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Dear Aspirants,

This Spotlight is a part of our Mission Nikaalo Prelims-2023.

You can check the broad timetable of Nikaalo Prelims here

Session Details

YouTube LIVE with Parth sir – 7 PM  – Prelims Spotlight Session

Evening 04 PM  – Daily Mini Tests

Join our Official telegram channel for Study material and Daily Sessions Here

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16th May 2023

Climate Change, Pollution

What is Climate Change?

The periodic modification of Earth’s climate brought about due to the changes in the atmosphere as well as the interactions between the atmosphere and various other geological, chemical, biological and geographical factors within the Earth’s system is called Climate change.

Factors Affecting Climate Change

Natural Factors – affect the climate over a period of thousands to millions of years.Such as – 

1. Continental Drift – have formed millions of years ago when the landmass began to drift apart due to plate displacement. This impacts climate change due to the change in the landmass’s physical features and position and the change in water bodies’ position like the change in the follow of ocean currents and winds.
2. Volcanism – Volcanic eruption emits gasses and dust particles that last for a longer period causing a partial block of the Sun rays thus leading to cooling of weathers and influencing weather patterns.
3. Changes in Earth’s Orbit – A slight change in the Earth’s orbit has an impact on the sunlight’s seasonal distribution reaching earth’s surface across the world. There are three types of orbital variations – variations in Earth’s eccentricity, variations in the tilt angle of the Earth’s axis of rotation and precession of Earth’s axis. These together can cause Milankovitch cycles, which have a huge impact on climate and are well-known for their connection to the glacial and interglacial periods.

Anthropogenic Factors – is mainly a human-caused increase in global surface temperature. Such as –

1. Greenhouse Gasses – these absorb heat radiation from the sun resulting in an increase in Global Temperature. GHGs mostly do not absorb solar radiation but absorb most of the infrared emitted by the Earth’s surface. Global warming begins with the greenhouse effect, which is caused by the interaction between incoming radiation from the sun and the atmosphere of Earth.
2. Atmospheric Aerosols – these can scatter and absorb solar and infrared radiation. Solar radiation scatters and cools the planet whereas aerosols on absorbing solar radiation increase the temperature of the air instead of allowing the sunlight to be absorbed by the Earth’s surface. Aerosols have a direct affect on climate change on absorption and reflection of solar radiation. Indirectly it can affect by modifying clouds formation and properties. It can even be transported thousands of kilometres away through winds and circulations in the atmosphere.
3. Shift in land-use pattern – Most of the forests and land covers are replaced by agricultural cropping, land grazing, or for Industrial or commercial usage. The clearing of forest cover increases solar energy absorption and the amount of moisture evaporated into the atmosphere.
   • The lower the albedo (reflectivity of an object in space), the more of the Sun’s radiation gets absorbed by the planet and the temperatures will rise. If the albedo is higher and the Earth is more reflective, more of the radiation is returned to space, leading to the cooling of the planet.

Potential Effects of climate change in India

• Extreme Heat: India is already experiencing a warming climate. Unusual and unprecedented spells of hot weather are expected to occur far more frequently and cover much larger areas. Under 4°C warming, the west coast and southern India are projected to shift to new, high-temperature climatic regimes with significant impacts on agriculture.
• Changing Rainfall Patterns: A decline in monsson rainfall since the 1950s has already been observed. A 2°C rise in the world’s average temperatures will make India’s summer monsoon highly unpredictable. At 4°C warming, an extremely wet monsoon that currently has a chance of occurring only once in 100 years is projected to occur every 10 years by the end of the century. Dry years are expected to be drier and wet years wetter.
• Droughts: Evidence indicates that parts of South Asia have become drier since the 1970s with an increase in the number of droughts. Droughts have major consequences. In 1987 and 2002-2003, droughts affected more than half of India’s crop area and led to a huge fall in crop production. Droughts are expected to be more frequent in some areas, especially in north-western India, Jharkhand, Orissa, and Chhattisgarh. Crop yields are expected to fall significantly because of extreme heat by the 2040s.
• Groundwater: Even without climate change, 15% of India’s groundwater resources are overexploited. Falling water tables can be expected to reduce further on account of increasing demand for water from a growing population, more affluent lifestyles, as well as from the services sector and industry.
• Glacier Melt: Most Himalayan glaciers have been retreating over the past century. At 2.5°C warming, melting glaciers and the loss of snow cover over the Himalayas are expected to threaten the stability and reliability of northern India’s primarily glacier-fed rivers. Alterations in the flows of the Indus, Ganges, and Brahmaputra rivers could significantly impact irrigation, affecting the amount of food that can be produced in their basins as well as the livelihoods of millions of people
• Sea level rise: With India close to the equator, the sub-continent would see much higher rises in sea levels than higher latitudes. Sea-level rise and storm surges would lead to saltwater intrusion in the coastal areas, impacting agriculture, degrading groundwater quality, contaminating drinking water, and possibly causing a rise in diarrhoea cases and cholera outbreaks, as the cholera bacterium survives longer in saline water. Kolkata and Mumbai, both densely populated cities, are particularly vulnerable to the impacts of sea-level rise, tropical cyclones, and riverine flooding.
• Apart from this food and energy security are also major concerns. Water scarcity, health hazards among the masses, and migration and political conflicts are expected to grow.

India’s response to Climate Change

• National Action Plan on Climate Change (NAPCC): outlines existing and future policies and programs addressing climate mitigation and adaptation. The Action Plan identifies eight core “national missions” running through to 2017: Solar Energy; Enhanced Energy Efficiency; Sustainable Habitat; Water; Sustaining the Himalayan Ecosystem; Green India; Sustainable Agriculture; and Strategic Knowledge for Climate Change. Most of these missions have strong adaptation imperatives.
• National Clean Energy Fund: The Government of India created the National Clean Energy Fund (NCEF) in 2010 for financing and promoting clean energy initiatives and funding research in the area of clean energy in the country. The corpus of the fund is built by levying a cess of INR 50 (subsequently increased to INR 100 in 2014) per tonne of coal produced domestically or imported.
• Paris Agreement: Under the Paris Agreement, India has made three commitments. India’s greenhouse gas emission intensity of its GDP will be reduced by 33-35% below 2005 levels by 2030. Alongside, 40% of India’s power capacity would be based on non-fossil fuel sources. At the same time, India will create an additional ‘carbon sink’ of 2.5 to 3 billion tonnes of Co2 equivalent through additional forest and tree cover by 2030.
• International Solar Alliance: ISA was launched in Paris on 30 November 2015 by India and France, in the presence of Mr. Ban Ki Moon, former Secretary-General of the United Nations.
• Bharat Stage (BS) Emission Norms: Emissions from vehicles are one of the top contributors to air pollution, which led the government at the time to introduce the BS 2000 (Bharat Stage 1) vehicle emission norms from April 2000, followed by BS-II in 2005. BS-III was implemented nationwide in 2010. However, in 2016, the government decided to meet the global best practices and leapfrog to BS-VI norms by skipping BS V altogether.

All these efforts need to be implemented well to mitigate the effects of climate change.

How can India cope with climate change effects?

An ‘adaptation’ approach is the way to go. For this, a big push must be given to the interlinking of rivers and the use of GM crops. Climate action has globally been ‘mitigation-centric’ — most of the programs (such as a push for renewable energy and electric vehicles) are aimed at slowing down future global warming. ‘Mitigation’ is more important to developed countries, but for countries like India, the focus should be on ‘adaptation’, or measures are taken to cope with the inevitable effects of climate change that has already happened, such as nasty storms, floods, and droughts.

‘Adaptation’ is like protecting yourself against a punch that will land. India has also been mitigation-centric; it is time to bring focus on ‘adaptation’. And for adaptation, the time has come for two major steps.

• The first is to give a big push to a 150-year-old idea — inter-linking of rivers (ILRs). With floods and droughts likely to occur in different parts of the countries, possibly alongside each other, there is no option but to make ILR happen, and fast. Here are two components of it: the Himalayan and the Peninsular, with 14 and 16 links respectively. The idea is to build a dam on one river so that the water level rises at the head of the canal, allowing water to flow by gravity to the next river. India today has 5,100 large dams, which have walls at least 15 meters tall; ILR will require 3,000 more. The project will also involve building 15,000 km of new canals. If brought to fruition, ILR will bring 35 million hectares — over twice the size of Andhra Pradesh — of additional land into cultivation, and 34,000 MW more of hydroelectricity.
• The other adaptive measure is genetically modified crops. GM technology is a major component of ‘climate-smart agriculture’. We would need drought-resistant crops, and crops that produce more on the same patch of land so that climate-impairing ‘land use’ is minimized. India has been saying ‘no’ to GM technology. However, GM technology has been in use globally for over two decades and millions of people have been eating GM foods for years.

Dear Aspirants,

This Spotlight is a part of our Mission Nikaalo Prelims-2023.

You can check the broad timetable of Nikaalo Prelims here

Session Details

YouTube LIVE with Parth sir – 7 PM  – Prelims Spotlight Session

Evening 04 PM  – Daily Mini Tests

Join our Official telegram channel for Study material and Daily Sessions Here

---

15th May 2023

Basic Concepts of Ecology, Biodiversity

Ecology

• Ecology is the study of the relationships between living organisms, including humans, and their physical environment; it seeks to understand the vital connections between plants and animals and the world around them
  • Also, Ecology also provides information about the benefits of ecosystems and how we can use Earth’s resources in ways that leave the environment healthy for future generations.
• The term “ecology” was coined by the German zoologist, Ernst Haeckel, in 1866
• Also, ancient Indian texts have references to Ecological principles as follows:
  • The classical texts of the Vedic Period such as the Vedas, the Samhitas, the Brahmanas and the Aranyakas-Upanishads contain references to ecological concepts
• Further, a conceptual understanding of ecology is found in the broader details of study, including:
  • life processes explaining adaptations
  • distribution and abundance of organisms
  • the movement of materials and energy through living communities
  • the successional development of ecosystems, and
  • the abundance and distribution of biodiversity in context of the environment

Components

• Ecology mainly involves the study of biotic and abiotic factors with the environment
• Biotic components include the living factors of an ecosystem.
  • Examples include bacteria, animals, birds, fungi, plants, etc.
• Abiotic components include the non-living chemical and physical factors of an ecosystem
  • Examples include sunlight, soil, air, moisture minerals etc.

Types of Ecology

• • Microbial Ecology
    • Microbial ecology looks at the smallest fundamental levels of life, that is, the cellular level
    • Here, the connections are made between microbes and their relationships with each other and their environments
    • This is particularly important in the analysis of evolutionary connections and events leading to existence
  • Organism/Behavioural Ecology
    • This is the study of the organism at its fundamental levels and can encompass microbial ecology.
    • In this type of ecology, the main goal is to understand the organism’s behaviours, adaptations for such behaviours, reason for those behaviours as explained through the lens of evolution, and the way all these aspects mesh together
  • Population Ecology
    • Population ecology focuses on the population, defined as a group of organisms of the same species living in the same area at the same time
    • Here, attention is given to things such as population size, its density, the structure of the population, migration patterns, and the interaction between organisms of the same population.
  • Community Ecology
    • Community ecology takes a look at the community, defined as all the populations that live in a given area. This includes all the different species populations.
    • The focus here is usually on the interactions between the different species and how their numbers and sizes all mesh together and how change in one population change the dynamic of the whole community
  • Ecosystem Ecology
    • Ecosystem ecology makes a unique contribution to understanding ecology by adding abiotic (non-living) factors to the items analysed, alongside the biotic (living) factors involved.
    • This interaction therefore involves all aspects of the environment and how they interact
  • Global Ecology (Biosphere)
    • The global ecology is principally important in understanding all the ecosystems affecting the entire globe.
    • This includes all the different biomes, with considerations of aspects such as climate and other environmental geography

Examples of Ecology study

• In recent years, the red panda population has dropped significantly, leading conservation groups to classify it as a vulnerable or endangered species
• Ecologists have found that biotic factors, such as logging of trees and introduction of diseases from domestic dogs, played a major role in the decline of red panda populations
• Abiotic factors have been less important to date, but changing temperatures could cause further habitat loss in the future
• So, understanding the main ecological factors responsible for the decline in red panda numbers helps ecologists form conservation plans to protect the species

Levels of Organisation

• Individual, Species, Organism
  • Organism in this level has the ability to act or function independently
  • Here, Individuals do not breed with individuals from other groups
• Population
  • A group of individuals of a given species that live in a specific geographic area at a given time
  • Populations include individuals of the same species, but may have different genetic makeup such as hair/eye/skin colour and size between themselves and other populations
• Community
  • It includes all the populations in a specific area at a given time. A community includes populations of organisms of different species
  • These are generally named after the dominant plant species
• Ecosystem
  • Ecosystems include more than a community of living organisms (biotic) interacting with the environment (abiotic)
  • Everything that lives in an ecosystem is dependent on the other species and elements that are also a part of the ecological community
• Biome
  • A Biome is a set of ecosystems sharing similar characteristics with their abiotic factors adapted to their environments
• Biosphere
  • When we consider all the different biomes, each blending into the other, with all humans living in many different geographic areas, we form a huge community of humans, animals and plants, and micro-organisms in their defined habitats. A biosphere is the sum of all the ecosystems established on planet Earth

Principles of Ecology

• Evolution organizes ecological systems into hierarchies
  • Individual organisms combine into populations, populations combine into species, species combine into higher taxa like genera and phyla.
  • Each can be characterized by its abundance and diversity (number of kinds) in a given ecosystem or study plot
• The sun is the ultimate source of energy for most ecosystems
  • Life runs on the carbon-rich sugars produced by photosynthesis; every ecosystem’s sugar output depends on how much solar energy and precipitation it receives
• Organisms are chemical machines that run on energy
  • The laws of chemistry and physics limit the ways each organism makes a living and provide a basic framework for ecology.
  • The supply of chemical elements and the sugars needed to fuel their assembly into organisms limit the abundance and diversity of life
• Chemical nutrients cycle repeatedly while energy flows through an ecosystem
  • The atoms of elements like Carbon, Nitrogen and Sodium go back and forth from spending time in living to spending time in dead parts of an ecosystem.
  • But the photons of solar energy can be used only once before they are lost to the universe
• Organisms interact—do things to each other—in ways that influence their abundance
  • Individual organisms can eat one another, compete for shared resources, and help each other survive.
  • Each pair of species in an ecosystem can be characterized by the kind and strength of these interactions
• Ecosystems are organized into webs of interactions
  • The abundance of a population is influenced by the chains of interactions that connect it to the other species in its ecosystem
  • This often leads to complex behaviour, and a key challenge in ecology is to determine what patterns of abundance and diversity can be predicted
• Human populations have an outsized role in competing with, preying upon, and helping other organisms
  • Humans are one of millions of species embedded in Earth’s ecosystems. The ability of humans to change the planet, abetted by our large population size and technological prowess, increases our ability to shape the biosphere’s future
• Ecosystems provide essential services to human populations
  • These include products like timber, fibre and food, regulating water and air quality, and cultural benefits like recreation. A key goal of ecology is to use the above principles to preserve ecosystem services.

Biodiversity

Biodiversity can be defined as a community of all the living organisms on the earth and the diversity among them from all the ecosystems. Biodiversity is thus the variability between the species, within the species, and between the ecosystem.

The term biodiversity was coined by Walter G. Rosen in the year 1986.

Types of Biodiversity

Biodiversity can be categorized into three main types:

1. Genetic Diversity (Diversity within species)
2. Species Diversity (Diversity between species)
3. Ecosystem Diversity (Diversity between ecosystem)

Genetic Diversity

Every individual of a particular species differs from each other in its genetic makeup. This genetic variability among the members of any plant or animal species is known as genetic diversity. When two individuals are closely related, they share more genetic information and hence, are more similar.

Species Diversity

Species diversity can be defined as the variety of species within a particular region or habitat. This type of diversity can be found in both the natural ecosystem and agricultural ecosystem.

There are more than 85,000 flowering plant species in tropical North and South America, tropical and subtropical Asia has more than 50,000 flowering plants whereas, there are only 35,000 flowering plant species in tropical and subtropical Africa. But, Europe has around 11,300 vascular plants. Also, other areas, such as salt flats or a polluted stream, have fewer species.

Ecosystem Diversity

There is a large diversity of different ecosystems that have distinctive species. This ecosystem varies with each other as per their habitats and the difference in their species. This ecosystem diversity can be found within a specific geographical region or a country or a state. This type of diversity also includes forests, grasslands, deserts, and mountains.