• A study published in January 2025, based on field measurements, airmass trajectories, and particle dispersion simulations, concluded that there is no direct relationship between stubble-burning events in Punjab and Haryana and fine particulate matter (PM2.5) levels in Delhi-NCR.
• The research also highlights that crop residue burning in these states contributes only about 14% of PM2.5, making it a minor factor in the particulate matter concentration in the Delhi-NCR region.
• Despite a more than 50% reduction in stubble-burning events from 2015 to 2023, PM2.5 levels in Delhi-NCR remained stable, suggesting other factors at play. The findings were published in the journal Climate and Atmospheric Science.
• Since 2015, high-quality PM2.5 measurements have been conducted at the U.S. Embassy in New Delhi. While stubble-burning events in Punjab and Haryana decreased by 31% and 37% respectively in 2023 compared to the previous year, there was still a 20% rise in PM2.5 levels at the embassy.
• This further underscores the lack of a linear connection between stubble-burning and PM2.5 levels in Delhi-NCR. In August 2022, a network of 30 sensors was deployed across rural and urban areas of Punjab, Haryana, and Delhi.
• Data from these sensors aligned closely with those from the U.S. Embassy’s instrument. While stubble burning nearly ceases after November, the air quality index in Delhi-NCR has consistently been in the "very poor" to "severe" category from December to February since 2016, indicating that factors beyond stubble burning are significant contributors to air pollution.
• The authors note that the volume of biomass burned in Punjab and Haryana does not always correlate with the air quality in urbanized areas like Delhi-NCR, especially during peak rice-stubble burning months (October-November). 
• While there is some correlation between stubble burning and PM2.5 levels in Delhi-NCR when wind conditions are favorable, wind patterns alone do not explain PM2.5 levels.
• Other meteorological factors and local emissions play a significant role, as noted by Dr. Poonam Mangaraj from RIHN, Kyoto, Japan, the paper's first author. She explains that when dispersion conditions are unfavorable—such as low wind speeds or temperature inversions—pollutants may not disperse effectively, weakening or eliminating the correlation.
• Data from sensors recording PM2.5 and carbon monoxide (CO) show a persistent accumulation of fine particulate matter and CO in Delhi at night, suggesting local emissions as a significant factor.
• If stubble burning were the primary cause of air pollution in Delhi-NCR, CO levels would not increase at night. The study observed that day-night differences in PM2.5 levels in Delhi-NCR were about 20%, while CO concentration was about 67% higher at night in 2023 compared to the daytime, and 48% higher in 2022.
• In contrast, day-night variations were more distinct in Punjab and Haryana during intense stubble-burning periods.
• Therefore, the higher CO levels at night in Delhi-NCR suggest that sources other than stubble burning contribute significantly to air pollution

1.In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index? ( UPSC 2016)

1. Carbon dioxide
2. Carbon monoxide
3. Nitrogen dioxide
4. Sulfur dioxide
5. Methane

Select the correct answer using the code given below:

(a) 1, 2 and 3 only   

(b) 2, 3 and 4 only     

(c) 1, 4 and 5 only         

(d) 1, 2, 3, 4 and 5

15 feared dead in stampede at Delhi rly station amid Maha Kumbh rush

For Preliminary Examination: Current events of national importance

For Mains Examination: General Studies-II, III: Government policies and interventions, Disaster Management.

Context:

At least 18 people were killed and several others injured in a stampede at the New Delhi Railway Station late Saturday evening. From the initial 15 persons feared to be dead, the toll rose to 18 as of Sunday morning

Read about:

What is a stampede?

What are the factors leading to stampedes?

Key takeaways:

A stampede refers to a situation in which a large group of people suddenly rush or flee in a chaotic and uncontrolled manner, often causing people to fall, get trampled, or suffer injury. It usually occurs in situations where there is panic, overcrowding, or a sudden rush toward something, such as a door, event, or exit. Stampedes are common in crowded places like concerts, festivals, sports events, or public gatherings, and they can result in significant harm to individuals caught in the crowd

What are the factors leading to stampedes?

Several factors can contribute to stampedes, often involving a combination of physical, psychological, and environmental elements. These factors include:

• Overcrowding:
  One of the primary causes of stampedes is overcrowding, where the number of people exceeds the space available, leading to limited movement and a heightened risk of panic and chaos.

• Panic or Sudden Fear:
  A sudden, loud noise, an unexpected event, or a perceived threat (e.g., fire, explosion, or natural disaster) can cause panic, prompting people to rush toward exits or escape routes without considering the risks.

• Lack of Proper Crowd Control:
  Inadequate crowd management strategies, such as poorly planned entry and exit points, lack of barriers, or insufficient security personnel, can increase the likelihood of stampedes. Proper crowd control measures are crucial to maintaining order.

• Narrow or Blocked Exits:
  If exit routes or pathways are too narrow or blocked, it can prevent people from escaping quickly, leading to a bottleneck effect. This increases pressure on the crowd, often causing individuals to push and shove, leading to a stampede.

• Uneven or Poor Infrastructure:
  Poorly designed or maintained infrastructure, such as unsafe stadiums, event venues, or transport stations, can contribute to dangerous situations. Slippery surfaces, inadequate lighting, and unstable structures can also create hazardous conditions.

• Excitement or Overzealous Behavior:
  In some cases, people may be overly excited about an event (such as a sports match, concert, or religious gathering), which can cause them to behave recklessly and push others, leading to a chain reaction.

• Miscommunication or Rumors:
  False information or rumors, such as someone shouting that there is a fire or a security threat, can escalate panic and lead to hasty decisions and uncoordinated movement among the crowd.

• Delayed or Inefficient Emergency Response:
  If authorities or event organizers fail to respond quickly or efficiently to emerging risks or emergencies, this can exacerbate the situation, making it harder for people to remain calm and orderly.

• Weather Conditions:
  Adverse weather, such as heavy rain or intense heat, can increase the pressure on crowds, pushing them to move more quickly and creating more anxiety, which can lead to a stampede.

• Lack of Crowd Awareness:
  In some cases, people may not be fully aware of the crowd dynamics or the risks of pushing or shoving, leading to unintended escalation

Follow Up Question

1.Discuss the recent measures initiated in disaster management by the Government of India departing from the earlier reactive approach. (UPSC CSE 2020)

 Ten days after the United States deported 104 illegal Indian immigrants in a military plane, 119 more illegal immigrants

For Preliminary Examination:  Current events of national and international importance

For Mains Examination: General Studies-I, II: Effects of globalization on Indian society

Context:

Ten days after the United States deported 104 illegal Indian immigrants in a military plane, 119 more illegal immigrants – the second batch under the current US administration – landed in Amritsar at close to midnight on Saturday. Sources said a third batch of another 157 deportees is expected to land in Amritsar on Sunday night.

Read about:

Who are migrants?

Who are illegal immigrants?

Key takeaways:

Migrants are individuals who move from one place to another, typically across political boundaries (such as from one country to another) or within the same country, often in search of better opportunities, safety, or improved living conditions. Migration can occur for a variety of reasons, and migrants can be classified based on the nature of their movement:

• Internal Migrants:
  These are individuals who move within the borders of their own country, such as from rural areas to urban centers, often in search of employment, education, or improved living standards.

• International Migrants:
  These individuals move across national borders, typically from one country to another. They may do so for work, education, safety, or family reunification.

• Economic Migrants:
  These migrants move in search of better economic opportunities, such as higher wages, improved working conditions, or access to better employment opportunities.

• Refugees and Asylum Seekers:
  Refugees are individuals who flee their home country due to fear of persecution, conflict, violence, or human rights violations. Asylum seekers are individuals who seek international protection in another country due to these same reasons.

• Forced Migrants:
  These migrants are compelled to leave their home country or region due to external factors like war, natural disasters, or persecution. This category includes refugees, internally displaced persons (IDPs), and those displaced by environmental changes.

• Voluntary Migrants:
  Voluntary migration refers to individuals who choose to move to a new location for reasons such as seeking better opportunities, quality of life, or family reunification.

• Seasonal Migrants:
  These are individuals who move temporarily for work or other reasons, such as migrant laborers who work in agriculture or construction during specific seasons and return to their home region afterward.

• Return Migrants:
  Return migrants are individuals who return to their home country after living abroad, often after completing work assignments, studies, or as part of repatriation efforts

Who are illegal immigrants?

Illegal immigrants (also known as undocumented immigrants or unauthorized immigrants) are individuals who enter or reside in a country without the necessary legal permission or documentation required by the immigration laws of that country. Their status as "illegal" typically arises from one of the following circumstances:

• Entering Without Authorization:
  Illegal immigrants may enter a country without going through proper immigration procedures, such as entering without a visa, overstaying a visa, or crossing borders without inspection or permission.

• Overstaying Visa:
  Some individuals may enter a country legally (e.g., on a tourist or student visa) but remain beyond the allowed duration of stay without obtaining the necessary extensions or changes in status.

• Violated Visa Conditions:
  An individual may enter a country with the proper documentation, but if they fail to comply with the conditions of their visa (e.g., working when their visa does not permit employment), they can become illegal immigrants.

• Unlawful Entry or Stay:
  This may include entering through unauthorized routes, such as crossing borders without inspection, or using fraudulent documents like fake passports or visas.

• Expired or Invalid Immigration Status:
  Individuals whose legal immigration status expires or becomes invalid and who fail to renew or change their status can be considered illegal immigrants.

Follow Up Question

US President Donald Trump unveiled his plan to hit the whole world with “reciprocal tariffs”

For Preliminary Examination:  Current events of national and international importance

For Mains Examination: GS III - Economy

Context:

US President Donald Trump unveiled his plan to hit the whole world with “reciprocal tariffs”. The actual imposition will likely happen after April 1st; between now and then, the US trade department is supposed to work out the details for each country

Read about:

What is the Bilateral Trade Agreement between India and the USA?

What is Free Trade Agreement?

Key takeaways:

• Tariffs are taxes levied by an importing country on foreign goods. For example, if an American consumer orders a Banarasi saree from India, US import tariffs would increase the price of the saree, which would ultimately be paid by the consumer. Essentially, tariffs hinder global trade by making it more expensive for everyone involved.

• Trump’s reciprocal tariffs eliminate any exemptions for specific countries, at least in theory. During a press conference in the Oval Office, Trump remarked that “It is a beautiful system. And we don’t have to worry about who is charging too much or too little.”

• In simple terms, Trump announced that the US would impose tariffs on imports equal to the tariffs that other countries charge on US exports, believing this approach to be fair.

• On one hand, it’s true that the US faces a trade deficit with India, meaning more money is leaving the US than coming in, indicating the US’s reliance on India. However, in a global trade environment where countries engage in open and equitable exchanges, the trade deficit is merely a matter of accounting.

• Additionally, it’s possible that in the future, US products will become more affordable for Indians, which could help reduce the trade deficit India has with the US. However, this might lead to a further depreciation of the Indian rupee against the US dollar as more dollars will be needed to purchase US good

A reciprocal tariff is a tariff policy where one country imposes tariffs on imports from another country at the same rate or level as that country imposes on its own exports. In other words, it is a form of retaliation or equivalence where the tariffs imposed by one country are designed to match the tariffs that its trading partner applies to its own goods.

This system is often used in trade negotiations to ensure that tariffs are balanced and that neither country benefits disproportionately from the other's lower tariffs. The idea behind reciprocal tariffs is to create a fair trading environment by ensuring that each country is subject to similar tariff rates, making the trading relationship more equitable.

For example:

• If Country A imposes a 10% tariff on goods from Country B, Country B may respond by imposing a 10% tariff on goods coming from Country A. This ensures that both countries face equal tariffs on each other's goods, which is intended to promote fairness in trade.