Impact of Global Warming:

Increased Frequency and Severity of Heat Waves:

     The extraordinary heatwave of 2021, which resulted in the loss of hundreds of lives in British Columbia (South-Western Canada) and the adjacent states of Washington and Oregon (North-Eastern US), represents the most recent occurrence in an increasing series of severe weather phenomena linked to global warming. Recent deadly wildfires in Australia (2019-20), California (2020), and Siberia have also been attributed to such extreme heat conditions.

Heat Wave:

A heat wave refers to an extended duration of unusually high temperatures.

• • The India Meteorological Department (IMD) officially designates a heat wave when the observed maximum temperature reaches 45°C or higher, irrespective of the typical maximum temperature.
  • Heat waves can result from the displacement of Jet Streams (meandering Rossby Waves in temperate regions leading to Heat Domes, as detailed in Physical Geography > Page 236), local hot winds such as loo (which impact the Gangetic Plains Region), and human-induced factors like global warming.

Global Warming and Heat Waves:

• • Since 1900, the global average temperature has risen by approximately 1.3°C, while in India, it has exceeded 2°C. As emissions persist in increasing, India is likely to experience more frequent heat waves compared to other regions of the world.
  • Research conducted by the Indian Meteorological Department and the Indian Institute of Tropical Meteorology in Pune indicates a notable rise in both the frequency and intensity of heatwaves in India over the past thirty years.
  • The repercussions of these heatwaves extend beyond urban areas, although cities exacerbate the situation through the creation of Urban Heat Islands.

Effects of Heat Waves:

• • Heat-related illnesses, such as sunstroke (characterized by body temperatures exceeding 40°C), can lead to vital organ failure.
  • In 2015, heat waves in India were responsible for over 2,300 fatalities. Similarly, a record heat wave in July 2021 resulted in the deaths of more than 500 individuals in western Canada.
  • Additionally, heat waves adversely affect human productivity, particularly mental health, as optimal body functioning occurs within a narrow temperature range of 36-37.5°C.
  • The economic implications are significant, as there is an increased reliance on cooling devices, which inadvertently contributes to a positive feedback loop that exacerbates global warming: heat waves necessitate more cooling appliances, leading to higher emissions and consequently more severe heat waves.
  • Furthermore, ecological repercussions include diminished biological activity and reduced carbon sequestration.
  • One of the most severe outcomes of heat waves in temperate regions is the occurrence of wildfires, as evidenced by the Australian bushfires of 2019-2020 and the wildfires in western Canada in July 2021.

Urban Heat Islands:

     An urban heat island refers to a metropolitan or industrial region that experiences significantly elevated temperatures compared to its adjacent rural areas, despite both regions having the same climatic conditions, primarily as a result of human activities.

Causes Behind Urban Heat Islands:

• • The replacement of natural vegetation and water bodies with heat-retaining materials such as concrete and asphalt, which possess low albedo, leads to diminished evaporation and evapotranspiration.
  • Additionally, the prevalence of high-rise buildings increases the surface area available for heat absorption.
  • The density of vehicles contributes to elevated heat emissions from their engines, while high levels of pollution and greenhouse gases, particularly CO2 from thermal power plants and vehicles, exacerbate the situation.
  • Greenhouse gases, aerosols, and particulate matter effectively absorb outgoing infrared radiation.
  • Furthermore, cooling devices like air conditioners expel heat into the environment.
  • The occurrence of poor monsoons can be attributed to reduced water evaporation from both vegetation and soil.
  • Urban areas experience heat retention at night, a phenomenon that was not as pronounced in the past, primarily due to the influence of air conditioning, pollution, and the close proximity of dense building networks, which contribute to the formation of urban heat islands after sunset.

Marine Heat Waves:

     Marine heatwaves are defined as prolonged periods during which ocean temperatures at specific locations rise to unusually high levels, significantly affecting marine ecosystems and global weather patterns, regardless of the season.

IPCC Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) on Marine

Heat Waves:

• • The current state of the oceans is marked by extraordinary phenomena, including rising temperatures, heightened ocean acidification, marine heatwaves, and an increase in the frequency of extreme El Niño and La Niña occurrences.
  • Coastal communities, small island nations, polar regions, and high-altitude areas are especially susceptible to these changes, facing challenges such as rising sea levels and diminishing glaciers.
  • Additionally, communities in various regions are impacted by severe weather events intensified by the warming of the oceans.

Marine heat waves:

      Over the past forty years, marine heat waves have increased in frequency, occurring twice as often and persisting for longer durations. The report indicates that human activities account for 84 to 90 percent of the marine heat waves observed in the last ten years. Projections suggest that by the year 2081, the occurrence of marine heat waves may escalate by a factor of 20 to 50.

Impact on marine productivity:

• • Marine heat waves have led to extensive coral bleaching, a process from which corals require over 15 years to recuperate.
  • These heat waves diminish the mixing of water layers, thereby reducing the availability of oxygen and nutrients essential for marine ecosystems.
  • In the Pacific Ocean, where water temperatures have been abnormally high, there has been an increase in the proliferation of toxin-producing algae, while simultaneously hindering the development of smaller organisms that are crucial to the oceanic food web.

Impact on weather patterns:

• • The primary factor contributing to marine heat waves is the presence of weak winds. These heat waves could significantly impact global wind patterns and oceanic currents.
  • According to the IPCC report, the Atlantic Meridional Overturning Circulation (AMOC), which is responsible for the northward movement of warm, saline water in the upper Atlantic and the southward flow of colder, deeper waters, has already experienced a decline in strength.

A notable reduction in the AMOC could lead to:

• • a further decline in productivity in the North Atlantic,
  • an increase in storm activity in Northern Europe,
  • diminished summer rainfall in the Sahel region of the Sahara Desert and South Asia,
  • a decrease in the frequency of tropical cyclones in the Atlantic, and
  • a rise in regional sea levels along the northeastern coast of North America, as highlighted in the report.

More severe cyclonic storms:

      The Intergovernmental Panel on Climate Change (IPCC) indicates that there is growing evidence of a yearly rise in the proportion of category 4 and 5 storms, which maintain their intensity by drawing energy from the moisture present in warm ocean waters.

Increased Incidence of Wildfires:

      The rising frequency of wildfires contributes to a self-reinforcing cycle that intensifies global warming.

Australia’s Bushfires are Getting Severe:

• • Australia, which experiences the onset of summer around October, is recognized as the most fire-prone continent globally.
  • This is primarily attributed to its status as the driest inhabited continent, with nearly 70% of its land classified as arid or semi-arid, receiving an average annual precipitation of less than 35 cm.
  • The majority of Australia’s forested areas are located in the northern and eastern regions, where bushfires are a common occurrence each summer.
  • However, recent years have seen an escalation in the severity of these fires, largely driven by climate change.
  • In 2020, Australia faced its most severe drought and heat waves in over fifty years, leading to catastrophic wildfires that had a devastating impact on wildlife, resulting in the deaths of thousands of koalas.

Criticism of Australia’s climate policy:

       Approximately one-third of the world’s coal exports originate from Australia, which is responsible for 7% of global carbon emissions. The nation stands as the foremost exporter of coal and liquefied natural gas globally. The Australian government has staunchly supported its coal sector in the face of opposition from environmental advocates. Furthermore, Australia has faced scrutiny for its approach of counting carbon credits under the Kyoto Protocol rather than implementing new measures to achieve its emissions reduction goals.

Wildfires and Zombie Fires Have Reached the Tundra:

• • Wildfires in the permafrost regions of Siberia, located south of the Arctic, are relatively common occurrences.
  • However, in 2020, fire activity was observed significantly north of the Arctic Circle in the tundra, an area typically not associated with extensive wildfires.
  • This anomaly can be attributed to the unprecedented desiccation of tundra flora, including mosses, grasses, and dwarf shrubs.
  • Furthermore, the phenomenon of ‘zombie fires’ is increasingly prevalent in the formerly frozen tundra regions north of the Arctic Circle.
  • A zombie fire, also referred to as a holdover fire, is characterized by its ability to smolder beneath the surface, consuming carbon-rich peat without producing visible flames, often lingering from a previous growing season.

Concerns:

• • The occurrence of wildfires and unprecedented high temperatures may transform the carbon sink into a carbon emitter.

Shrinking Cryosphere:

• • The cryosphere encompasses regions of snow and ice that experience temperatures below 0°C for a portion of the year.
  • This includes continental ice sheets located in Greenland and Antarctica, ice caps, glaciers, snowy regions such as the Alps and Himalayas, permafrost found in Siberia, as well as frozen sections of oceans, rivers, and lakes.
  • Furthermore, an IUCN study indicates that glaciers in nearly half of the natural World Heritage sites, including the Khumbu Glacier in the Himalayas, are at risk of complete disappearance by the year 2100 if current emission levels persist.
  • The research forecasts the extinction of glaciers in 21 out of the 46 natural World Heritage sites that contain glaciers.

Role of Cryosphere:

• • Snow and ice exhibit the highest albedo, reflecting solar heat and influencing the heat budget.
  • Glaciers and elevated snow-capped mountains provide essential freshwater resources to various regions globally.
  • The cryosphere is particularly responsive to climatic variations, functioning as the Earth’s historical record, as layers of ice accumulate over time.
  • Analyzing the vertical ice column is crucial for comprehending historical global climate changes.

Consequences of Shrinking Cryosphere (Glaciers):

• • The increasing scarcity of water resources has led to conflicts between nations, while the degradation of ecologically significant coastal wetlands poses a serious threat to biodiversity.
  • Additionally, the submergence of major coastal cities has resulted in distress migration among local populations, particularly affecting Small Island Developing States that are among the first to experience the adverse effects of climate change.
  • Furthermore, significant alterations in weather patterns are anticipated, and the salinization of groundwater in coastal areas will exacerbate the situation.
  • The irregular melting of glaciers is expected to diminish hydroelectric power generation, thereby heightening reliance on fossil fuels.
  • Lastly, the ongoing loss of habitats is contributing to the alarming decline of animal populations, pushing numerous species closer to the brink of extinction.

Vegetation Change:

• • The thawing of snow is expected to lead to an increase in arable land in high-latitude regions due to the decrease in frozen terrain.
  • Conversely, coastal arable land is anticipated to diminish as a consequence of rising sea levels and the inundation of saline waters.
  • Additionally, the transformation of tundra into swamps will result in a reduction of forested areas, thereby diminishing carbon sinks, while the thawing of permafrost will expose subsurface carbon reserves.

Surge-Type Glaciers and Disasters:

       Surge-type glaciers are characterized by their notable increase in both volume and length over time, which contrasts sharply with the prevailing trend of significant shrinkage observed in the majority of glaciers. Unlike their more stable counterparts, surging glaciers experience irregular flow patterns, marked by cyclical instabilities that prevent a steady movement. The dynamics of these glaciers pose a considerable risk, as they can lead to devastating glacial lake outburst floods, particularly in the context of climate change and global warming, which can trigger their sudden collapse.

New Sea Routes in The Arctic region:

       The Arctic Region is experiencing a rate of warming that is twice that of the global average. As a result of the melting ice, the Northern Sea Route (NSR), which links the North Atlantic to the North Pacific via a shorter polar arc, is gradually becoming more navigable. Projections indicate that this route may be entirely free of ice during the summer months by the year 2050.

New shipping routes:

• • The emergence of the Arctic region offers significant commercial and economic prospects, especially in sectors such as shipping, energy, fisheries, and mineral extraction.
  • Notably, the potential for commercial navigation via the Northern Sea Route (NSR) is particularly appealing, as it could reduce the travel distance from Rotterdam to Yokohama by 40 percent in comparison to the traditional Suez Canal route.

Access to unexploited resources:

       It is estimated that unexplored oil and natural gas reserves constitute 22% of the world’s untapped resources, predominantly located in the Arctic Ocean, particularly in the Barents Sea region. Additionally, Greenland is home to significant mineral deposits, containing approximately 25% of the global reserves of rare earth elements.

Challenges associated with the new opportunities:

• • The processes of mining and deep-sea drilling entail significant financial expenditures and pose considerable environmental hazards.
  • In contrast to Antarctica, the Arctic does not function as a global commons; it lacks a comprehensive treaty framework. Instead, the United Nations Convention on the Law of the Sea (UNCLOS) provides the primary legal structure governing the region.
  • A substantial portion of the Arctic is under the jurisdiction of the five coastal nations—Russia, Canada, Norway, Denmark (Greenland), and the United States—allowing them to exploit newly discovered resources, which may lead to renewed territorial disputes.

Arctic (or polar) Amplification (PA):

• • The phenomenon known as Arctic Amplification refers to the disparity in warming rates between the polar regions and the tropics.
  • This indicates that the Arctic is experiencing a more rapid increase in temperature compared to other global regions. Specifically, from 1971 to 2019, the average annual temperature in the Arctic rose by 3.1 degrees Celsius, in stark contrast to the global average increase of only 1 degree Celsius.
  • Arctic Amplification occurs as a result of alterations in the Net Radiation Balance, which is marginally elevated in the Arctic compared to tropical regions.
  • The Net Radiation Balance represents the equilibrium between incoming solar energy and outgoing energy at the uppermost layer of the atmosphere.

The accelerated warming of the Arctic can be attributed to several interrelated factors.

• • One significant contributor is the change in albedo, which is primarily driven by the melting of polar ice at an alarming rate of 13% per decade.
  • Ice possesses a high albedo, reflecting a substantial amount of sunlight, whereas the land and ocean exhibit lower albedo values.
  • As the ice diminishes, it exposes darker surfaces that absorb more sunlight, leading to increased warming.
  • Additionally, the melting sea ice facilitates the release of greenhouse gases from thawing permafrost and frozen methane deposits on the ocean floor, further exacerbating the warming phenomenon.
  • Furthermore, the Arctic experiences a more pronounced amplification of warming compared to Antarctica due to its unique geographical characteristics; the Arctic is an oceanic region covered by seasonal sea ice, while Antarctica is a landmass with a more stable ice cover.
  • Notably, the Antarctic continent has not experienced significant warming over the past seventy years, despite rising greenhouse gas concentrations in the atmosphere.
  • The ramifications of Arctic warming are profound, with the most immediate consequence being global sea-level rise.
  • The thawing of Arctic permafrost poses serious risks to the global climate system, as it releases substantial amounts of carbon dioxide and methane, which can trigger further warming through positive feedback mechanisms.
  • The implications of Arctic amplification extend beyond the polar regions, significantly influencing mid-latitude climates and increasing the frequency of extreme weather events.
  • This influence manifests through the weakening of the tropospheric jet stream, which can lead to unusual and severe weather patterns, as well as the destabilization of the stratospheric polar vortex, resulting in further extreme weather occurrences in mid-latitude regions.

Warming Arctic Ocean Increasing Snowfall in Siberia:

      The warming of the Arctic Ocean has led to an increase in the rate of evaporation, resulting in a greater amount of moisture being present in the Arctic atmosphere. This heightened moisture subsequently travels towards northern Eurasia, contributing to a rise in snowfall, especially in the region of Siberia.

Sea Level Change:

     Changes in sea level refer to the variations in the average sea level that occur over extended periods. Typically, seasonal fluctuations of approximately 5 to 6 centimeters are recorded annually.

Processes that cause Change in Sea Level:

• • Eustatic changes refer to alterations in sea level that arise from variations in the volume of ocean water, which can be influenced by phenomena such as global warming leading to the melting of ice sheets, resulting in a rise in sea level, or the occurrence of ice ages that cause a decrease in sea level.
  • Additionally, the volume changes in mid-oceanic ridges also contribute to these eustatic fluctuations.
  • Tectonic changes, on the other hand, are associated with shifts in land elevation. Isostatic changes occur when there is a gain or loss of weight on the Earth’s crust; for instance, during ice ages, the weight of glacial ice causes land to sink, whereas the removal of this ice leads to the uplift of landmasses.
  • Furthermore, epeirogenic movements involve large-scale tilting of continents, which can result in one section of a continent rising while another sinks, creating an illusion of rising sea levels.
  • Lastly, orogenic movements, which are responsible for mountain formation, can lead to the development of high mountain ranges and an apparent decrease in sea level.

Short-term sea level change:

• • The density of marine water is influenced by both temperature and salinity, with lower temperatures and higher salinity levels resulting in increased seawater density and consequently a reduction in sea level.
  • Additionally, atmospheric pressure plays a significant role, as lower pressure conditions can lead to elevated local sea levels, exemplified by phenomena such as storm surges.
  • Furthermore, the velocity of ocean currents affects sea level; for instance, fast-moving currents that follow a curved trajectory can create a notable rise in sea level along their outer edges, with observed differences reaching up to 18 centimeters along the current’s axis.
  • Moreover, the formation of ice during winter months contributes to a decrease in sea level, as ocean water becomes trapped in the ice caps of both the northern and southern hemispheres.
  • Lastly, the accumulation of water along windward coasts results in localized increases in sea level, particularly evident in regions such as South and East Asia during the monsoon season, when air masses drive water towards the coast.

Long-Term sea level change:

• • Over the past century, human-induced global warming has led to the thermal expansion of ocean waters, resulting in a sea level increase of approximately 10 to 15 centimeters.
  • Additionally, the melting of Antarctic ice sheets, which has accounted for about 3 percent of their total ice volume, has further contributed to the rise in global sea levels.
  • It is important to note that significant alterations in global sea levels, potentially exceeding 100 meters, would only occur if the major ice sheets were to completely melt or if there were considerable changes in the volume of the world’s mid-oceanic ridges.

Significance of Understanding Sea Level Changes:

• • This research offers crucial insights into historical climate variations, facilitates the estimation of tectonic uplift rates during previous geological epochs, and evaluates the viability of coastal regions for industrial and agricultural initiatives.
  • Furthermore, it plays a significant role in safeguarding low-lying nations through the construction of coastal dykes and embankments.
  • The mapping of regions susceptible to storm surges and recurrent flooding is rendered feasible, and by pinpointing areas that may face submersion in the foreseeable future, it enables the strategic establishment of tidal power generation facilities in appropriate sites.

Sea Level Rise and Coastal Flooding:

• • The IPCC report indicates that if greenhouse gas emissions continue to rise significantly, sea levels may increase by 60 to 110 centimeters.
  • This poses a serious threat to urban populations, as over half of the world’s inhabitants reside in cities, many of which are situated on low-lying coastal areas and islands.
  • The economic repercussions of extreme flooding are projected to escalate dramatically, with losses expected to increase by 166 times by the year 2050.
  • Current estimates reveal that approximately 300 million individuals, rather than the previously estimated 80 million, are living in regions that fall below the annual coastal flood line.
  • A significant majority, nearly 80 percent, of these individuals are located in countries such as China, Bangladesh, India, Vietnam, Indonesia, and Thailand, with China alone accounting for 43 million people.
  • Major cities, including Bangkok, Hong Kong, Shanghai, Taizhou, Surabaya, Dhaka, Mumbai, Ho Chi Minh City, and Osaka, will see millions of residents at risk of flooding as they find themselves within designated flood zones.

Vulnerable Areas in India:

• • By the year 2050, approximately 36 million individuals residing along the coastlines of India will inhabit areas that are projected to be submerged below the annual flood level, thereby increasing their vulnerability to flooding.
  • Cities such as Bhuj, Jamnagar, Porbandar, Surat, Bharuch, and Mumbai are particularly at risk due to rising sea levels.
  • Additionally, the eastern coastline, especially in West Bengal and Odisha, faces significant threats from these environmental changes.

Small Island Developing States are the Biggest Losers:

• • Small Island Developing States (SIDS) refer to a category of islands that are geographically isolated, face significant environmental threats, particularly from climate change, and are typically characterized by their small land area.
  • This group was officially acknowledged as a unique subset of developing nations during the United Nations Conference on Environment and Development held in June 1992, commonly known as the 1992 Earth Summit.
  • The majority of these islands are composed of coral and are situated on shallow atolls, rendering them particularly susceptible to the impacts of rising sea levels.

Barbados Programme of Action (1994):

      The United Nations Programme of Action for the Sustainable Development of Small Island Developing States, commonly known as the Barbados Programme of Action (BPOA), serves as a pivotal policy framework that tackles the economic, environmental, and social challenges encountered by these islands, while proposing a comprehensive strategy aimed at alleviating such vulnerabilities. This programme stands as the sole internationally recognized initiative tailored specifically for Small Island Developing States (SIDS).

Mauritius Strategy (2005):

• • The Mauritius Strategy and the Review of the Barbados Programme of Action (BPOA): The Mauritius Strategy was established as a result of a decade-long thorough evaluation of the BPOA, with the objective of enhancing its execution.
  • The Marshall Islands and Nuclear Powers (2016): In 2016, the Marshall Islands initiated legal proceedings against India, Pakistan, and the United Kingdom in the International Court of Justice, alleging their negligence in addressing the nuclear arms proliferation.
  • Addressing Sea Level Rise and Risk Assessment (1987): In response to the challenges posed by rising sea levels, the Oceans and Coastal Areas Programme Activity Centre was founded in 1987 under the auspices of the United Nations Environment Programme (UNEP), with a focus on identifying countries that are particularly vulnerable to the threat of submersion.

Regional Sea Level Rise (SLR):

        Worldwide, 68% of areas are susceptible to coastal flooding, with more than 32% of this vulnerability linked to regional sea level rise (SLR). It is important to note that SLR is not consistent globally; for example, the gravitational influence of polar ice sheets results in varying impacts on sea levels in different regions, leading to instances where regional SLR may exceed or fall short of the global average SLR.

The Growing Threat of Sea Level Rise (SLR):

• • Cities frequently identified as vulnerable to climate change include Guangzhou, Jakarta, Miami, and Manila.
  • In 2019, President Joko Widodo of Indonesia declared the relocation of the nation’s capital from Jakarta to East Kalimantan, situated on the less densely populated island of Borneo.
  • The dual challenges of climate change and severe traffic congestion are contributing to Jakarta’s status as the ‘world’s fastest-sinking city,’ with the city subsiding approximately 25 centimeters annually.
  • Similarly, Mumbai faces a dire future; projections indicate that substantial areas of the city may be submerged due to climate change by the year 2050.

Strategies for Mitigating Sea Level Rise (SLR):

• • The Intergovernmental Panel on Climate Change (IPCC) published a Special Report addressing the Ocean and Cryosphere in the context of a changing climate, which emphasized that effectively designed coastal protection measures could significantly mitigate anticipated damages while also proving to be economically viable for urban and densely populated regions.
  • In 2014, the Indonesian government initiated a coastal development initiative known as the Giant Sea Wall or ‘Giant Garuda,’ named after the Garuda, a bird from Hindu mythology that serves as Indonesia’s national emblem.
  • Additionally, the Northern European Enclosure Dam (NEED) is a proposed infrastructure project aimed at safeguarding 25 million individuals and critical economic areas in Europe from the threats posed by rising sea levels attributed to climate change.
  • This ambitious plan entails the construction of two dams with a total length of 637 kilometers, designed to shield Northern Europe from the inevitable impacts of sea level rise.
  • It has been recognized that various areas, including the Persian Gulf, the Mediterranean Sea, the Baltic Sea, and the Red Sea, could gain advantages from implementing comparable enclosures.

Tropical Cyclones are Becoming More Severe:

       Tropical cyclones necessitate a sea surface temperature (SST) of at least 26.5°C for their formation, whereas the most intense storms demand significantly higher SSTs ranging from 28 to 29°C. Moreover, the occurrence of frequent high-intensity storms has been associated with exceptionally warm SSTs exceeding 30°C.

• • The South Indian Ocean, which once recorded temperatures of 26.5°C, is now witnessing a rise in temperatures reaching between 30°C and 32°C.
  • This increase in oceanic temperatures contributed to the formation of the catastrophic Idai cyclone in March 2019, resulting in over 1,300 fatalities in the southwestern Indian Ocean basin, particularly affecting Southeast Africa.
  • Additionally, regions situated further from the equator are increasingly encountering the critical temperature range of 24°C to 26°C, thereby expanding the potential for tropical cyclone development.
  • These phenomena are further intensified by global climatic influences such as El Niño, the Indian Ocean Dipole, the Southern Annular Mode, and the Madden-Julian Oscillation, all of which are in turn influenced by the overarching effects of global warming.
  • This information is elaborated upon in the PMF IAS Physical Geography course, specifically within the climatology section.

Unusual Timing & High Frequency:

• • The Extremely Severe Cyclonic Storm Fani, which occurred in April 2019, represents the most powerful cyclone to strike India in the month of April in over four decades.
  • This atypical occurrence in April is believed to be linked to the effects of global warming, particularly the anomalous rise in temperatures in the Bay of Bengal.
  • Furthermore, the frequency of severe cyclones in the northern Indian Ocean has seen a significant increase, with occurrences rising from approximately one severe cyclone annually during the peak cyclonic months of May, October, and November, to an alarming rate of about three per year.

The number and intensity of tropical cyclones is increasing in the Arabian Sea:

• • Nearly half of the storms fail to persist over the Arabian Sea, primarily because the west-central and northern regions of the sea experience relatively lower sea surface temperatures (SST) due to the influence of the Findlater/Somali Current, which induces local upwelling.
  • This phenomenon is, however, undergoing a transformation. The Arabian Sea is experiencing a rapid increase in temperature, which is contributing to a rise in cyclone activity and leading to excessive rainfall patterns.
  • This excessive precipitation over the sea results in diminished moisture availability in the monsoon winds, consequently causing reduced rainfall on the mainland. Climate models indicate that approximately 64 percent of the cyclone risk in the Arabian Sea can be attributed to climate change.

Increased occurrence of Severe cyclonic storms:

         Historically, the region experienced one exceptionally severe cyclone approximately every four to five years. Notably, between 1998 and 2013, the Sea witnessed the formation of five extremely severe cyclones. However, in recent times, the Arabian Sea has been increasingly subjected to high-intensity tropical cyclones.

Unusual timing:

      In June 2019, the Arabian Sea experienced a Very Severe Cyclonic Storm named Vayu, which is noteworthy because the climatic conditions during this month typically do not favor the development of severe cyclones, as the onset of the monsoon season usually disrupts such formations.

Changing path:

      Historically, tropical cyclones in the Arabian Sea were primarily confined to the region of Gujarat; however, over the last ten years, the states of Kerala and Karnataka have increasingly experienced susceptibility to these severe weather events.

Deterioration of Carbon sinks:

• • Forests located at high latitudes are more effective at sequestering carbon than tropical rainforests, with approximately one-third of the planet’s soil-stored carbon found in taiga and tundra regions.
  • The melting of permafrost, a consequence of global warming, results in the release of carbon in the forms of carbon dioxide and methane.
  • In the 1970s, the tundra functioned as a carbon sink, absorbing more carbon than it emitted; however, it has transitioned into a carbon source in contemporary times, primarily due to the effects of global warming, which creates a positive feedback loop that exacerbates the situation.

Carbon Dioxide Fertilization:

• • The vegetated areas of Earth have experienced a notable increase in greenness, primarily attributed to elevated levels of atmospheric carbon dioxide, which enhances the process of photosynthesis.
  • This phenomenon, known as carbon dioxide fertilization, accounts for approximately 70 percent of the observed greening, while nitrogen contributes around 9 percent.
  • Additional factors such as alterations in land cover, variations in precipitation, and changes in sunlight also play a role in this process.
  • However, it is important to note that as plants adapt to the increasing concentrations of carbon dioxide, the benefits of this fertilization effect may wane over time.
  • Consequently, while elevated CO2 levels may yield short-term advantages for plant growth, they pose long-term risks associated with climate change.

Carbon Fertilization is increasing carbon sink on land:

     Annually, approximately 50% of the 10 gigatons of carbon released into the atmosphere due to human activities is temporarily sequestered, with roughly equal contributions from both the oceans and terrestrial vegetation. Research has indicated a growing carbon sink on land since the 1980s, aligning perfectly with the concept of a progressively greener planet.

Climate Migrants:

• • Environmental migrants are individuals who have been forced to relocate as a result of detrimental alterations to their surrounding environment.
  • Specifically, climate migrants are those displaced by the effects of climate change, which include phenomena such as rising sea levels in the Sundarbans, flooding in the Ganges and Brahmaputra river basins, and drought conditions affecting central regions of India, including Vidarbha, Telangana, and Rayalaseema.
  • According to the National Sample Survey Office (NSSO) report from 2007-08, entitled ‘Migration in India’, natural disasters were identified as a significant factor contributing to migration, accounting for approximately 13 out of every 1,000 migrants.
  • The increase in displacement and migration resulting from such disasters has raised alarms regarding the potential for heightened human trafficking, conflicts, and increased strain on available resources.

World Risk Index (WRI) 2020:

• • According to the World Risk Index (WRI) 2020, India was inadequately equipped to confront the realities of climate change, rendering it particularly susceptible to severe natural disasters.
  • The report ranked India 89th out of 181 nations, positioning it as the fourth most at-risk country in South Asia, trailing behind Bangladesh, Afghanistan, and Pakistan.
  • In comparison, Sri Lanka, Bhutan, and the Maldives demonstrated superior resilience in managing extreme disasters.
  • Furthermore, the report highlighted Africa as a region of significant vulnerability, with the Central African Republic identified as the most at-risk nation, followed by Chad, the Democratic Republic of Congo, Niger, and Guinea-Bissau.

High And Low Risk Nations:

        The index indicated that Oceania, which includes the Small Island Developing States (SIDS), is the continent facing the greatest risk, with Africa and the Americas following closely behind. Among the nations, Vanuatu emerged as the one with the highest disaster risk globally, succeeded by Tonga and Dominica. In contrast, Qatar was identified as having the lowest risk level, recorded at 0.31, according to the global index.

Other Impacts:

Economic Losses:

• • The economic repercussions incurred encompass expenditures related to adaptation strategies for climate change, such as relocating from areas prone to flooding to more secure elevations, the costs associated with reconstruction following severe climatic events, and investments in climate change mitigation efforts, including carbon sequestration initiatives.
  • The economic losses attributed to the release of one ton of carbon dioxide into the atmosphere are referred to as the social cost of carbon, quantified in monetary terms.
  • In India, the estimated social cost of carbon emissions is notably the highest globally, at $86 per ton of CO2, indicating that the Indian economy incurs a loss of $86 for each additional ton of CO2 emitted.
  • The United States follows, with an estimated economic damage of $48 per ton of CO2 emissions.

Ocean Deoxygenation:

• • The phenomenon of ocean deoxygenation refers to the increasing prevalence of oxygen minimum zones (OMZs) across the global oceans, primarily driven by human-induced carbon dioxide emissions.
  • These OMZs typically occur in regions where a combination of physical factors, such as ocean stratification, and biological factors, including reduced photosynthesis, leads to the formation of anoxic zones characterized by diminished oxygen levels.
  • Additionally, the warming of ocean waters contributes to deoxygenation, as warmer temperatures reduce the solubility of oxygen and promote stratification driven by temperature variations.

Effects of deoxygenation of oceans:

        The depletion of oxygen in oceanic environments leads to increased acidity, which adversely affects shellfish by degrading their shells. Additionally, there is a significant decline in the cycling of vital elements such as carbon, nitrogen, and phosphorus, which are crucial for sustaining various life forms. This ecological imbalance results in substantial fish mortality, primarily due to the diminished availability of phytoplankton, their primary food source.

Biodiversity Loss:

      The bleaching of coral reefs, often referred to as the rainforests of the ocean, along with the decline of plankton populations resulting from rising sea temperatures, will have detrimental effects on marine food chains, leading to a significant reduction in marine biodiversity.

Food and Health Security at Risk:

• • Climate change significantly influences agricultural productivity by altering irrigation practices, sunlight exposure, and the incidence of pests.
  • The increasing frequency of extreme weather events such as droughts, floods, storms, and cyclones is expected to heighten the variability in agricultural output.
  • Additionally, rising temperatures will lead to a greater demand for fertilizers, which in turn will elevate greenhouse gas emissions, ammonia volatilization, and the overall costs associated with crop production.
  • While a moderate increase in mean temperatures (ranging from 1 to 3°C) may enhance crop yields in temperate regions, it is anticipated that crops in lower latitudes will suffer adverse effects.
  • Nonetheless, the benefits of temperature increases in temperate areas may be negated by the natural disasters linked to global warming.
  • Furthermore, the scarcity of freshwater during droughts and the contamination of water supplies during floods pose significant hygiene challenges, thereby increasing the incidence of diseases such as cholera and diarrhea.
  • The proliferation of diseases, including malaria, in tropical regions will further strain healthcare systems.