An ecosystem is a community of organisms and their physical environment interacting together. Environment involves both living organisms and the non-living physical conditions.
These two are inseparable but inter-related. The living and physical components are linked together through nutrient cycles and energy flows.

Types of Eco-Systems
An ecosystem can be as small as an oasis in a desert, or as big as an ocean, spanning thousands of miles. There are two types of ecosystem:
• Terrestrial Ecosystem
• Aquatic Ecosystem

Terrestrial Ecosystem
Terrestrial ecosystems are exclusively land-based ecosystems. There are different types of terrestrial ecosystems distributed around various geological zones. They are as follows:
1. Forest Ecosystem
2. Grassland Ecosystem
3. Tundra Ecosystem
4. Desert Ecosystem

• Forest Ecosystem : A forest ecosystem consists of several plants, particularly trees, animals and microorganisms that live in coordination with the abiotic factors of the environment. Forests help in maintaining the temperature of the earth and are the major carbon sink.
• Grassland Ecosystem : In a grassland ecosystem, the vegetation is dominated by grasses and herbs. Temperate grasslands and tropical or savanna grasslands are examples of grassland ecosystems.
• Tundra Ecosystem :Tundra ecosystems are devoid of trees and are found in cold climates or where rainfall is scarce. These are covered with snow for most of the year. Tundra type of ecosystem is found in the Arctic or mountain tops.
• Desert Ecosystem :Deserts are found throughout the world. These are regions with little rainfall and scarce vegetation. The days are hot, and the nights are cold.
• Aquatic Ecosystem : Aquatic ecosystems are ecosystems present in a body of water. These can be further divided  into two types, namely:
  1. Freshwater Ecosystem
  2. Marine Ecosystem
  Freshwater Ecosystem
  The freshwater ecosystem is an aquatic ecosystem that includes lakes, ponds, rivers, streams and wetlands. These have no salt content in contrast with the marine ecosystem.
  Marine Ecosystem
  The marine ecosystem includes seas and oceans. These have a more substantial salt content and greater biodiversity in comparison to the freshwater ecosystem.

Introduction to Geosphere, Biosphere, and Hydrosphere Geosphere

The Geosphere refers to the solid part of the Earth, including its inner layers and surface features.
Components:
Core: The innermost layer, composed of iron and nickel.
Mantle: Semi-solid layer of silicates, responsible for tectonic reactivity.
Crust: The outermost layer, consisting of rocks, minerals, and soil.
Functions:
• Provides the foundation for ecosystems.
• Supplies essential minerals and nutrients.
• Influences landforms and natural processes (e.g., earthquakes, volcanoes).

In this cycle, the melted rock from below the Earth’s crust is blown out to the surface through events as lava. Hardened lava, together with rock materials, is weathered and eroded from earth movements. The eroded particles end up somewhere and build up. After many years of buildup, the pressure from the overlying weight causes them to bury themselves more in-depth in the
crust. They are melted by the extreme heat until they are spewed out to the surface again. You may have noticed that this cycle doesn’t conclude on its own. It is affected by other factors such as the wind, temperature and water, which are a part of other spheres.

Biosphere
The Biosphere includes all living organisms on Earth and their interactions with the physical environment.
Characteristics
• Composed of ecosystems where biotic (living) and abiotic (non-living)
components interact.
• Encompasses regions like forests, grasslands, oceans, and deserts.
Importance
• Supports biodiversity and ecological balance.
• Plays a crucial role in nutrient cycling (carbon, nitrogen).
• Maintains energy flow through food chains and food webs.

The Biosphere comprises all the living components of the Earth. It also includes organic matter that has not yet decayed. The sphere hugely depends on the other three spheres as follows:
• The hydrosphere replenishes plants and animals with water and moisture.
• The geosphere renders a solid surface for the plants and animals to inhabit. It also provides heat from beneath the earth.
• The atmosphere screens the sun’s UV radiation and helps us receive just enough of the sun’s heat.
A theory known as the ecosystem better explains the interaction of the biosphere with the other spheres.

Hydrospheres
The Hydrosphere encompasses all the water on Earth in various forms.
Components:
• Surface Water: Oceans, rivers, lakes.
• Groundwater: Aquifers and water stored beneath the surface.
• Frozen Water: Glaciers, ice caps.
• Atmospheric Water: Water Vapour and clouds.
Functions:
• Regulates Earth’s temperature through heat distribution.
• Provides water for drinking, agriculture, and industry.
• Supports aquatic ecosystems.
The ocean and water bodies absorb the sun’s energy and warm up. Transpiration by trees and evaporation of surface water occurs. The water vapour in the atmosphere condenses to form rain clouds and comes down as rain. The rain falls into water bodies and the cycle continues.
Other spheres are also impacted during the water cycle.
Major issues of Biodiversity
Biodiversity has declined at an alarming rate in recent years, largely as a result of human
activity.
�🌡️ Climate Change
Climate change impacts biodiversity at various levels: species distribution, population
dynamics, community structure and the functioning of the ecosystem.

�Pollution
When we talk about pollution, we may think of car exhaust fumes billowing into the
atmosphere, but biodiversity is not only affected by this type, it is also affected by noise pollution and light pollution.
Destruction of habitats
Soil pollution and changes in its uses due to activities such as deforestation have a negative
impact on ecosystems and the species that make them up.
Invasive alien species
Invasive alien species are the second biggest cause of loss of biodiversity in the world,
according to the United Nations Development Programme (UNDP). They act as predators,
compete for food, hybridise with native species, introduce parasites and diseases, etc.
Overexploitation of the natural environment
The overexploitation of natural resources, that is, their consumption at a speed greater than
that of their natural regeneration, has an obvious impact on the planet’s flora and fauna.
Conservation of Bio-Diversity
Conserving biodiversity requires a combination of strategies at local, national, and global
levels to protect ecosystems, species, and genetic diversity.
1. Protect Natural Habitats
• Establish protected areas such as:
• National Parks
• Wildlife Sanctuaries
• Biosphere Reserves
• Prevent deforestation, habitat destruction, and land-use changes.
2. Sustainable Resource Use
• Promote sustainable farming, forestry, and fishing practices.
• Limit overexploitation of natural resources like timber, fish, and water.
• Encourage the use of alternative resources to reduce pressure on biodiversity.
3. Control Pollution
• Reduce air, water, and soil pollution to protect ecosystems.
• Implement stricter waste management systems.
• Minimise the use of pesticides and chemical fertilisers in
agriculture.
4. Combat Climate Change
• Adopt renewable energy sources to reduce greenhouse gas emissions.
• Support reforestation and afforestation programs to act as carbon sinks.
• Enhance the resilience of ecosystems to adapt to changing climates.
5. Prevent Invasive Species
• Monitor and control the introduction of non-native species.
• Encourage biological control measures to manage invasive species.
6. Promote In-Situ Conservation
• Protect species within their natural habitats.
• Use methods like wildlife corridors to connect fragmented habitats.
• Support local and indigenous communities in managing biodiversity-rich areas.
7. Support Ex-Situ Conservation
• Develop zoos, botanical gardens, and aquariums to preserve species outside
their natural habitats.
• Establish seed banks and gene banks to store genetic material.
• Use captive breeding programs to reintroduce species into the wild.
8. Raise Awareness and Education
• Educate communities about the importance of biodiversity.
• Encourage eco-friendly lifestyles and participation in conservation efforts.
• Promote biodiversity-friendly policies and practices in businesses.
9. Strengthen Laws and Policies
• Implement and enforce biodiversity protection laws, such as the Wildlife
Protection Act or Endangered Species Act.
• Support international agreements like the Convention on Biological Diversity
(CBD) and CITES (Convention on International Trade in Endangered Species).
10. Encourage Community Participation
• Involve local communities in conservation initiatives, such as:
• Joint Forest Management (JFM).
• Sacred groves protection by traditional societies.
• Empower indigenous groups to safeguard biodiversity hotspots.
Concept of sustainability and international efforts for environmental protection
Development which meets the needs of the present without compromising the ability of
future generations to meet their own needs’. This most widely accepted definition of
Sustainable Development was given by the Brundtland Commission in its report Our
Common Future (1987). Sustainable development (SD) calls for concerted efforts towards
building an inclusive, sustainable and resilient future for people and planet
Core Elements of Sustainable Development
▪ Three core elements of sustainable development are economic growth, social
inclusion and environmental protection. It is crucial to harmonise them.
▪ Sustainable economic growth, achieving sustainable livelihood, living in
harmony with nature and appropriate technology are important for sustainable
development.
▪ Environmental Sustainability:
It prevents nature from being used as an inexhaustible source of resources and
ensures its protection and rational use.
Aspects such as environmental conversation, investment in renewable energy,
saving water, supporting sustainable mobility, and innovation in sustainable
construction and architecture, contribute to achieving environmental
sustainability on several fronts.
▪ Social Sustainability:
It can foster gender equality, development of people, communities and
cultures to help achieve a reasonable and fairly-distributed quality of
life, healthcare and education across the Globe.
▪ Economic Sustainability:
Focuses on equal economic growth that generates wealth for all, without harming
the environment.
Investment and equal distribution of economic resources.
Eradicating poverty in all its forms and dimensions.
Emergence of Environmental Issues
Environmental issues have emerged due to human activities like industrialisation, population
growth, urbanisation, and resource exploitation. These activities have led to pollution,
deforestation, habitat destruction, global warming, and biodiversity loss.
Key Causes
1.
2.
3.
4.
5.
Major Issues
Industrialisation: Increased pollution and resource depletion.
Population Growth: Overuse of natural resources.
Urbanisation: Habitat destruction and waste generation.
Agriculture: Soil degradation and water contamination.
Climate Change: Rising temperatures and extreme weather.
• Pollution (air, water, soil).
• Deforestation and biodiversity loss.
• Global warming and resource depletion.
Responses
• Environmental awareness movements (e.g., Chipko Movement).
• Laws and policies (e.g., Wildlife Protection Act).
• Global agreements (e.g., Paris Agreement).
• Adoption of sustainable practices like renewable energy and conservation.
International Protocols
International protocols address global environmental, economic, and social challenges
through collaborative efforts. They aim to regulate activities like trade, greenhouse gas
emissions, and sustainable development.
1. World Trade Organisation (WTO)
• Established in 1995 to promote free trade and resolve trade disputes among
nations.
• Balances trade growth with sustainable development by encouraging eco
friendly practices.
• Concerns: Trade rules may sometimes conflict with environmental protection
measures.
2. Kyoto Protocol (1997)
• A global treaty under the UN Framework Convention on Climate Change
(UNFCCC).
• Aims to reduce greenhouse gas emissions and combat global warming.
Key Features:
• Legally binds industrialized nations to reduce emissions by specific targets.
• Includes mechanisms like Emission Trading, Clean Development Mechanism
(CDM), and Joint Implementation.
Challenges
• The United States did not ratify it.
• Critics argue it lacks strong enforcement mechanisms.
Importance of International Protocols
1.
issues.
goals.
2.
3.
Promote global cooperation in addressing climate change and environmental
Ensure sustainable trade practices through frameworks like the WTO.
Provide mechanisms to monitor and enforce compliance with environmental
International Agreement on Environmental Management
International agreements on environmental management aim to address global environmental
challenges through cooperation, regulation, and shared goals. These agreements focus on
mitigating environmental damage, promoting sustainable practices, and protecting natural
resources.
1. The Paris Agreement (2015)
• Objective: Limit global temperature rise to below 2°C, aiming for 1.5°C,
compared to pre-industrial levels.
Key Features:
• Nationally Determined Contributions (NDCs) for countries to set their climate
action targets.
• Focus on reducing greenhouse gas emissions, with countries reviewing
progress every five years.
• Financial support for developing nations to adapt to climate change and
transition to green technologies.
2. The Kyoto Protocol (1997)
• Objective: Reduce greenhouse gas emissions in industrialised nations by
specific targets.
Key Features:
• Binding commitments for developed countries to cut emissions.
• Mechanisms like Emissions Trading, Clean Development Mechanism (CDM),
and Joint Implementation.
• Criticised for lack of participation from major emitters (e.g., the U.S. and
China).
3. The Convention on Biological Diversity (CBD) (1992)
• Objective: Conserve biological diversity, use biodiversity sustainably, and
share its benefits fairly.
Key Features:
• Nagoya Protocol (2010): Focuses on access to genetic resources and sharing
benefits from their use.
• Targets include protecting ecosystems, conserving species, and integrating
biodiversity into national development plans.
4. The United Nations Framework Convention on Climate Change (UNFCCC) (1992)
• Objective: Stabilise greenhouse gas concentrations in the atmosphere to
prevent dangerous human interference with the climate system.
Key Features:
• Annual conferences (COP) where countries assess progress and commit to
new climate goals.
• Provides a framework for treaties like the Kyoto Protocol and Paris
Agreement.
5. The Stockholm Convention on Persistent Organic Pollutants (2001)
• Objective: Eliminate or restrict the production and use of persistent organic
pollutants (POPs).
Key Features:
• Ban or reduce chemicals that persist in the environment and accumulate in
living organisms.
• Includes chemicals like DDT, PCBs, and dioxins.
6. The Basel Convention (1989)
• Objective: Control the movement of hazardous waste across borders and
minimise its generation.
Key Features:
• Ensures that hazardous waste is managed and disposed of in an
environmentally sound manner.
• Promotes waste minimisation and encourages recycling.
7. The Ramsar Convention (1971)
• Objective: Protect wetlands and ensure their sustainable use.
Key Features:
• Designates wetlands of international importance and promotes their
conservation and restoration.
• Supports sustainable management practices to protect biodiversity and
ecosystem services.