Environment GS Paper 3 by Dr. Chetan Kaushik

Model Answer

Biodiversity Threat and Conservation

Question #1. “Human induced environmental degradation in ongoing Anthropocene epoch is a major reason behind Sixth Mass Extinction.” Critically Analyze.

Approach

1. Briefly discuss Anthropocene Epoch, advent of human beings and sixth mass extinction.
2. Discuss the factors contributed by anthropogenic activities which led to sixth mass extinction.
3. Discuss effects of mass extinction as multiplier effect and conclude with need for sustainable development.

The current epoch which is signified by the commencement of significant human impact on earth's geology and ecosystems has been termed as Anthropocene epoch. Over 99 percent of all species that ever lived on Earth have gone extinct. Five mass extinctions are recorded in the fossil record. They were caused by major geologic and climatic events. Evidences show that a sixth mass extinction is occurring now which is the result human action.

Reasons behind the current mass extinction

• Habitat Loss: It is considered as the single biggest cause of extinction. The habitats of endemic species have been lost due to agriculture, forestry, mining, and urbanization.
• These anthropogenic activities have disturbed or destroyed more than half of Earth’s land area.
• For Example: More than 99 percent of tall-grass prairies have been lost in USA.
• Introduction of Exotic species:With advent of transportation and communication exotic species of plants and animals have been introduced by humans.
• They may carry disease, prey on native species, and disrupt food webs. Often, they can out-compete native species because they lack local predators.
• Over-harvesting: Over-harvesting of fish, trees, and other organisms has threatened their survival and the survival of species that depend on them.
• Climate Change: Global climate change which has been caused due due to the burning of fossil fuels is a major cause of extinction of few species.
• This is raising Earth’s air and ocean temperatures. It is also raising sea levels. These changes threaten many species.
• Pollution: Pollution, which adds chemicals, heat, and noise to the environment beyond its capacity to absorb them. This causes widespread harm to organisms.
• Overpopulation: Human overpopulation is crowding out other species and capturing their habitats and natural resources.
• Combination of these factors has resulted in decline of certain species of organism at a faster rate. 
• For example, frogs are declining at an alarming rate due to threats like pollution, disease, and climate change.
• Frogs bridge the gap between water and land habitats, making them the first indicators of ecosystem changes. Decline in their species showcases mass extinction of species in an effective way.

Effects of mass extinction

• Imbalance in Food web and food chain:Mass extinction across the globe has led to imbalance in food chain and food webs. It has caused an overall imbalance in the ecosystem.
• One of the major characteristics of the mass extinction is the decline in the numbers of large predators like sharks, lions and wolves which is disrupting Earth's ecosystem.
• It has led to a disruptive food chain as the number of secondary consumers has been rising tremendously.
• For Example:Fewer cougars in the western US state of Utah led to an explosion of the deer population. The deer ate more vegetation, which altered the path of local streams and lowered overall biodiversity. This further may lead to desertification of the region leading to migration and deaths of even deer population.
• Rise in Zoonatic diseases: Species extinction have also resulted in rise in different types of diseases.
• For Example, in Africa, where lions and leopards are being lost to poachers, there is a surge in the number of olive baboons, who are transferring intestinal parasites to humans living nearby.
• Change in diet patterns of living organisms: Loss of original feed stocks due to human intervention has led to adoption of new dieting pattern by certain organisms, which has led to extinction of those organisms whose reproduction rate is low.
• For Example, In the oceans, industrial whaling led a change in the diets of killer whales, who eat more sea lions, seals, and otters and have dramatically lowered the population counts of those species.

Conclusion: Anthropogenic activities with the start of Anthropocene Epoch has added multiplier effects to the environment leading to modifications in the surrounding environment of living organisms in a greater way. This has led to impact on their reproductively and sustainability resulting into species extinction. Sustainable development goals must be adopted at a faster pace to check this extinction.

Climate Change

Question # 2. “From Urban floods, salinization of aquifers, loss of biodiversity, climate migration to thawing of permafrost, climate change has caused multiplier effect on environment.” Elucidate.

Approach

1. Briefly discuss the ‘multiplier effect’ of climate change.
2. Discuss in detail impact of climate change on different anthropogenic activities.
3. Conclude with need to adopt resilience and effective measures to counter climate change.

Climate change has initiated multiplier impact on earth’s ecosystem. It has caused thawing of permafrost and arctic ice which has raised the sea level on one hand and released trapped green house gases into the atmosphere on the other. The released greenhouse gases would again escalate global warming which further intensifies thawing of permafrost and arctic ice-caps. Apart from these, losses of biodiversity, agricultural land, salinization of aquifers e.t.c. has led to migration of human beings as climate migrants. These migrants further accumulate at one place and contribute in unsustainable development, adding more Green House Gases and intensifying the climate change.

Multiplier effect of climate change and impact on humans

• Thawing of Permafrost and melting of ice caps: Climate Change has resulted in thawing of permafrost in peri-glacial regions and arctic regions.
• This has led to release of trapped green house gases such as methane into the atmosphere which in turn will contribute in global warming.
• The ‘Arctic Land Reclamation’ by countries such as Russia due to thawing in permafrost regions has resulted in expansion of agricultural land. It has made Russia from net importer to net exporter of wheat in the world.
• But at the same time agricultural runoff and release of Green House Gases from agricultural practices will intensify the impact of global warming.
• Climate Migration: The rise in sea level has engulfed the agricultural lands and polluted the underground water aquifers. It has also led to salinity of oceans leading to extinction of brackish water fishes and aquatic organisms.
• The loss of livelihood aided by habitat loss has led to climate migration at large scale. These people migrate to urban centers leading to overburden on existing resources of these centers.
• Further, these climate migrants wither settle in sub-urban areas engaged in truck farming or animal husbandry or in slums engaged in small factories which develop around them, dependent upon cheap labour.
• These sites are often congested and emit large amount of pollution in air, water and soil.
• Overpopulation leads to unsustainable urbanization leading to excessive pollution due to heavy traffic and burning of fossil fuels, emission from small factories and dairy farming e.t.c. again adding up to global warming.
• Loss of biodiversity: Climate change has been touted as one of the major reasons behind loss of biodiversity and sixth mass extinction has been driven by it.
• Climate Change leads to decline in native species of plans leading to loss of habitat for animals and loss of natural sink for Carbon-di-oxide.
• Urban Floods and Salinization of aquifers: Sea level rise which has been caused by global warming has led to intrusion of saline ocean water into the water table leading to acute shortage of water in major coastal cities of the globe.
• Further, any change in volume of coastal water of oceans due to heavy precipitation leads to phenomenon of urban floods.

Conclusion
Although many steps have been taken to combat global warming, the global rate of temperature rise has still not been countered effectively. In 2020, the commitment period of ‘Paris Climate Deal’ has started but the rate of emission of Green House Gases can only be altered when countries adopt resilience and effective measures and commit themselves towards ‘Intended Nationally Determined Contribution (INDC) targets effectively. Sustainable Development is the only way to combat the menace of climate change on earth.