Why is it in the News?

The fourth global mass coral bleaching event has been triggered by extraordinary ocean temperatures, the US National Oceanic and Atmospheric Administration (NOAA) said recently.

What are Corals and Coral Reefs?

• Corals are essentially animals, which are sessile, meaning they permanently attach themselves to the ocean floor.
• They use their tiny tentacle-like hands to catch food from the water and sweep it into their mouth.
• Each individual coral animal is known as a polyp and it lives in groups of hundreds to thousands of genetically identical polyps that form a ‘colony’.
• Corals are largely classified as either hard coral or soft coral.
• It is the hard corals that are the architects of coral reefs — complex three-dimensional structures built up over thousands of years.
• Unlike soft corals, hard corals have stony skeletons made out of limestone that are produced by coral polyps.
• When polyps die, their skeletons are left behind and used as foundations for new polyps.
• Coral reefs, also referred to as “rainforests of the sea”, have existed on the Earth for nearly 450 million years.
  • Australia’s Great Barrier Reef is the largest in the world, stretching across 2,028 kilometers.

What is the Significance of Corals?

• Coral reefs have a crucial role in marine ecosystems.
• Thousands of marine species can be found living on one reef.
  • For instance, “the Great Barrier Reef contains over 400 coral species, 1,500 fish species, 4,000 mollusc species and six of the world’s seven sea turtle species”.
• Research has shown that there could be millions of undiscovered species of organisms living in and around reefs.
• These massive structures also provide economic goods and services worth about $375 billion each year.
• More than 500 million people across the world depend on coral reefs for food, income, and coastal protection from storms and floods.
• Coral reefs can absorb up to 97% of the energy from waves, storms, and floods, which prevents loss of life, property damage, and soil erosion.
• Therefore, the absence of coral reefs would not only result in severe ramifications for marine life but also for humans.

What is Coral Bleaching?

• Most corals contain algae called zooxanthellae ( plant-like organisms) in their tissues.
• Corals and zooxanthellae have a symbiotic relationship.
• While corals provide zooxanthellae a safe place to live, zooxanthellae provide oxygen and organic products of photosynthesis that help corals to grow and thrive.
• Zooxanthellae also give bright and unique colors to corals.
• Corals are very sensitive to light and temperature and even a small change in their living conditions can stress them.
• When stressed, they expel zooxanthellae and turn entirely white.
  • This is called coral bleaching.
• Coral bleaching doesn’t immediately lead to the death of corals.
• They rather go under more stress and are subject to mortality.
• Coral bleaching reduces the reproductivity of corals and makes them more vulnerable to fatal diseases.
• If the bleaching is not too severe, corals have been known to recover.
• Global mass bleaching of coral reefs is when significant coral bleaching is confirmed in the Atlantic, Indian, and Pacific oceans.
• Such events are a relatively new phenomenon.
• The first one took place in 1998 in which 20% of the world’s reef areas suffered bleaching-level heat stress.
• The next two global bleaching events occurred in 2010 (35% of reefs affected) and between 2014 and 2017 (56% of reefs affected).

What can be the impact of the event?

• As the global mass bleaching event is still unfolding, its full impact will not be known for a while.
• With global temperatures soaring, such events are expected to become more frequent and longer.
• As a result, the world may lose the vast majority of its coral reefs at 1.5 degrees Celsius of warming, and virtually all at 2 degrees.
• Currently, the average global temperature of the Earth has increased by at least 1.1 degree Celsius since 1850.
• To curb global warming to no more than 1.5 degrees Celsius, countries need to bring GHG emissions to a net zero by 2050, according to the Paris Agreement.
  The goal, however, is unlikely to be achieved as record levels of GHG emissions have continued to be emitted into the atmosphere.

Why is it in the News?

A remote volcano in Indonesia’s outermost region erupted again on April 19 after the crater threw up columns of smoke and lava multiple times this week and forced thousands to evacuate.

About Mount Ruang:

• Mount Ruang is an active stratovolcano located in the Sangihe Islands arc, North Sulawesi, Indonesia.
• It is the southernmost volcano in the region, situated on an island that measures 4 by 5 kilometers wide.
• The summit features a partial lava dome and reaches an altitude of 725 meters.
• Mount Ruang has experienced multiple eruptions throughout its history, with the most recent ongoing eruption starting on April 18, 2024.
• The volcano's eruptions often generate ash columns, lava flows, and gas emissions, posing risks to nearby communities.

What is a Stratovolcano?

• A stratovolcano is a tall volcano shaped like a cone, formed by various layers of materials such as volcanic ash, hardened lava, pumice, and tephra.
• Stratovolcanoes are steep and have periodic explosive and effusive eruptions, although some have calderas, which are collapsed craters.
• The highly viscous lava that flows from this type of volcano cools and hardens and in turn, does not spread far.
• The magma that forms this lava is generally felsic.
• Stratovolcanoes are more common than shield volcanoes.
  • One of the famous stratovolcanoes is Vesuvius which destroyed Herculaneum and Pompeii in 79 CE.

Formation Of Stratovolcanoes:

• Stratovolcanoes occur mostly in subduction zones, where the oceanic crust slides under continental crust.
• The descent of the oceanic plate causes the release of trapped water from hydrated minerals and porous rock, into the mantle rock in the area above the oceanic slab.
• This process occurs at different pressures depending on the minerals.
• The water lowers the mantle rock’s melting point, causing partial melting and its rise to the lithosphere forming a temporary pool.
• The magma then continues to rise through the crust collecting rock rich in silica.
• The magma finally pools in the magma chamber which is either within or under the volcano.
• The low pressure at this point causes the volatile compounds such as water, carbon dioxide, and sulfur dioxide dissolved in the magma to escape.
• When the magma and gas accumulate to a critical level, they overcome the rock blockage of the volcanic cone and erupt violently.

Why is it in the News?

The Global Alliance for Incinerator Alternatives (GAIA) Asia Pacific, in collaboration with other environmental organizations, has called on the Association of Southeast Asian Nations (ASEAN) to take decisive action in response to plastic pollution.

About Global Alliance for Incinerator Alternatives (GAIA):

• The Global Alliance for Incinerator Alternatives (GAIA) is an alliance of over 1,000 grassroots groups, NGOs, and individuals working towards a transition from a linear, extractive economy to a circular system.
• GAIA's primary objective is to create a world that prioritizes people's right to a safe and healthy environment, free from toxic pollution and resource depletion.
• GAIA envisions a just, zero-waste world where communities' rights are respected, and ecological limits are acknowledged. To achieve this vision, the alliance focuses on:
• Eliminating Incineration: GAIA advocates for alternatives to incineration and promotes waste management practices that protect the environment and public health.
• Promoting Zero Waste: The alliance supports the adoption of zero-waste strategies, emphasizing waste reduction, reuse, and recycling to conserve resources and reduce pollution.
• Addressing Plastic Pollution: GAIA recognizes the global plastic pollution crisis and works on initiatives to reduce plastic waste and promote sustainable alternatives.
• Mitigating Climate Change: GAIA advocates for climate-friendly waste management practices, emphasizing the importance of reducing greenhouse gas emissions from waste disposal.

What is Incineration?

• Incineration is a waste treatment process that involves burning hazardous materials at high temperatures to destroy contaminants.
  • This process takes place in an "incinerator," a furnace specifically designed to safely burn hazardous materials within a combustion chamber.
• Various types of hazardous materials can be treated through incineration, including soil, sludge, liquids, and gases.
  • While incineration effectively destroys many harmful chemicals such as solvents, polychlorinated biphenyls (PCBs), and pesticides, it does not destroy metals like lead and chromium.
• Modern incinerators are equipped with air pollution control mechanisms, such as fabric filters, scrubbers, and electrostatic precipitators.
  • These technologies help remove fly ash and gaseous contaminants generated during the incineration process, mitigating its environmental impact.
  • Despite its benefits in waste treatment, incineration remains a topic of debate due to concerns about residual pollutants and the potential for contributing to greenhouse gas emissions.

Why is it in the News?

In new peer-reviewed research, physicists from Princeton University have confirmed that electrons don’t even need atoms to party together.

What are Wigner Crystals?

• Wigner Crystals are composed entirely of electrons, unlike the common crystals which are formed by atoms or molecules.  
• These negatively charged particles, which are known for their role in electricity and chemical bonding, can, under specific circumstances, arrange themselves into a lattice structure, creating a crystal made purely of electrons.
• The conditions required for the formation of Wigner Crystals are quite stringent.
  • They occur at very low electron densities, where the repulsive Coulomb forces between the electrons dominate over their kinetic energy.
  • This means that the electrons must be spread out enough so that their mutual repulsion causes them to settle into a fixed pattern, minimizing their potential energy.
• The discovery was made possible by cooling a two-dimensional electron system to near absolute zero and reducing the electron density to a critical level.
  • Under these conditions, the electrons crystallized into a lattice, much like the atoms in a solid.
  • The visualization of this electron lattice marks a monumental step in our understanding of the quantum phases of matter.
• The implications of this discovery are profound.
  • Wigner Crystals could provide insights into the behavior of electrons in low-density environments, such as those found in semiconductors and other electronic materials.
  • This could lead to the development of new technologies and materials with unique electronic properties.
• Moreover, the study of Wigner Crystals could shed light on other exotic states of matter and the fundamental principles of quantum mechanics.
• The confirmation of Wigner Crystals underscores the importance of theoretical physics and how ideas that once seemed purely speculative can lead to tangible discoveries.
• The realization of Wigner Crystals opens up a new chapter in the study of condensed matter physics.
  •  It stands as a bridge between the abstract world of quantum mechanics and the tangible reality of material science.
  • As we continue to explore the quantum landscape, Wigner Crystals will undoubtedly play a pivotal role in unraveling the mysteries of the electron and the intricate dance of particles that constitute the fabric of our universe.

Why is it in the News?

Nestlé’s products for babies in Asia, Africa, and Latin America were found to contain added sugars, while the same products sold in Europe did not have it, according to a recent report.

Highlights of the Report on Nestle:

• A report by the Swiss organization Public Eye titled 'How Nestlé gets children hooked on sugar in lower-income countries' scrutinized Nestlé for employing varying nutritional standards across its products depending on the country, with unclear sugar content labeling.
• The report highlighted Nestlé's Cerelac, the world's largest baby cereal brand, which contains significantly higher sugar levels in markets like India, Ethiopia, and Thailand compared to Germany and the UK.
• Despite sugar not being recommended for infants, Nestlé's baby food products with added sugars are allowed under some countries' national legislation, conflicting with WHO guidelines.
  • WHO recommends reducing daily free sugar intake to less than 10% of total energy intake, preferably less than 5% (around 25 grams per person per day), for better health.
• Nestlé India claims to have reduced added sugars by up to 30% in their infant cereals portfolio over the last five years, depending on the variant.

What are Added Sugars?

• Sugar is a simple carbohydrate.
• Some food items have sugar that is naturally occurring.
  • It is “found in milk (lactose) and fruit (fructose) or any product that contains milk (such as yogurt, milk, or cream) or fruit (fresh, dried) contains some natural sugars.
• Free sugar or added sugar is added separately to a food item during preparation or processing.
• It can “include natural sugars such as white sugar, brown sugar, and honey, as well as other caloric sweeteners that are chemically manufactured (such as high fructose corn syrup).

Why is Added Sugar Bad?

• Excessive consumption of added sugars poses several health risks.
• Limiting sugar intake is essential for maintaining a healthy diet and preventing various diseases.

The following are some reasons why added sugars can be harmful:

• Poor Nutritional Balance: Consuming too much-added sugar can lead to increased overall energy intake, often replacing nutritionally adequate calories from healthier food sources.
  • This results in an unbalanced diet lacking essential nutrients, increasing the risk of malnutrition and other health problems.
• Increased Risk of Non-Communicable Diseases: Excessive sugar consumption is associated with a higher risk of developing non-communicable diseases such as diabetes, obesity, and cardiovascular ailments.
  • These diseases can have severe long-term consequences on overall health and well-being.
• Unnecessary for Infants and Children: Adding sugar to foods offered to babies and young children is unnecessary and can be highly addictive, establishing unhealthy eating habits that continue into adulthood.
  • Early exposure to sugar is also associated with tooth decay and can contribute to nutrition-based disorders later in life.