Global & Regional Ecological Changes & Imbalances | Geography Optional for UPSC (Notes) PDF Download

Introduction

• We currently live in a world experiencing significant impacts on the environment due to human activities. These impacts include climate change, declining populations of numerous species, pollution affecting both ecosystems and human health, and new challenges for human societies, such as sea-level fluctuations, diseases, food security, and extreme weather conditions.
• Researchers investigating global environmental changes aim to understand the effects of various factors, such as human population growth, consumption, energy use, changes in land use, and pollution, on biological systems at multiple scales, ranging from individual organisms to populations, communities, and entire ecosystems (Vitousek 1994).
• The study of global environmental change is a highly interdisciplinary field, involving collaboration among physical scientists who specialize in areas like climate, oceans, atmosphere, and geology, as well as biologists who focus on physiology, evolution, and ecology. This collective effort helps to better understand the complex interactions between human activities and the environment, and to develop strategies to mitigate these impacts.

Drivers of Global Change

Human Population and Consumption

• The Earth is currently home to almost 7 billion people, with the human population experiencing rapid growth, particularly over the past 300 years. This growth trend is unprecedented in population change history. Demographers predict that by 2050, the world population will reach 9 billion, eventually stabilizing between 9 and 12 billion people by the end of the century.
• In most modern societies, a larger population necessitates more resources like food, energy, and minerals, as well as larger economies to support economic development and improved living standards. As a result, population growth and the increased demand for natural resources are significant factors contributing to global environmental change.
• However, the relationship between population size and resource consumption is not straightforward. Factors like affluence (wealth per person) and societal consumption norms also play crucial roles. For instance, China and India have populations of approximately 1.32 and 1.14 billion people, respectively, which is four times the population of the United States. Despite this, the energy consumption per person in the US is six times higher than in China and 15 times higher than in India. This means that even countries with smaller populations can have a more significant environmental impact due to higher resource demand in wealthy, developed nations like the US.
• For much of the past century, the US was the largest greenhouse gas emitter, primarily due to high levels of affluence and energy consumption. However, in 2007, China surpassed the US in overall CO2 emissions because of its economic development, increasing personal wealth, and growing demand for consumer goods, including automobiles.

Energy Use/Climate Change

• Fossil fuels, which include oil, coal, and natural gas, make up 85% of the world's energy consumption. The widespread reliance on fossil fuels is a relatively new phenomenon that began in the 19th century with the discovery of oil and the industrialization of economies. It then expanded rapidly in the 20th century due to economic development, rising populations, and increasing affluence. From 1860 to 1991, energy use per person increased by more than 93 times, while the world population only increased four-fold, demonstrating that growing wealth and consumption drive energy demand.
• The burning of fossil fuels releases around 8.5 billion tons of carbon (in the form of CO₂) into the atmosphere each year, causing a rise in the concentration of CO₂ and strengthening Earth's greenhouse warming effect. This leads to an increase in global air temperatures, which have risen by approximately 0.9°C since 1880. The top five CO₂-emitting countries and regions—China, the US, the EU, Russia, and India—account for two-thirds of global emissions.
• To determine the impact of added greenhouse gases on air temperature and precipitation, global change scientists use climate models. These models suggest that if the burning of fossil fuels continues at its current rate, global temperatures could increase by as much as 4°C by the year 2100. Precipitation changes are also expected, with increased rainfall in mid-to-high latitude regions and increased droughts projected for subtropical regions.

Land Use Changes

• Land use transformations are occurring all around the world as natural land cover types like forests, grasslands, and deserts are being altered into human-dominated ecosystems, such as cities, agricultural areas, and managed forests. Each year between 2000 and 2010, around 13 million hectares of land, equivalent to the size of Greece, underwent changes in land cover (FAO 2010).
• In the past few centuries, developed regions such as the US and Europe experienced substantial loss of forest and grassland cover during periods of economic growth and expansion. Similarly, over the past 60 years, developing countries have also witnessed significant forest losses, particularly in biodiversity-rich areas like Southeast Asia, South America, and West Africa.
• These land use changes impact the biosphere in several ways. For instance, they often lead to the reduction of native habitat, making it increasingly challenging for species to survive. Additionally, some land use changes, like deforestation and agriculture, result in the removal of native vegetation, which in turn reduces carbon uptake through photosynthesis and accelerates soil decomposition. This process contributes to the release of more greenhouse gases. It is estimated that nearly 20% of global CO₂ emissions (1.5-2 billion tons of carbon) come from deforestation.

Pollution

• Pollution, a harmful by-product of economic development, has resulted from increased use of petroleum throughout the twentieth century as synthetic products like plastics, pesticides, solvents, and other chemicals have become essential in our lives. Pollution comes in various forms, such as air and water pollution, and has significant impacts on both human and ecological health. One of the most critical issues related to pollution is the depletion of the ozone layer.
• The ozone layer, located in the Earth's stratosphere, serves as an effective filter for harmful solar ultraviolet (UV) rays. In recent years, scientists have observed a seasonal thinning of this layer, especially over the South Pole, leading to the phenomenon known as the ozone hole. This depletion allows more harmful UV-B radiation to penetrate the Earth's atmosphere, potentially causing damage to human health, forests, and grasslands. There are both natural and human-related causes for ozone layer depletion.
• Natural causes of ozone depletion include substances such as hydrogen oxide (HOx), methane (CH₄), hydrogen gas (H₂), nitrogen oxides (NOx), and chlorine monoxide (ClO). During volcanic eruptions, a significant amount of chlorine may be released into the stratosphere, and tiny particles known as stratospheric aerosols can also contribute to ozone destruction. On the other hand, human activities have led to the release of chlorine atoms into the atmosphere, causing severe ozone depletion. The most damaging agents are human-made chlorofluorocarbons (CFCs), which are commonly used as refrigerants and in aerosol spray cans. In the stratosphere, chlorine atoms from CFCs react with ozone, forming chlorine monoxide and oxygen molecules, ultimately leading to ozone layer depletion.

In conclusion, pollution is a significant global issue that affects human and ecological health. The depletion of the ozone layer is a crucial aspect of this problem, with both natural and human-related causes contributing to its deterioration. Addressing pollution and its impacts on the environment is essential for the well-being of our planet and future generations.

Effect of O3-Layer Depletion

Measures to Prevent Ozone (O₃) Layer Depletion
The global community has made significant progress in preventing ozone layer depletion through international agreements such as the Helsinki (1989) and Montreal (1990s) conventions and protocols. A total ban on the use of CFCs and other ozone-depleting chemicals is highly recommended. Additionally, the temporary use of HCFCs (Hydrochlorofluorocarbons) as a substitute for CFCs is suggested, as they cause less damage to the ozone layer, but it is important to note that they are not entirely ozone-safe.

• Global Warming: Over time, it has become evident that the earth is gradually getting warmer. The primary greenhouse gas (GHG) responsible for global warming is carbon dioxide. Although present in tiny amounts, chlorofluorocarbons (CFCs) also significantly contribute to global warming.
• Effects on Living Beings: Increased CO₂ levels in the atmosphere may boost photosynthetic productivity in plants, resulting in more organic matter production. While this might seem positive, it has several negative consequences:
  • Rapid proliferation of weeds, often at the expense of beneficial plants.
  • Increased numbers of insects and other plant-eating pests.
  • Adverse effects on the survival of other organisms.

Strategies to Combat the Greenhouse Effect
Immediate steps must be taken to minimize global warming by reducing greenhouse gas emissions, especially carbon dioxide. The following measures can help reduce emissions and the release of greenhouse gases into the atmosphere:

• Improve fuel efficiency in power plants and vehicles.
• Develop and implement solar energy and non-fossil fuel alternatives.
• Halt deforestation.
• Support and undertake tree planting (afforestation).
• Reduce air pollution.

Loss of Biodiversity:

• Biodiversity refers to the variety of life on earth and its biological diversity. It enhances ecosystem productivity, with each species, no matter how small, playing a crucial role in enabling the ecosystem to prevent and recover from various disasters. However, human activities are now altering biodiversity and causing massive extinctions. Rapid global warming can also affect ecosystems' ability to adapt naturally.
• Ecological imbalance is often caused by increasing industrialization, irrational consumption of natural resources, deforestation, and water pollution. By harming nature, humans are jeopardizing their own existence. This also results in numerous problems for humanity, such as demographic crises, hunger, scarcity of natural resources, and environmental destruction. Unjustified deforestation leads to the disappearance of animals and birds, which in turn disrupts the ecological balance.

Impact of Environmental Pollution and Imbalanced Ecosystems
Some significant impacts of polluted environments and imbalanced ecosystems are as follows:

Effects on Human Health

• Polluted air, water, and land create a breeding ground for harmful chemical and biological agents that negatively impact human health. These environmental pollutants can facilitate the spread of various communicable diseases through human and animal waste products. A prime example of this is the plagues during the middle ages, where diseases were transmitted through rats that fed on contaminated human waste.
• In developed countries, the prevalence of major diseases spread through the environment has been significantly reduced due to immunization and sanitation programs. However, no country is completely safe from the outbreak of such diseases. This was evident in 2003 when Severe Acute Respiratory Syndrome (SARS) affected numerous countries, demonstrating that diseases transmitted through the environment remain a global concern.

Soil Degradation

• Soil degradation is a critical issue that must be addressed to maintain soil productivity. There are numerous factors contributing to soil degradation, including improper land use, soil erosion, acidification, salinization, waterlogging, and chemical degradation.
• Soil erosion refers to the removal of topsoil due to water or wind. While this process can occur naturally, human activities that lead to the loss of natural vegetation significantly exacerbate the problem. The protection offered by natural vegetation is crucial in preventing soil erosion.
• Acidification and salinization are processes that directly impact soil fertility. Acidification can result from acid rain, while salinization occurs due to the buildup of water-soluble salts in the soil. Both of these processes can lead to decreased soil fertility, affecting the productivity of the land.
• Chemical degradation of soil can happen when essential nutrients are leached from the soil or when harmful chemicals like DDT and radioactive substances are introduced. This type of degradation can also negatively impact soil fertility and overall land productivity.

In summary, soil degradation is a pressing global issue that must be addressed to ensure the long-term productivity of our lands. The primary concerns include soil erosion, acidification, salinization, and chemical degradation, all of which can significantly impact soil fertility and land productivity.

Desertification

• Desertification refers to the process of land degradation in arid, semi-arid, and dry sub-humid areas due to various factors, including severe droughts and human activities. Deserts can be classified into several types, including rainless deserts, run-off deserts, rainfall deserts, and man-made deserts, based on their climatic conditions and human influence.
• Rainless deserts are regions where annual rainfall is virtually nonexistent, while run-off deserts experience low and erratic annual rainfall of less than 100 mm. Rainfall deserts receive insufficient rainfall for crop production, typically between 100-200 mm. Man-made deserts are areas with a semi-arid climate, receiving 200-350 mm of rainfall annually, which have been transformed into deserts due to human overexploitation of the land.
• Desertification occurs as a result of a combination of severe, recurring droughts and human activities that overexploit dryland resources. The solutions to this problem involve reversing the process through natural or artificial means of restoring the environment's biological health. Several countries, such as the United States, Australia, and Israel, have gained valuable experience in combating desertification. Although the implementation of corrective measures can be costly, the overall benefits of these efforts outweigh the expenses.

Genetic Resource Depletion

Genetic resources, which include the genetic material found in domesticated crops, trees, livestock, aquatic animals, and microorganisms, play a crucial role in breeding programs. These programs aim to improve various aspects of these organisms, such as yield, nutritional quality, taste, durability, resistance to pests and diseases, and adaptability to different soil types. However, due to the intense focus on achieving high performance and uniformity in modern food production, the genetic foundation of many crops and animals has become alarmingly limited. This narrow genetic base can pose risks to the sustainability and resilience of our food systems.

Contamination of Food

• Food and livestock feed can be contaminated by chemicals from various sources. For instance, pesticides used in agriculture may end up in crops, while veterinary drugs and growth-promoting chemicals for animals can find their way into meat and dairy products such as milk and butter. Some food preservatives, like sodium nitrite, as well as chemicals and materials in food packaging, can also contaminate the packaged food. Moreover, crops may be exposed to chemical contamination from industrial emissions in the air or effluents from industries. The increasing centralization of food processing, handling, and distribution, along with the growing reliance on large storage facilities, may exacerbate these issues.
• Global stakeholders are responsible for raising awareness and taking action to protect the environment and combat environmental degradation. As environmental degradation affects society and has implications for the socio-economic progress of a nation, law courts must proactively enforce environmental protection laws and regulations. However, ineffective enforcement by government agencies and non-compliance by polluters have led to accelerated environmental degradation. Environmental issues are not limited to individual countries but are now a concern for the international community.
• It is essential to maintain an ecological balance, where living and non-living elements interact with each other to sustain the environment. Unfortunately, human activities have polluted the environment in the quest for civilization. As a result, there is a growing need for sustainable development, which emphasizes the importance of considering future generations and ensuring the planet remains habitable for them.

In India, ecological imbalance can be attributed to five main factors:

• Degradation of Land and Soil Erosion: The deterioration of land quality and increased soil erosion due to various human activities have led to ecological imbalance.
• Deforestation: The large-scale cutting down of trees for various purposes, such as urbanization and agriculture, has disrupted ecosystems and caused ecological imbalance.
• Faulty Utilization of Water Resources: Mismanagement and overuse of water resources have resulted in water scarcity and pollution, contributing to ecological imbalance.
• Environmental Problems from Faulty Mining Practices: Irresponsible mining practices have led to land degradation, water pollution, and the destruction of natural habitats, causing ecological imbalance.
• Industrial and Atmospheric Pollution: Pollution from industries and human activities has severely impacted air quality, leading to various environmental and health issues and contributing to ecological imbalance.

Degradation of Land and Soil Erosion:
The Ministry of Agriculture, Government of India has reported about the serious problem of land degradation and soil erosion as given in Table.

The table reveals that about 174 million hectares (i.e., 53 percent of the total land area) of land in India is facing the serious problem of land degradation out of which 144 million hectares is subjected to soil erosion through water and wind and the rest 30 million hectares is subjected to other problems. Moreover, heavy population pressure has led to the conversion of forest and permanent pastures into croplands leading to indiscriminate grazing.

Deforestation

• Deforestation has been a significant issue in India since its independence, primarily due to the over-exploitation and mismanagement of forest resources. Between 1951 and 1972, the country lost approximately 3.4 million hectares of forestland, with about 70% of that area being used for river valley projects, road and communication infrastructure, and industrial development. The rapid pace of deforestation has continued, resulting in a severe imbalance in India's ecology.
• According to the National Committee on Environmental Planning, only 12% of India's total land surface has adequate tree cover, despite official statistics claiming that it covers 22% of the country's total geographical area. The Himalayan ranges, stretching from Kashmir to North-East India, have experienced particularly high levels of deforestation, leading to an ecological crisis in the country.

Faulty Utilisation of Water Resources:

• India, despite being one of the wettest countries globally, continues to face issues such as floods and droughts due to improper management of water resources. Since gaining independence, India has primarily focused on the construction of large dams, which has had several negative consequences.
• These massive dams have led to the displacement of millions of tribal people and the submersion of vast areas of valuable forest land. Additionally, they have been unable to effectively prevent or control floods and have even caused destructive flash floods in downstream valleys. Recent estimates show that the area affected by floods in India has doubled from 20 million hectares in 1971 to 40 million hectares today.
• Furthermore, these large dams and multi-purpose projects have resulted in negative environmental impacts, including soil degradation in the command areas due to persistent waterlogging and increased soil salinity. A significant portion of the salinity-affected areas can be found in the Indo-Gangetic plains of Uttar Pradesh, Punjab, and Haryana.

Environmental Problems from Faulty Mining Practices:

• In India large-scale extraction of minerals are creating serious environmental problems, ruining the country‘s land, water, forest, and air. Large-scale mining has resulted in the conversion of agricultural and forest land into stockyards townships, roads, railway lines, etc., and removed vegetation and topsoil.
• The disposal of mining waste, mineral dust from mines are constantly polluting the air and also reducing agricultural productivity. Underground mines are often creating subsidence of land due to it‘s overexploitation. Mining activity is also polluting water resources as the rain waters, passing through mineral wastes, are flowing into rivers and streams.
• The mining operation has also resulted in large-scale deforestation, soil erosion and is also responsible for various health hazards to human beings in the form of respiratory problems and other illnesses. Thus in the new Mineral Policy, 1993, attempts have been made to check this environmental pollution arising out of mining operations and to follow some reclamation measures.

Industrial and Atmospheric Pollution

• In India, the rapid, unplanned, and unregulated growth of industries, combined with poorly maintained vehicles, contributes significantly to atmospheric pollution and presents a range of environmental challenges. Key air pollutants include carbon dioxide, carbon monoxide, nitrogen oxides, sulfur dioxide, hydrocarbons, and traces of metals.
• Additionally, specific pollutants are released into the atmosphere, such as lead from vehicle emissions, urea dust from fertilizer plants, cement and lime dust from cement factories, and increasing radiation from nuclear power stations. Furthermore, industrial waste produced by fertilizer plants, paper mills, and leather factories is frequently discharged into rivers, lakes, and oceans, posing significant health risks for the country's population.
• Given the current situation, environmental problems in India are escalating in severity. It is crucial for the nation's planners and policymakers to take necessary steps to reduce the extent of environmental pollution and prioritize the preservation of a healthy environment.

Conclusion

In conclusion, India faces several critical environmental challenges, including land degradation, deforestation, improper water resource management, pollution from mining practices, and industrial and atmospheric pollution. These issues have led to ecological imbalances, health hazards, and reduced agricultural productivity. It is crucial for India's planners and policymakers to take necessary steps to address these environmental problems and prioritize the preservation of a healthy environment for the well-being of the nation and future generations.

Frequently Asked Questions (FAQs) of Global & Regional Ecological Changes & Imbalances

What are the main drivers of global environmental change?

The main drivers of global environmental change include human population growth and consumption, energy use, land use changes, and pollution. These factors contribute to issues such as climate change, loss of biodiversity, soil degradation, and depletion of natural resources.

How does population growth and consumption contribute to environmental change?

Population growth and increased demand for resources, such as food, energy, and minerals, are significant factors contributing to global environmental change. Larger populations require more resources and larger economies to support economic development and improved living standards. Additionally, wealthier nations tend to have higher resource consumption, leading to a greater environmental impact.

What are the consequences of deforestation and land use changes?

Deforestation and land use changes impact the biosphere in several ways, such as reducing native habitat, making it challenging for species to survive, and removing native vegetation, which in turn reduces carbon uptake through photosynthesis and accelerates soil decomposition. This process contributes to the release of more greenhouse gases and impacts ecosystems and biodiversity.

How does pollution affect the environment and human health?

Pollution comes in various forms, such as air and water pollution, and has significant impacts on both human and ecological health. Polluted air, water, and land create a breeding ground for harmful chemical and biological agents that negatively impact human health, facilitate the spread of diseases, and damage ecosystems. Pollution also contributes to issues such as the depletion of the ozone layer and global warming.

What steps can be taken to combat global environmental change?

Some measures to combat global environmental change include improving fuel efficiency in power plants and vehicles, developing and implementing renewable energy and non-fossil fuel alternatives, halting deforestation, supporting and undertaking tree planting (afforestation), reducing air pollution, and promoting sustainable development and resource management practices. International cooperation and policy implementation are also crucial for addressing global environmental challenges.