Geography - 4 | Current Affairs & Hindu Analysis: Daily, Weekly & Monthly - UPSC PDF Download

Influence of Wind Shear on Hurricanes

Why in News?

Recently, the concept of wind shear has gained increased attention due to its crucial role in determining whether a storm intensifies into a destructive hurricane.

What is Wind Shear?

• About: Wind shear is a meteorological phenomenon characterized by a sudden change in wind speed and/or direction over a relatively short distance.
• Types:
  • Vertical Wind Shear: Occurs when wind speed and/or direction change rapidly with altitude. Common examples include low-level jet streams and wind shear associated with thunderstorms.
  • Horizontal Wind Shear: Occurs when wind speed and/or direction changes swiftly over a horizontal distance. For instance, wind may blow from the west at one location and then suddenly shift to the north just a short distance away, often seen with frontal systems and sea breezes.
• Major Causes:
  • Temperature Inversion: On calm nights, warm air near the ground traps cooler air above, resulting in strong vertical wind shear, which can pose hazards for aircraft during takeoff and landing.
  • Thunderstorms: The powerful updrafts and downdrafts within thunderstorms create both horizontal and vertical wind shear, making flying in their vicinity dangerous.
  • Frontal Systems: Boundaries between warm and cold air masses (fronts) lead to rapid changes in wind speed and direction, resulting in horizontal wind shear that complicates aircraft navigation.
• Detection Methods:
  • Low-Level Wind Shear Alert System (LLWAS): A network of ground-based towers equipped with anemometers and wind direction sensors measures wind characteristics at multiple points around an airport.
  • Doppler Radar: Ground-based radars track wind speed and direction to identify wind shear zones.
  • LIDAR: Uses light to detect wind shear, particularly useful for monitoring clear air turbulence.

What are the Effects of Wind Shear on Hurricanes?

About Hurricanes: Hurricanes, also known as tropical cyclones, are violent storms that form over oceans in tropical regions and can cause extensive destruction when they reach coastal areas. Their formation and development hinge on the transfer of water vapor and heat from warm ocean waters to the overlying air, primarily through evaporation from the sea surface. They are referred to by various names worldwide, such as:

• Typhoons in the China Sea and Pacific Ocean
• Tornados in West Africa and the Southern USA
• Willy-willies in north-western Australia
• In the Caribbean and Atlantic Ocean regions.

Effects of Wind Shear on Hurricanes:

• Hurricanes thrive in environments with minimal vertical wind shear, which supports a symmetrical structure and efficient rotation.
• Strong vertical wind shear can disrupt the hurricane's vertical structure, misaligning the storm's top and bottom layers.
• This disruption weakens wind circulation, heat transport, and moisture supply, which are essential for fueling hurricanes.
• Excessive vertical wind shear can potentially dismantle a hurricane entirely.

Other Factors Affecting Hurricane Intensity:

• While vertical wind shear is a significant factor, it is not the sole determinant of hurricane intensity.
• Other critical factors include sea surface temperatures, atmospheric moisture content, and pressure systems, all of which play vital roles in hurricane development and strengthening.
• In certain scenarios, exceptionally warm sea surface temperatures can counteract the effects of increased wind shear, as observed during the 2023 hurricane season.

What is the Influence of EL Nino and La Nina on Wind Shear?

• El Nino's Influence on Wind Shear: During El Nino years, stronger-than-average vertical wind shear is often noted over the Atlantic Ocean during hurricane season. El Nino events are marked by warmer sea surface temperatures in the eastern Pacific and cooler temperatures in the western Pacific, leading to stronger upper-level winds over the Atlantic, which results in increased vertical wind shear. This heightened shear can hinder hurricane development and intensification in the Atlantic basin.
• La Nina's Influence on Wind Shear: Conditions opposite to El Nino, known as La Nina, tend to be more conducive to hurricane development in the Atlantic. During La Nina years, vertical wind shear is typically weaker, allowing for more active hurricane seasons. The record-breaking 2020 Atlantic hurricane season occurred during a La Nina event.

Global Impact of Land Squeeze

Why in News?

A recent study conducted by the International Panel of Experts on Sustainable Food Systems (IPES-Food) focuses on the unprecedented 'land squeeze,' which poses a significant threat to farmers and food production. Land squeeze describes a scenario where the demand for land for various uses—such as agriculture, urbanization, and infrastructure—exceeds the amount of available cultivable land.

What are the Key Highlights of the Report?

• The report warns of a significant "land squeeze" driven by escalating land prices, land grabs, and carbon offset schemes, which endanger farmers and food security.
• Globally, the wealthiest 1% of farms control about 70% of the world's farmland.
• As land becomes scarcer, it is often repurposed from productive agricultural use to other applications, adversely affecting food production.
• From 2008 to 2022, global land prices have doubled, with the most dramatic increases seen in Central-Eastern Europe, where prices have tripled.
• Land acquisitions termed "green grabs," which are ostensibly for environmental initiatives, now account for around 20% of large-scale land deals.
• Over half of the land allocated by governments for carbon removal projects threatens the livelihoods of small-scale farmers and Indigenous communities.
• Carbon offset markets are projected to quadruple over the next seven years.

What are the Key Reasons Behind Land Squeeze?

• Land Grabs: Large-scale land acquisitions by governments, corporations, and speculators are displacing farmers and Indigenous communities, primarily for resource extraction (like mining and logging) or export-oriented agriculture.
• Rising Population and Demands: The growing global population and the high demand for food, feed, fiber, and fuel are intensifying pressure on land availability.
• Shifts in Global Food Production Systems: This involves reallocating vast areas of land towards industrial agriculture, such as Concentrated Animal Feeding Operations (CAFO) and monoculture farming practices.
• Industrial agriculture is characterized by the large-scale, intensive production of crops and animals, frequently utilizing chemical fertilizers and harmful antibiotics.
• Additionally, there is an increased demand for land for biofuels and other non-food uses.

What are the Key Impacts of Land Squeeze?

• Loss of Access and Control for Farmers and Rural Communities: Land grabs and other pressures displace small-scale farmers and Indigenous populations, disrupting their livelihoods and traditional practices.
• Threatens Food Security: A reduction in the number of farmers and the availability of land for food production jeopardizes overall food security, especially for local communities.
• Weakened Bargaining Power: The ownership of land places farmers at a disadvantage when negotiating fair prices from powerful agribusinesses.
• Exacerbated Rural Poverty: Limited access to land constrains opportunities for rural populations, trapping them in a cycle of poverty.
• Environmental Degradation: The focus on large-scale, export-oriented agriculture often results in unsustainable land use practices, such as deforestation, soil depletion, and overexploitation of water resources.
• Loss of Biodiversity: Converting land for mining, infrastructure, and industrial agriculture destroys natural habitats and threatens biodiversity.
• Increased Vulnerability to Climate Change: Soil degradation and loss of natural vegetation weaken ecosystems, making them more susceptible to climate-related shocks.
• Social Unrest and Conflict: Competition for limited land resources can lead to social tensions and conflicts between communities and investors.
• The IPES-Food report indicates that over half of the designated land poses a risk of interfering with the livelihoods of small-scale farmers and Indigenous people.
• Instability and Outmigration: Loss of land and livelihood opportunities drives rural-urban migration, increasing pressure on urban resources and social services.

What are the Recommendations of the Report?

• Halt Land Grabs: Implement policies and regulations to prevent land grabs and prioritize local communities and food security in land use decisions.
• Support Small-Scale Farmers: Essential investments in rural infrastructure, secure land tenure, and access to financing are crucial for empowering small-scale producers.
• Sustainable Land Management: Encourage practices that protect soil health, conserve biodiversity, and secure long-term food production.
• Fair Trade Policies: Reform trade agreements to foster sustainable agriculture and safeguard the livelihoods of small-scale farmers.

Conclusion

The land squeeze is a multifaceted issue that requires a comprehensive solution. By tackling the root causes and supporting small-scale food producers, we can ensure equitable land access, environmental protection, and the establishment of a sustainable food system for the future.

Low Snow Persistence in Hindu Kush Himalayas

Why in news?

The recent report from the International Centre for Integrated Mountain Development (ICIMOD) highlights that snow persistence in the Ganga, Brahmaputra, and Indus basins of the Hindu Kush Himalayas (HKH) has reached unprecedented low levels. ICIMOD, established in 1983, aims to promote a greener, more inclusive, and climate-resilient HKH region.

What are the Findings of the Report?

• The Amu Darya river basin in Afghanistan recorded its lowest snow persistence levels.
• The Helmand River, essential for drinking water in Iran and Afghanistan, experienced a snow persistence decrease of nearly 32% compared to normal.
• China's Yellow River showed an increase in snow persistence by 20.2%, influenced by cold air from the East Asian winter monsoon interacting with moist air from the Pacific Ocean.

India’s Context:

• The report, analyzing data from 2003 to 2024, indicates that the Ganga River basin has its lowest snow persistence in 22 years.
• The Brahmaputra basin recorded a 14.6% reduction in snow persistence compared to normal levels.

Reason Behind Low Snow Persistence

• The study indicates that weakened western disturbances from warmer Mediterranean, Caspian, and Black Seas have led to reduced winter precipitation and snowfall in the HKH region.
• Global warming has exacerbated La Niña and El Niño events, further diminishing snow persistence in the area.
• The 1.5°C global temperature limit outlined in the Paris Agreement may be inadequate for the HKH, which is projected to experience temperature increases above the global average.

Environmental Degradation:

• Environmental degradation in the HKH region, driven by deforestation, overgrazing, unsustainable land practices, and infrastructure development, is leading to severe consequences.
• Key impacts include soil erosion, loss of biodiversity, and water pollution.

The Proliferation of Invasive Species:

• The spread of invasive species, such as Cirsium arvense (Canada thistle) and Trifolium repens (white clover), significantly threatens native Himalayan species.
• This disrupts the delicate ecological balance within the region.

Key Recommendations

Long-term Strategies:

• Implement reforestation with native species to enhance snow retention in the HKH region.
• Develop improved weather forecasting and early warning systems.
• Enhance water infrastructure and enact protective policies for snow-receiving areas.
• Encourage community involvement in decision-making and promote regional cooperation to restore the HKH region.

Climate Change Mitigation:

• Reduce greenhouse gas emissions to combat rising temperatures, with a focus on G-20 countries, which account for 81% of global emissions.
• Transition from fossil fuels to cleaner energy sources.

What is the Hindu Kush Himalaya Region?

• The Hindu Kush Himalayan (HKH) region spans across Afghanistan, Bangladesh, Bhutan, China, India, Kyrgyzstan, Mongolia, Myanmar, Nepal, Pakistan, Tajikistan, and Uzbekistan.

Third Pole:

• This region is often referred to as the "Third Pole" due to its vast reserves of ice and snow.
• It holds significant climatic importance, hosting the largest concentration of ice and snow outside the Arctic and Antarctica.
• Water from the HKH region is crucial for major rivers that flow through 16 countries across Asia.

Key River Systems and their Destinations from HKH:

India's Water Stress and Hydropower

Why in News?

Recently, Moody's Ratings has issued a warning regarding India's worsening water shortages and the impact of climate change-induced natural disasters. These issues threaten various sectors, including agriculture and industry, and could jeopardize the country's sovereign credit rating.

What is the Current State of Hydropower Generation in India?

• Hydropower generation in India has decreased by 17.33%, falling from 162.05 billion units in FY23 to 133.97 billion units in FY24.
• The current installed capacity for large hydropower stands at 46.92 GW, making up about 10% of India's total power generation capacity of 442.85 GW.
• In FY24, the addition of large hydropower capacity has slowed, with only 60 MW added compared to 120 MW in FY23.

Factors Responsible for Low Hydropower Generation:

• Delayed and irregular monsoons: The southwest monsoon has been delayed, and patchy rainfall due to the El Niño effect and a prolonged dry spell last year has diminished water reservoir levels.
• Low reservoir levels: Key reservoirs in India have a live storage of only 37.662 BCM, which is just 21% of their total capacity and 80% lower than the previous year.
• Shutdown of hydropower plants: Some hydropower plants have remained offline due to the adverse effects of floods and cloudbursts.

Implications of Low Hydropower for the Energy Sector:

• Increased reliance on thermal power: As hydropower generation decreases, coal-fired plants will need to compensate for the rising power demand.
• Disruptions in power supply: Industries that rely heavily on water, such as coal power plants and steel manufacturers, will be adversely affected by water shortages.
• Reduced hydropower potential: The decline in water availability will further limit hydropower generation, which is essential for India's renewable energy targets.

What is the Current State of Water in India?

• Water scarcity: With 18% of the world's population but only 4% of its freshwater resources, India faces significant water stress.
• Water pollution: Approximately 50% of India's rivers are contaminated, rendering them unsafe for drinking and irrigation.
• Overdependence on groundwater: India is the largest consumer of groundwater, which is being depleted rapidly.
• Climate vulnerability: About three-quarters of India's districts are at risk from extreme weather events, exacerbating water availability issues.

What are the Causes of Water Stress in India?

• Rapid economic growth and urbanization: Population growth from 361 million in 1951 to over 1.3 billion in 2024 has significantly increased water demand.
• Declining water availability: Average annual water availability per capita is expected to drop to 1,367 cubic meters by 2031.
• Climate change and weakening monsoon patterns: Warming oceans are disrupting monsoon patterns, leading to severe droughts.
• Agricultural practices and inefficient usage: Agriculture consumes over 85% of India's water, with inefficient irrigation methods worsening the strain.
• Groundwater depletion: Overexploitation of groundwater resources has led to a crisis, with 54% deemed overexploited.
• Poor water infrastructure and management: Deficiencies in India's water management systems result in significant waste and inefficiency.
• Water pollution: Industrial, agricultural, and domestic pollution has further contaminated water sources.

What are the Implications of Water Scarcity in India?

• Health impacts: Inadequate access to safe drinking water leads to health issues, with around 200,000 annual deaths attributed to water-related problems.
• Ecological damage: Water scarcity threatens wildlife and natural habitats, causing conflicts and endangerment of species.
• Reduced agricultural productivity: Water scarcity negatively impacts crop yields, threatening food security and increasing poverty among farmers.
• Economic losses: Water scarcity can hinder India's economic growth by affecting industrial production and driving up water treatment costs.
• Effect on India’s climate goal: Reduced hydropower output complicates India's objectives to generate 50% of electricity from non-fossil sources by 2030.

Way Forward

• Sustainable groundwater management: Implementing mechanisms for artificial recharge and rainwater harvesting is essential.
• Smart agriculture: Adoption of drip irrigation can significantly reduce water usage while improving crop yields.
• Blue-green infrastructure: Integrating natural water management solutions can enhance watershed management and ecological sustainability.
• Using modern water management techniques: Technology advancements can improve water purification and management efficiency.

Summer Solstice 2024

Why in news?

Recently, 21 June has been recognized as the day of the summer solstice in the northern hemisphere. This event signifies the onset of summer or midsummer, occurring when one of Earth’s poles is tilted at its maximum towards the sun.

What is the Summer Solstice?

• The concept of the summer solstice dates back to around 200 BC, attributed to the ancient Greek scholar Eratosthenes.
• Eratosthenes conducted an experiment to measure the Earth's circumference by observing that on the summer solstice, sunlight fell directly into a well in Aswan, Egypt, indicating the sun was precisely overhead.
• He calculated the difference in shadow lengths between Aswan and Alexandria, along with the distance separating the two cities, to derive an early and remarkably accurate estimate of the Earth’s circumference.

About:

• The summer solstice marks the longest day of the year, characterized by the sun reaching its apex in the sky.
• During this solstice, the Earth's axis is tilted such that the North Pole is inclined towards the sun while the South Pole is turned away.
• This imaginary axis runs through the Earth from top to bottom, maintaining a consistent tilt of 23.5 degrees relative to the sun.
• In regions near the Arctic Circle (66°33′ North latitude), the sun remains visible throughout the day during the solstice.
• The amount of sunlight received by specific areas in the Northern Hemisphere on the summer solstice varies based on their latitudinal position.

Effect:

• During the solstice, regions in the Northern Hemisphere are positioned closest to the sun, with sunlight shining directly over the Tropic of Cancer (23.5° North).
• The Earth's rotation on its axis results in the Northern Hemisphere receiving increased direct sunlight from March through September.
• The solar energy received at the North Pole on this day is approximately 30% higher than that at the Equator.

Cultural Significance:

• Across various cultures, the summer solstice is a period of considerable importance, often associated with numerous festivals and rituals worldwide.

What is Cold Lava?

Why in news

Mt. Kanlaon Natural Park on Negros Island, Philippines, experienced rivers of cold lava after a recent explosive eruption.

• Known as "lahar" in Indonesian, cold lava occurs when rainwater mixes with volcanic debris such as ash, sand, and pebbles.
• This mixture creates a concrete-like substance that can devastate everything in its path.
• During an eruption, rain can carry cold lava down a volcano's slopes, impacting nearby towns or villages.
• Unlike traditional lava flows, which are slow-moving, cold lava can travel at speeds of hundreds of kilometers per hour, reaching distances of up to 60 km from the volcano.

• A defining feature of cold lava is its capacity to pick up additional debris and sediment as it flows downhill.
• This accumulation can significantly increase its volume and destructive power, transforming it from a relatively harmless flow into a formidable force.
• Cold lava is considered more dangerous and lethal than regular lava flows due to its high density and abrasive characteristics.
• It poses considerable threats to infrastructure, including buildings, bridges, and roads, as well as risks to human life.
• While cold lava appears similar to wet concrete on the surface, it remains hot internally due to chemical processes occurring within the volcanic material.
• Although commonly associated with volcanic eruptions, lahars can also form in the absence of an eruption. Heavy rainfall or melting snow can erode and transport loose volcanic sediment, creating a slurry, particularly when vegetation has not yet recovered from recent eruptions.