Assignment Code: MEV-022/TMA/2022-23

Course Code: MEV-022

Assignment Name: Impacts of Climate Change

Year: 2022-2023

Verification Status" Verified by Professor

Answer any five questions. All question carries equal marks. The marks for each question are indicated against it within brackets on the right-hand side.

Please write all answers in your own words.

Q 1. Explain the impacts of climate change on ocean ecosystem. (20 marks)

Ans) We are just starting to understand the magnitude of the changes that are being caused by climate change to ocean ecosystems, despite the fact that these changes are having a significant impact. Despite the vast capacity of the ocean to absorb heat and carbon dioxide, the warming trend appears to be accelerating. Since 1950, more than 90 percent of the warming that has occurred on Earth has been observed in the oceans.

As a direct consequence, climate change has led to an increase in the ocean's stratification, as well as shifts in the ocean's current regimes, the expansion of oxygen-depleted zones, changes in the geographical ranges of marine species, and shifts in the seasons during which species communities are actively growing, as well as shifts in the diversity and abundance of species communities. Warming of the atmosphere is leading to the melting of ice and glaciers on land, which in turn is leading to an increase in sea level, which in turn is having significant impacts on shorelines (including coastal erosion, saltwater intrusion, and habitat destruction), as well as on coastal human settlements.

Changes in Physical Properties

Alterations in the water temperature, oceanic circulation, rising sea levels, and an increase in the intensity of storms are all examples of changes in the physical properties of the ocean.

Changes in Water Temperature

More than 80 percent of the heat that has been added to the system of the Earth as a result of climate change has been absorbed by the ocean, but it is taking a toll on the ocean. The number of heat waves that occur over oceans has increased by more than 50 percent in a span of time that is less than a century long.

Melting of the Polar Ice

The melting of polar ice is being attributed to a rise in the temperature of the atmosphere, which has also led to notable shifts in the coverage and thickness of sea ice in the Arctic over the past 30 years. Studies have shown that there has been an average decline of 11 percent in the extent of sea ice between 1980 and 2008, with evidence of a recent acceleration. Furthermore, there has been a reduction of 50 percent in the thickness of sea ice between 1980 and 2008 (28 years), bringing it down to 1.75 metres.

Rising Sea Levels

Monitoring programmes for sea levels and other types of data point to rising sea levels in the present day in comparison to the previous two thousand years. When the temperature of the sea's water rises, the sea will expand. In a similar vein, the melting of glaciers and polar ice leads to an increase in the level of the sea. The draining of wetlands, the extraction of groundwater, the construction of dams, and changes in land use are all human activities that contribute to the rise in sea level. Because 41% of the world's population lives within 100 kilometres of the coast, rising sea levels pose a significant threat to this area. The International Panel on Climate Change (IPCC) has predicted that sea levels will be higher in 2100 than they are currently rising at a rate of 3.1 millimetres per year. However, these rates do not remain constant across the globe and show significant spatial variability.

Changes to the Ocean’s Major Current Systems

Oceanic currents will be affected and altered by changes in ocean temperatures and wind patterns. Because ocean currents play an important role in maintaining Earth's climate, changes in the ocean's major current systems will have a significant impact on global climate. Oceanographers have observed changes in the North Atlantic Ocean currents as sea surface temperature and ice melting have increased. The Atlantic plays an important role in the regulation of global ocean currents.

Currents in the Southern and Pacific oceans are created by the sinking of large amounts of cooler water in this ocean. As a result, a slowing of the currents in this region has global implications. The entire Northern Hemisphere cools, Indian and Asian monsoon areas dry up, North Atlantic storms intensify, and less ocean mixing means less plankton and other sea life. It would also cause the southern hemisphere to warm. The IPCC concluded that if temperatures rise by 4 degrees Celsius and GHG emissions continue to rise, circulation could be reduced by up to 54 percent by the end of the century.

Oceans play an important role in mitigating the effects of climate change, but this property is also slowly destroying and altering the marine ecosystem. The impact of climate change on oceans has been noted in terms of rising ocean temperatures and their associated effects on fish distribution and productivity, which has direct and indirect impacts on the livelihoods of people who rely on fisheries. Apart from wreaking havoc on marine species, the degradation of coastal and marine ecosystems such as coral reefs endanger the tourism industry and economy's long-term viability. As a result, it is critical that we develop a thorough understanding of the ocean's vast secrets and act quickly so that this abundant climate change mitigation system that supports millions of people worldwide can continue to function and provide services.

Q 2. Explain the impacts of climate change on agriculture. (20 marks)

Ans) Agriculture is a major source of GHGs which contribute to the greenhouse effect and climate change. However, the changing climate is having far reaching impacts on agricultural production, which are likely to challenge food security in the future.

Several biotic and abiotic stresses, including climate change, are having a negative impact on agriculture. One of these is that agriculture is being negatively affected. The climate continues to be one of the most important factors influencing Indian agriculture. The effects of climate change on India's agricultural sector are extremely detrimental. The performance of agriculture is closely related to poverty levels due to the fact that approximately 75 percent of the population lives in rural areas. Regarding the effects of climate change on crop yields, overall food production, and welfare, rice, and wheat, the two most important cereal crops, have been singled out as the primary focus of attention.

The following was determined by running simulations for each crop at four distinct locations under a variety of different climate change scenarios:

1. The yields of both crops – rice and wheat – would decrease with a rise in temperature levels and increase with a rise in precipitation.

2. Higher CO2 concentrations in the atmosphere would have beneficial effects for both crops by increasing the rate of photosynthesis, radiation use efficiency, and water use efficiency.

3. Increased CO2 levels would be more favourable for wheat than for rice.

In general, the results of the simulation indicate that an increase in temperature is likely to have the following effects:

1.  Larger negative impacts are expected to neutralize positive impacts, if any, Livelihood of CO2 fertilization.

2. Net yield losses in rice under irrigation could be some 13%–22%, compared with losses of 16%–34% for wheat.

3. Quality of products such as cotton, fruits, vegetables, tea, coffee, aromatic and medicinal plants, and the nutritional quality of cereals and pulses may be moderately affected.

4. Decline in grain protein content in cereals could partly be related to increasing CO2 concentrations. Wheat yields in central India are likely to suffer by up to 2% in the pessimistic scenario, but there is also a possibility that these might improve by 6% if the global change is optimistic.

5. Changes in soil water induced by global climate change may affect all soil processes and, ultimately, crop growth.

6. An increase in temperature would also lead to increased evapotranspiration, which may result in the lowering of the groundwater table at some places.

7. Increased temperature, coupled with reduced rainfall, may lead to upward water movement, leading to accumulation of salts in upper soil layers.

8. A rise in sea level associated with increased temperatures may lead to salt-water ingression in the coastal lands, making them unsuitable for conventional agriculture.

9. An increase of 1ºC in soil temperature may lead to higher mineralization.

The following effects, which are going to be caused by a rise in temperature, are going to be felt in the agricultural sector:

1. Larger negative impacts are expected to neutralize positive impacts, if any, of CO2 fertilization.

2. Net yield losses in rice under irrigation could be 13%– 22%, compared with losses of 16%–34% for wheat.

3. Quality of products such as cotton, fruits, vegetables, tea, coffee, aromatic and medicinal plants, and the nutritional quality of cereals and pulses may be moderately affected.

4. Decline in grain protein content in cereals could partly be related to increasing CO2 concentrations.

5. Changes in soil water induced by global climate change may affect all soil processes and, ultimately, crop growth.

6. An increase in temperature would also lead to increased evapo-transpiration, which may result in the lowering of the groundwater table at some places; and

7. Increased temperature, coupled with reduced rainfall, may lead to upward water movement, leading to accumulation of salts in upper soil layers.

The climate is probably the single most important factor in determining the patterns of vegetation found across the entire planet, and it has a significant impact on the distribution, structure, and ecology of forest ecosystems. Several studies that looked at the relationship between climate and vegetation came to the conclusion that certain climatic regimes are linked to specific plant communities or functional types. It is therefore reasonable to suppose that shifts in climate will bring about modifications to the structural makeup of forest ecosystems.

Q 3. Explain the impacts of climate change on human health. (20 marks)

Ans) There is a wide range of ways in which weather and climate can have a significant impact on human health. To varying degrees, different people and different communities will be impacted by their level of exposure to the health risks associated with climate change. Exposure to multiple climate change risks can occur simultaneously, which can result in compounding or cascading health effects. Despite the fact that these risks are frequently evaluated separately,

Some of the most fundamental pre-requisites for good health, such as clean air and water, sufficient food, adequate shelter, and freedom from disease, will be profoundly impacted negatively by climate change. The current rate of change in the global climate is faster than at any other time in the history of human civilization, and many of the effects on health will become immediately apparent. The effects of climate change have the potential to slow, halt, or even reverse the progress that has been made against many of these infections.

Possible negative effects on health that cannot yet be quantified include those that are caused by:

1. Changes in air pollution and aero-allergen levels.

2. Altered transmission of other infectious diseases.

3. Effects on food production via climatic influences on plant pests and diseases.

4. Drought and famine.

5. Population displacement due to natural disasters, crop failure, water shortages.

6. Destruction of health infrastructure.

7. Conflict over natural resources.

8. Direct impacts of heat and cold (morbidity).

Surveys have shown that many populations, including those in Australia, China and Italy, place climate change high on lists of threats to their security and well-being.

Changes in Air and Water Quality

An extremely high temperature has the potential to have a significant detrimental effect on human health. In addition, climate change and rising surface air temperatures would lead to an increase in the concentrations of air pollutants, such as the amount of ozone in the troposphere. In addition to this, it is estimated that respiratory and cardiovascular diseases caused by urban air pollution account for over 1.2 million deaths annually in the United States alone.

The incidence of diseases that are transmitted through water has increased as a result of a number of factors, including but not limited to "climate shifts," "water-cooled air conditioning plants," industrial agricultural practises, climate disasters, and so on. Additionally, changes in population demographics, an increase in the percentage of the population that is vulnerable, as well as shifts in human behaviour, are all primary contributors to the human health burden.

Allergens/Air Pollutants

The term "pollution" refers to a phenomenon that occurs as an inevitable result of the presence of human beings and the activities they engage in. At this point in time, pollution in the air has become more insidious and does not respect geographic or political boundaries. One of the contemporary issues affecting people's health all over the world is pollution in the air.

Effect of Air Pollution

Both immediate and long-term consequences can be attributed to exposure to air pollution on a person's health. The respiratory system is the first to feel the effects of the exposure. The condition that develops as a result is known as acute bronchitis. If there is a significant amount of pollution in the air, it could even cause an immediate death from suffocation. The human respiratory and cardio-respiratory systems both suffer multiple adverse effects as a direct result of exposure to air pollution. In terms of the socioeconomic implications, air pollution has a negative impact on a variety of factors, including physical infrastructure, plant, and animal life, and so on.

Spread of Disease-Causing Organisms

Indeed, the interactions between the pathogen, also known as disease-causing organisms, and the host in an environment that is constantly shifting can be quite complicated. Because of the shifting environment, the host and the pathogen are both attempting to adjust their behaviour, and in the subsequent cycle of interactions, the pathogen is also attempting to evolve itself. In addition, climate change and climate variability greatly expand the geographic range of mosquitoes, which in turn increases the length of the breeding season, the number of blood meals that mosquitoes consume, and ultimately the incidence and prevalence of diseases that are transmitted by mosquitoes. In addition, natural disasters brought on by climate change, such as floods, make it more likely for people to contract diseases carried by vectors.

Q 4. Explain the impacts of climate change on forest. (20 marks)

Ans) Alterations in temperature, rainfall, and other aspects of the weather are just some of the ways that climate change can have a direct and indirect impact on the growth and productivity of forests. In addition to this, increased concentrations of carbon dioxide have an impact on the growth of plants. These changes have a multitude of effects on the complexity of forest ecosystems.

The forests of India cover approximately 20 percent of the total land area, which amounts to 64 million hectares. India is known as a megadiverse country. There is a clear and present danger of communities becoming overly dependent on forest resources, given that nearly 200,000 villages are categorised as forest villages. As a result, it is essential to conduct research on the potential effects that climate change will have on forests, as well as to devise and put into action adaptation strategies, in order to preserve biodiversity and protect the livelihoods of people whose lives depend on forests.

The preliminary qualitative assessments of potential climate change impacts on forests in India were based on older GCM (General Circulation Model) outputs of climate change that have been significantly refined. These GCM outputs were derived from earlier climate change projections. Following this, two regional studies were conducted, the first of which focused on the potential effects of climate change on the forests of the state of Himachal Pradesh in the country's north, and the second of which focused on the Western Ghats. According to these studies, there have been moderate to large-scale shifts in the types of vegetation, which may have implications for the loss of forest biodiversity.

The geographical distribution of forests, their composition, and the amount of production they provide are all significantly influenced by climate. As a result, alterations in climate may cause changes in the structure and productivity of forest ecosystems. Non-timber forest products (also known as NTFPs) account for approximately forty percent of the total official revenues generated by forests and fifty-five percent of the workforce employed in forest-based industries. About 200 million people in India are directly or indirectly reliant on the country's forest resources for their livelihoods.

The total amount of potentially extractable NTFPs is expected to result in the following:

1. Increase in expanding evergreen and moist deciduous forest types.

2. Decline in the dry deciduous, dry thorn, and montane forest areas.

GCM (Global Climate Model) projections for India show an increase in precipitation of up to 30% for the north-eastern region, as well as a relatively moderate increase in temperature of about 2oC between 2041 and 2060. This could increase the frequency of flooding in the Brahmaputra basin, favouring the preservation of moist grasslands in the region.

Climate change impacts on forests have serious consequences for people who rely on forest resources for a living. India is a mega-biodiversity country with forests covering more than one-fifth of its land area. With nearly 173,000 villages classified as forest villages, India's communities rely heavily on forest resources. India has a large afforestation programme of over 1.32 million hectares per year and more area is likely to be afforested under programmes such as the 'Green India Mission' and the 'Compensatory Afforestation Fund Management and Planning Authority' (CAMPA).

As a result, it is critical to assess the likely impacts of projected climate change on existing forests and afforested areas, as well as develop and implement adaptation strategies to improve forest resilience to climate change. It is very timely that the Government of India, through the NAPCC (National Action Plan on Climate Change), has proposed reforesting more than 6 million hectares of degraded forested lands.

Forests are expected to benefit significantly (in terms of NPP) in the northern parts of the Western Ghats and the eastern parts of India, while they are negatively impacted in western and central India. As a result, afforestation, reforestation, and forest management in the northern Western Ghats and eastern India may benefit from carbon sequestration.

As a result, a species36 mix that maximises carbon sequestration should be planted in these areas. Hardy species that are resilient to increased temperature and drought risk, on the other hand, should be planted in the forests of western and central India, and care should be taken to further increase forest resilience. This can be accomplished by planting mixed species, connecting forest fragments, developing effective pest and fire management strategies, and conducting anticipatory plantation activities.

Q 6. Explain the impacts of climate change on biodiversity. (20 marks)

Ans) The relationship between a changing climate and the loss of biodiversity is now widely acknowledged to exist. However, biodiversity, through the ecosystem services it supports, also makes a significant contribution to both the mitigation and adaptation of climate change.

Climate change has a negative impact on biodiversity, which in turn has negative consequences for the well-being of humans. Consequently, addressing climate change requires both the preservation of biodiversity and the management of it in a sustainable manner.

The alterations to the environment that are being caused by climate change are causing natural habitats and species to be disrupted in ways that are only now starting to become apparent. There is evidence that rising temperatures are having an effect on biodiversity, while shifting patterns of rainfall, extreme weather events, and ocean acidification are putting additional stress on species that were already in danger as a result of other human activities. It is anticipated that the danger posed by climate change to the world's diverse biological communities will worsen, despite the fact that healthy ecosystems have the ability to mitigate the negative effects of climate change.

Combinations of different kinds of life and the ways in which they interact are what are meant by the term biodiversity. These interactions take place on several different levels, including the genetic, species, and ecosystem levels, and they are influenced by the surrounding physical environment. Because of the many different kinds of habitats and the many different kinds of microclimates, the mountain ecosystem is home to an exceptionally high level of biological diversity. Changes in climate have already had significant and measurable effects on almost all ecosystems and ecological processes, including shifts in the distribution of species, the timing of biological behaviour, the composition of assemblages, ecological interactions, and the dynamics of communities.

Some of the well-recognized impacts of climate change on biodiversity are enumerated as under:

Shifts in Distribution of Plants and Animals

Alterations in the patterns of climate could, at the most fundamental level, cause natural distribution limits for species or communities to shift. It may be possible for communities or species to relocate in response to shifting environmental conditions if there are no barriers preventing their movement. As a result of changes in the average temperature, vegetation zones might migrate to more northerly latitudes or to higher altitudes atop mountains. At higher latitudes, where temperatures are forecasted to rise more than they will be getting closer to the equator, movements are going to be more pronounced.

Rapid Changes and Adaptation

The rates of climate change and the adaptation of different species will be very important, and these rates will vary on a regional and even a local scale. Some sedentary species, such as large tree species that are found in mountainous settings, may have maximum rates of spread that are slower than the predicted rates of change in climatic conditions. It is highly likely that this will result in the local extinction of these species.

Species Interaction

In many instances, additional complications are arising as a result of the complexity of species interactions and the different sensitivities that different species have to shifting environmental conditions. Certain species have the potential to rapidly adapt to new environmental conditions and may engage in new forms of competition with other species.

Invasive Species

Animals have been brought from one part of the world to another by humans, who then either ate them, competed with them, hybridised with them, or brought pathogens or parasites with them. The conditions that are created as a result of changes in the global climate are ones that may be suitable for certain invasive species to become established in new areas.