of serious concern worldwide for existence of life on the earth. Over past hundred years, the global temperature has increased by 0.8⁰C and is expected to reach 1.1-5.4⁰C by the end of next century. Major factors affecting the global warming and the climate change is the concentration of greenhouse gases like carbon dioxide, methane and nitrous oxide. On the other hand, CO₂ concentration in the atmosphere has increased drastically from 280 ppm to 370 ppm and is likely to be doubled in 2100 (IPCC, 2007).

10.1 Introduction

The IPCC predicts the global average surface temperature to increase by 1.4 – 5.8 ^oC by 2100 with the increased atmospheric carbon dioxide (CO₂) concentration from 540-970 ppm over the same period. The atmospheric CO₂ concentration and temperature, both, showing a steep rise since last three decades and their impacts experienced across all sectors of agriculture. Serious concerns have been raised about the effects of global environmental change on community and ecosystem functioning. Climate change scenarios generated from General Circulation Models (GCM) with a doubling of atmospheric CO₂ predicted various extreme weather events viz., warming temperatures, increase in anti-cyclonic behaviour during the summer which may result in 20% increase in the precipitation, and long periods of drought between rain bearing storms.

Introduction

According to the Intergovernmental Panel on Climate Change, climate change refers to the long-term changes (typically decades or longer) in the average state of the climate with statistically significant variations.

The climate change, defined as the long-term imbalance of customary weather conditions such as temperature, radiation, wind and rainfall characteristics of a particular region, is likely to be one of the main challenges for mankind during the present century.

A general definition of climate change is a change in the statistical properties (principally the man and spread) of the climate system when considered over long periods.

Climate Resilience

Climate resilience can be generally defined as the capacity for a socioecological system to: Absorb stresses and maintain function in the face of external stresses imposed upon it by climate change. Adapt, reorganize, and evolve into more desirable configurations that improve the sustainability of the system, leaving it better prepared for future climate change impacts.

Prevailing climate and weather conditions play crucial role in production and quality of various fruits including mango (Mangifera indica L.). In India, mango has 2.3 million ha area with annual production of 20.5 million tonnes and average productivity of 8.9 t/ha. However, erratic precipitation and high temperature during flowering and fruit setting induced mainly due to climatic disturbance in the recent past had adversely impacted the production potential of mango in subtropics. Analysis of twenty years (2001-02 to 2021-22) weather data of ICAR CISH, Lucknow, indicated that average annual rainfall of the region is 956.41 mm spread over 25-30 number of rainydays.

INTRODUCTION

Potatois an important crop for food and nutritional security of India. Itis mainly grown as rabi crop and 90 per cent of itscultivation is confined to northern Indo-Gangetic plains comprisingthestatesof UttarPradesh, WestBengal,Bihar, Punjab and Haryana. Due to climate change, the main potato season is likely to be warmer than the rest of the seasonsof the year and will affect seriously the potato production in India. Climate change is defined by Intergovernmental Panel on Climate Change (IPCC) as a plausible future climate thathas been constructedfor explicitusein investigatingthepotential consequences of climate change. It is the difference in climate over a period of time (with respect toa base line or a reference period) and corresponds to a statistically significant trend of meanclimate or itsvariability persistent over along period of time. Climate change may be due to both natural aswell asanthropogenic factors. Reference periods are typically of three decadesused as climatological baseline period in impacts and adaptation assessments to Global climate model. The future climate minus baseline climate are used for model scenario comparison of most climate variables. Typically a number of fixed time horizons in the future are produced from model output.For example 2020 (2010-2039), 2050 (2040-2069), 2080 (2070-2099). Future climates are estimated through models, called global circulation models, or global climate models (GCM). GCM simulations are carried out by means of a large set of heavy computations. The IPCC TAR reported 7 GCMs for developing climate scenarios while IPCC FAR reported 21 different GCMs.

Introduction

Birds lack sweat glands; hence non-evaporative cooling mechanism (radiation, conduction and convection) is the major route of heat dissipation within thermoneutral range. Beyond this TNZ, majority of heat loss occurs as insensible heat loss i.e., Panting. Panting is one of the visible responses in poultry during exposure to heat stress associated with considerable energy expenditure. This specialized form of respiration dissipates heat by evaporative cooling at the surface of the mouth and respiratory passage. Panting increase, the loss of CO2 from the lungs, this leads to a reduction in the partial pressure of CO2 and also reduces bicarbonate levels in blood plasma. In turn, the lowered concentration of hydrogen ions leads to rise in plasma pH, a condition generally referred to alkalosis (Daghir, 2009). Birds also respond by reducing their feed intake and thus metabolizable energy (ME) intake to reduce thermo genesis as an adoptive mechanism. If panting fails to prevent their body temperatures from rising, the birds become listless, comatose and soon die due to respiratory, circulatory or electrolyte imbalances (Saif et al., 2003).

Introduction

In the recent years, climate change emerged as the single most pressing problem globally, and accordingly received an increased attention (Berrang-Ford et al., 2011). It is evident that human activities are responsible for the climate change. Natural processes may also lead to climate variability and change. The climate change forecasts resulted from simulation models indicate that the future climate is likely to turn into more capricious nature with more occurrences of extreme events (IPCC, 2013b). Future projections according to the World Bank (2010) reveal the need of raising food production by 1.8% per annum between 2005 and 2050 due to climate change rather than 1% per annum if there were no impact of climate change. The effect of climate change can be seen on the quantity and quality of various components in the global hydrologic cycle (Milly et al., 2005; Bates et al., 2008).

In South Asia, vulnerabilities to the climate change are the largest in semi-arid and arid countries, where rainfall is concentrated over a few monsoon months, year to year variations are high, and where water resources are decreasing (Lenton, 2004). Cruz et al. (2007) indicated that climate trends and variability can be characterized by increased air temperatures, which are more pronounced during the winters compared to the summers. Across the entire Asia, both spatial and temporal variability in rainfall trends observed during the past few decades may be attributed to climate change. It is likely to happen that climate change will extend the dry season when negligible or very low flows occur, which particularly affects the water management process due to inability to rely on water storage reservoirs or groundwater resources situated at great depths (Giertz et al., 2006).

6.1 Introduction

The change in climatic factors over the years is affecting the entire ecosystem. According to Intergovernmental Panel on Climate Change (2007), the global surface temperature is predicted to increase between 1.4 and 5.8 ^oC by the year 2100. Microbial and plant metabolic processes are often dependent on environmental factors (for e.g. temperature and moisture), enzyme activity, and nutrient availability all of which are likely to be affected by climate change (IPCC, 2007). The global atmospheric concentration of carbon dioxide, an important greenhouse gas (GHG) largely responsible for global warming, has increased from a pre-industrial value of about 280 ppm to 389 ppm at present. Similarly, the global atmospheric concentration of other important GHGs like methane and nitrous oxides has also increased considerably. The increase in GHGs was 70% between 1970 and 2004.

Rising atmospheric CO₂ is able to change the physiological activities of plants and soil micro organisms which in turn control the flow of carbon (C) and nitrogen (N) in terrestrial ecosystems. The change in climatic factors also alters the beneficial plant-microbe interactions, which may be positive, negative, neutral or having variable effects. The survival and activity of microorganisms in the rhizosphere mainly depend on the flow of carbon in the root exudates. The composition of these root exudates is affected by various environmental factors such as soil type, pH, light intensity, oxygen status, soil temperature, soil moisture and nutrient availability. Diverse microbial activities pose a major challenge to predict the response of microbial community to global climate change. These changes in microbial activity have larger impacts on vital ecological processes such as nutrient cycling.

Sericulture, the art and science of silk production through silkworm rearing, is profoundly influenced by weather conditions. Optimal weather is not just beneficial; it’s often a prerequisite for successful mulberry cultivation and healthy silkworm development. Deviations from ideal conditions can lead to decreased productivity, increased disease incidence, and ultimately, economic losses for sericulturists.
20.1. Weather’s Influence on Mulberry Cultivation
Mulberry (Morus spp.) leaves are the sole food source for the most commercially important silkworm, Bombyx mori. Therefore, the health and productivity of mulberry plants are paramount. Weather parameters significantly affecting mulberry growth (Fig. 20.1) include:
Temperature: Mulberry thrives in a mean atmospheric temperature range of 24 to 28oC . While it can survive between 13.0 to 37.7oC, optimal growth and bud sprouting occur within the narrower ideal range. Temperatures outside this can stunt growth and leaf quality.
• Rainfall: An annual rainfall between 600 mm and 2500 mm is suitable for mulberry. In regions with lower rainfall, irrigation becomes essential. Consistent moisture is crucial for leaf yield and quality. Excessive rainfall can lead to waterlogging, harming the plants.

Growing food demand requires increased agricultural productivity, but climate change poses serious challenges to crop protection and food security. Rising temperatures, elevated carbon dioxide, altered precipitation, droughts, floods and extreme weather events directly affect crops and indirectly influence pests, pathogens and their natural enemies. Changes in climatic conditions can alter insect development, survival, reproduction, seasonal activity, geographical distribution and pest status. They may also disrupt host–pest relationships, encourage invasive species and contribute to the decline or displacement of existing species. This chapter examines climate-induced changes in crop-pest scenarios and emphasizes the importance of monitoring, forecasting and adaptive pest-management strategies for protecting agricultural production.

The steadily-increasing human population has led to a rise in the demand for food. As more land comes under agricultural cultivation there will be more pressure on natural ecosystems. Climate change will affect agricultural yield directly because of aberrations in temperature and rainfall, and indirectly through changes in soil quality, pests and diseases. In particular, the yield of cereals is expected to decline in India, Africa, and the Middle East. As the temperature rises conditions will become more favourable for pests such as grasshoppers to complete a number of reproduction cycles and thereby increasing their population. In the higher latitudes (in the northern countries) agriculture will benefit with the rise in temperature as the winter season will be shorter and the growing seasons longer. This will also mean that pests that will move towards the higher latitudes as the temperatures rise. Extreme weather conditions such as high temperature, heavy rainfall, floods, droughts, etc. will also affect crop production.

Abstract

The north eastern region of India, consisting of the eight states of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, has an area of 255 090 km2 with a vigorous monsoon dominated climatic and a dynamic hydro-geomorphic regimes. Endowed with a sub-tropical type of monsoonal climate, the region shows remarkable variability of weather and climate on a regional scale. It possesses about 30% of the total water resources potential and about 41 % of the total hydropower potential of India. The per capita and per hectare availability of water in this region is the highest in the country. The problems of environment degradation in the northeastern areas of India are, primarily impacted by demographic pressure, urbanization, natural disasters, soil erosion and land degradation. The region is visited by the southwest monsoons which make it one of the wettest areas in South Asia as well as highly frequented by the water induced disasters. The rapid melting of glaciers is initially expected to first contribute to excessive water flow and flooding in the region. Eventually with the full loss of glaciers, the shortage, when it comes, will likely arrive much more abruptly in time; with water systems going from plenty to want in perhaps a few decades or less.

5.1 Impact of climate change on agriculture

Climate change has both positive and negatively impact on agriculture, food security and land degradation. Climate change could exacerbate the land degradation processes by increases in rainfall intensity, drought frequency and severity, dry spells, f looding, heat stress, sea-level rise and permafrost thaw. The 1/4^th of ice-free land area in the world is prone to human-induced anthropogenic degradation (Certini and Scalenghe, 2011; Hooke et al., 2012). Soil erosion rate is 20-100 times faster than that of soil formation in agricultural field. The erosion rate is least is zero-tillage (non-disturbed field) and maximum at conventional intensive tillage practices. Climate change further exacerbates the land degradation. The permafrost areas, dry-lands, low-lying coastal regions, river deltas are more vulnerable. The occurrence of drought in dry-land was increased by around 1% per year during 1961-2013 periods. On an average 380-620 million people globally experienced desertification who lived in dry-land areas (1980s and 2000s) in South and East Asia, North Africa, Middle East, Sahara region, and Arabian peninsula. Moreover, people who are already living in degraded/ desertified regions are more negatively affected by climate change.

Specifically, the land surface air temperature has increased about twice as much as the global average temperature since the pre-industrial era. The land-surface air temperature has increased relatively higher than the world’s average surface (land and ocean) temperature since the pre-industrial era (1850-1900). The average land-surface air temperature has enhanced by 1.53°C (1.38-1.68°C), whereas, world’s surface (including land and ocean) air temperature has enhanced by 0.87°C (0.75-0.99°C). Subsequently, global warming triggered the frequency, intensity and duration of heat waves and related damage. The direct and indirect impacts of climate change on global agriculture is summarised below for an overall idea about the importance of the issues.

INTRODUCTION

Aquaculture had undergone rapid expansion and intensification in the recent past and has taken the shape of a full-fledged diversified industry. But the risk involved in aquaculture activity has also increased significantly due to the outbreak of diseases which has a devastating effect on the aquaculture crops. Fish are aquatic and poikilothermic, their existence and performance are dominated by the quality of their environment . The aquatic environment is a complex system subject to constant physical and chemical changes brought about by natural and manmade processes. Therefore, choosing the proper site to develop aquaculture facility is paramount to its success.

A disease is an abnormal condition of an organism caused by infection, inherent weakness or environmental stress; it prevents the organism from functioning normally which ultimately leads to death (Avault, 1998). In an aquatic environment, there is a profound balancing of relationship between host (fish), pathogen and the environment existing and this is the fundamental concept to disease susceptibility of fish (Snieszko, 1973). A disease organism may be present in the environment or host, but will not cause disease as long as the host has high natural resistant or the physical condition of the host is strong. Once the imbalance is created to any of the component, opportunistic pathogen invades the host resulting to the outbreak of disease.