Environment and Ecology Archives

261. Ozone layer depletion is a major phenomenon in :

Ozone layer depletion is a major phenomenon in :

[amp_mcq option1=”Troposphere” option2=”Stratosphere” option3=”Thermosphere” option4=”Exosphere” correct=”option2″]

This question was previously asked in

UPSC CAPF – 2015

The ozone layer is a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet (UV) radiation. Ozone (O₃) concentration is highest in the lower portion of the stratosphere, from about 15 to 35 kilometers above Earth’s surface, although it is present in small quantities throughout the atmosphere. Ozone depletion, primarily caused by human-produced ozone-depleting substances like chlorofluorocarbons (CFCs), is a significant phenomenon occurring within the stratosphere.

The Earth’s atmosphere is divided into several layers: Troposphere (lowest), Stratosphere, Mesosphere, Thermosphere, and Exosphere (highest). The ozone layer resides primarily within the stratosphere.

While the stratosphere is where beneficial ozone is found and depleted, ozone is also present in the troposphere. Tropospheric ozone is a key component of smog and is considered a harmful air pollutant and a greenhouse gas, but it does not form a “layer” in the same way as stratospheric ozone and is not where the major depletion phenomenon occurs.

262. Which one among the following substances is NOT a ‘green house’ gas ?

Which one among the following substances is NOT a ‘green house’ gas ?

[amp_mcq option1=”Water vapour” option2=”Chlorofluorocarbon” option3=”Methane” option4=”Nitrogen” correct=”option4″]

This question was previously asked in

UPSC CAPF – 2015

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Nitrogen (N₂) is the most abundant gas in the Earth’s atmosphere, making up about 78%. However, it is not considered a greenhouse gas because its symmetrical diatomic molecule does not absorb and re-emit infrared radiation effectively, unlike gases with three or more atoms (like water vapour, methane) or asymmetrical diatomic molecules (like carbon monoxide) or complex molecules like CFCs.

Greenhouse gases absorb and emit infrared radiation, trapping heat in the atmosphere. Major greenhouse gases include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), water vapour (H₂O), and fluorinated gases (like CFCs, HFCs, PFCs, SF₆).

While nitrogen does not directly contribute to the greenhouse effect, nitrogen oxides (like N₂O, which is a powerful greenhouse gas, and NO₂) are significant air pollutants and can be formed from nitrogen and oxygen under high temperatures. However, the question specifically asks about ‘Nitrogen’ (referring to N₂).

263. It is reported that there is an ongoing decrease in the pH value of oc

It is reported that there is an ongoing decrease in the pH value of ocean water because of global warming. It happens due to :

[amp_mcq option1=”larger uptake of CO₂ by ocean water” option2=”lesser uptake of CO₂ by ocean water” option3=”larger uptake of atmospheric nitrogen by ocean water” option4=”lesser uptake of atmospheric nitrogen by ocean water” correct=”option1″]

This question was previously asked in

UPSC CAPF – 2015

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The correct answer is A. The decrease in ocean pH (ocean acidification) is primarily caused by the ocean absorbing increasing amounts of atmospheric carbon dioxide (CO₂), which is linked to global warming.

Global warming is largely caused by increased atmospheric concentrations of greenhouse gases, particularly CO₂, resulting from human activities. The ocean acts as a significant sink for atmospheric CO₂, absorbing about a quarter of the anthropogenic emissions. When CO₂ dissolves in seawater, it reacts with water to form carbonic acid (H₂CO₃). Carbonic acid then dissociates, releasing hydrogen ions (H⁺), which lowers the pH of the water, making it more acidic. Increased CO₂ in the atmosphere due to factors causing global warming leads to increased CO₂ uptake by the ocean, driving this acidification process.

Ocean acidification has significant impacts on marine ecosystems, particularly on organisms with calcium carbonate shells or skeletons, such as corals, shellfish, and plankton. Lower pH makes it harder for these organisms to build and maintain their structures. Atmospheric nitrogen uptake does occur in the ocean (nitrogen fixation), but it does not directly cause large-scale ocean acidification; it is related to nutrient cycles and marine productivity.

264. The trees of tropical rainforest have buttress roots because :

The trees of tropical rainforest have buttress roots because :

[amp_mcq option1=”they help to provide aeration to soils” option2=”the organisms found in the buttresses have a symbiotic relationship” option3=”the trees belong to gramineae family” option4=”the buttresses have to bear the mechanical load of hardwoods” correct=”option4″]

This question was previously asked in

UPSC CAPF – 2015

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The correct answer is D. Buttress roots provide structural support to large trees in unstable tropical rainforest soils, helping them bear their mechanical load and resist toppling.

Tropical rainforest soils are typically shallow, nutrient-poor, and sometimes waterlogged. Trees in these environments often do not develop deep taproots for stability. Instead, they rely on widespreading, shallow root systems and buttress roots at the base of the trunk. Buttress roots are large, triangular supports that spread horizontally and vertically, increasing the tree’s base area and providing stability against strong winds and the weight of the canopy and epiphytes.

While roots are involved in aeration (A), buttress roots’ primary function is structural support. Symbiotic relationships (B), such as mycorrhizae, occur on the roots for nutrient uptake, but the buttress structure itself is not defined by this. The Gramineae family (C) refers to grasses, not the large hardwood trees typical of tropical rainforests. The mechanical load (D) refers to the considerable weight and size of the trees which the buttresses help to support in the face of challenging soil conditions.

265. Arrange the following fuels in the decreasing order of air pollution c

Arrange the following fuels in the decreasing order of air pollution caused by burning a kilogram of each of them :

[amp_mcq option1=”CNG, Petrol, Diesel” option2=”Diesel, Petrol, CNG” option3=”Petrol, Diesel, CNG” option4=”Diesel, CNG, Petrol” correct=”option2″]

This question was previously asked in

UPSC CAPF – 2014

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The question asks to arrange fuels in decreasing order of air pollution caused by burning a kilogram of each. Generally, different fuels produce varying amounts of pollutants like particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons, and sulfur oxides (SOx).
– Diesel: Diesel fuel is heavier than petrol and its combustion typically produces more particulate matter and higher levels of NOx, especially from older engines or those without modern emission controls. It can also contain more sulfur, leading to SOx emissions.
– Petrol (Gasoline): Petrol combustion produces significant amounts of CO, NOx, and unburnt hydrocarbons. While generally producing less PM than diesel, its emissions of other pollutants can be substantial.
– CNG (Compressed Natural Gas): CNG is primarily methane (CH4). Burning CNG is considered much cleaner than burning petrol or diesel. It produces significantly lower levels of PM, CO, NOx, and hydrocarbons. It contains virtually no sulfur, so no SOx emissions.
Ranking from most polluting to least polluting per kilogram burned (considering typical emissions profiles): Diesel > Petrol > CNG.
Therefore, the decreasing order of air pollution caused is Diesel, Petrol, CNG.

Understand the relative environmental impact and pollution characteristics of common fuels like Diesel, Petrol, and CNG. CNG is generally considered the cleanest of the three in terms of air pollutant emissions.

The specific emissions profile can vary depending on engine technology, fuel quality, and emission control systems (like catalytic converters). However, the general ranking of CNG being cleaner than petrol, which is cleaner than diesel (especially regarding PM) is widely accepted in the context of conventional engines.

266. Pesticide treadmill refers to :

Pesticide treadmill refers to :

[amp_mcq option1=”Increase in concentration of pesticides in the body of the organism” option2=”Increase in doses of pesticides to prevent the resurgence of pests that were being controlled” option3=”Development of resistance in plant due to excessive and prolonged use of pesticide” option4=”Production of more synthetic pesticides” correct=”option2″]

This question was previously asked in

UPSC CAPF – 2014

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Pesticide treadmill refers to the cycle where increasing amounts or more potent pesticides are needed because target pest populations develop resistance to the chemicals being used.

Pesticide resistance occurs through natural selection. When a pesticide is applied, it kills susceptible individuals, but some individuals with resistance genes survive. These survivors reproduce, passing on their resistance. Over time, the population becomes dominated by resistant individuals. This renders the original pesticide ineffective at its previous dose, requiring higher doses or the use of different, often stronger, pesticides to achieve control. This escalating use of pesticides is the “treadmill”.

This phenomenon has significant environmental and economic consequences, including increased costs for pest control, potential harm to non-target organisms, pollution of soil and water, and health risks associated with higher pesticide exposure. Integrated Pest Management (IPM) strategies aim to break this cycle by using a combination of methods (biological, cultural, physical, and chemical) to manage pests sustainably.

267. Methane is a very potent green house gas. It is converted to carbon di

Methane is a very potent green house gas. It is converted to carbon dioxide to ease its overall effect on global warming. This process is known as :

[amp_mcq option1=”Blocking” option2=”Ceiling” option3=”Flaring” option4=”Stooping” correct=”option3″]

This question was previously asked in

UPSC CAPF – 2014

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The correct answer is Flaring.

Methane is a potent greenhouse gas. Methane flaring is a process where methane (typically waste gas like natural gas from oil/gas extraction, landfills, or wastewater treatment) is burned. Burning methane converts it primarily into carbon dioxide (CO2) and water vapor. While CO2 is also a greenhouse gas, methane has a much higher global warming potential (GWP) than CO2 over relevant time scales (e.g., GWP of methane is about 25-28 times that of CO2 over 100 years). Therefore, converting methane to CO2 through flaring reduces the overall warming impact compared to releasing the same amount of methane into the atmosphere.

Flaring is a common practice to dispose of unwanted methane, especially when it’s not economically viable to capture and utilize it. While flaring reduces the GWP compared to venting methane, it still produces CO2, which contributes to global warming. Alternatives include capturing methane for use as fuel or converting it to other chemicals.

268. Which one among the following is successfully tested in Germany recent

Which one among the following is successfully tested in Germany recently as world’s first green helicopter which is environment friendly and emission free ?

[amp_mcq option1=”Volocopter” option2=”Sikorsky” option3=”Eurocopter” option4=”Bell” correct=”option1″]

This question was previously asked in

UPSC CAPF – 2014

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In late 2013, the German company E-volo successfully conducted manned test flights of its prototype electric multirotor aircraft, the Volocopter VC200. This aircraft was widely reported at the time as being the world’s first certified electric multirotor (often referred to in popular media as an electric helicopter, though technically a multirotor VTOL aircraft) and was highlighted for being emission-free and environmentally friendly.

The Volocopter is an electric vertical take-off and landing (eVTOL) aircraft, representing a new class of environmentally friendly rotorcraft as opposed to traditional fuel-powered helicopters.

Sikorsky, Eurocopter (now Airbus Helicopters), and Bell are established manufacturers of traditional helicopters powered by jet engines, although they are also developing hybrid and electric models more recently. The question specifically refers to a successful test of a “first green helicopter” in Germany around Dec 2013, which aligns with the Volocopter’s milestone flight.

269. The Perform, Achieve and Trade (PAT) scheme in India is related to :

The Perform, Achieve and Trade (PAT) scheme in India is related to :

[amp_mcq option1=”Education” option2=”Global warming” option3=”Energy efficiency” option4=”Bharat Nirman” correct=”option3″]

This question was previously asked in

UPSC CAPF – 2014

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The Perform, Achieve and Trade (PAT) scheme is a market-based mechanism aimed at enhancing energy efficiency in large energy-consuming industries in India. It is a key component of the National Mission for Enhanced Energy Efficiency (NMEEE) under India’s National Action Plan on Climate Change (NAPCC).

The PAT scheme targets Designated Consumers (DCs) in specific energy-intensive sectors, setting energy reduction targets for them. Achieving these targets earns them Energy Saving Certificates (ESCs) which can be traded.

The scheme is implemented by the Bureau of Energy Efficiency (BEE) under the Ministry of Power. While contributing indirectly to mitigating global warming by reducing energy consumption, its direct focus and mechanism are centred on improving energy efficiency across various industrial sectors.

270. The logo of which of the following famous organizations is a Giant

The logo of which of the following famous organizations is a Giant Panda?

[amp_mcq option1=”World Wildlife Fund or World Wide Fund for Nature (WWF)” option2=”International Union for Conservation of Nature and Natural Resources (IUCN)” option3=”United Nations Educational, Scientific and Cultural Organization (UNESCO)” option4=”United Nations Environment Programme (UNEP)” correct=”option1″]

This question was previously asked in

UPSC CAPF – 2013

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The correct option is A.

– The question asks for the organization whose logo is a Giant Panda.
– A) **World Wildlife Fund or World Wide Fund for Nature (WWF):** This international non-governmental organization, founded in 1961, is dedicated to wildlife preservation and reducing human impact on the environment. Its famous logo is a stylized depiction of a Giant Panda named Chi Chi, which was transferred from the London Zoo to WWF in 1961.
– B) **International Union for Conservation of Nature and Natural Resources (IUCN):** IUCN’s logo features a globe surrounded by laurel leaves.
– C) **United Nations Educational, Scientific and Cultural Organization (UNESCO):** UNESCO’s logo depicts the profile of the Parthenon temple inside a square frame.
– D) **United Nations Environment Programme (UNEP):** UNEP’s logo features a stylized human figure and laurel leaves within a circle.
– Therefore, the Giant Panda is the logo of the World Wildlife Fund (WWF).

The original panda design for the WWF logo was created by Sir Peter Scott, inspired by the panda Chi Chi. It was adopted because the panda is endangered, easily recognizable, and has appealing features suitable for a logo.