Greenhouse Effect and Climate Change

51. The laboratory from where carbon dioxide measurements have been taken

The laboratory from where carbon dioxide measurements have been taken since 1958 A.D., which form the basis of present global warming data base is :

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Maragheh observatory
Mauna Loa observatory
Griffith observatory
Sydney observatory
This question was previously asked in
UPSC CAPF – 2009
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The Mauna Loa Observatory in Hawaii is the site where continuous measurements of atmospheric carbon dioxide concentration began in 1958, forming the basis of the Keeling Curve and a key dataset for understanding global warming.
The Keeling Curve, named after Charles David Keeling, shows the steady increase in atmospheric CO2 concentration since the late 1950s, along with seasonal fluctuations. This is one of the most important pieces of evidence for anthropogenic climate change.
The Mauna Loa Observatory is operated by the National Oceanic and Atmospheric Administration (NOAA). Its remote location on a volcanic mountain top minimizes local pollution influences, making it an ideal site for monitoring global atmospheric composition.

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52. Which one of the following greenhouse gases is in largest concentratio

Which one of the following greenhouse gases is in largest concentration in the atmosphere?

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Chlorofluorocarbon
Nitrous oxide
Carbon dioxide
Methane
This question was previously asked in
UPSC NDA-2 – 2018
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Among the given options, Carbon dioxide is in the largest concentration in the atmosphere.
– Greenhouse gases trap heat in the Earth’s atmosphere, contributing to the greenhouse effect.
– Common greenhouse gases include water vapor (H₂O), carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), ozone (O₃), and chlorofluorocarbons (CFCs).
– While water vapor is the most abundant greenhouse gas overall, its concentration is highly variable and often considered separately when discussing anthropogenic emissions.
– Among the options listed (excluding water vapor), carbon dioxide (CO₂) has by far the highest concentration in the Earth’s atmosphere. Its concentration is currently over 400 parts per million (ppm).
– Methane (CH₄) concentration is around 1.9 ppm, Nitrous oxide (N₂O) is around 0.34 ppm, and Chlorofluorocarbons (CFCs) are present in much lower concentrations (parts per billion or trillion).
– The radiative efficiency (global warming potential) and atmospheric lifetime vary significantly among greenhouse gases. CO₂ has a relatively low radiative efficiency compared to CH₄ or N₂O, but its high concentration and long atmospheric lifetime make it the largest contributor to anthropogenic climate change.
– The concentrations of these gases are monitored globally by various scientific bodies.

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53. Which one of the following is not a Green House Gas?

Which one of the following is not a Green House Gas?

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Water vapours
Methane
Ozone
Carbon Monoxide
This question was previously asked in
UPSC NDA-2 – 2015
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Carbon Monoxide (CO) is not considered a primary greenhouse gas, unlike water vapour, methane, and ozone.
Greenhouse gases are atmospheric gases that absorb and emit infrared radiation, trapping heat in the atmosphere and contributing to the greenhouse effect. Common greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), water vapour (H2O), and ozone (O3). Carbon monoxide is a significant air pollutant and can have indirect effects on the climate by influencing the concentrations of some greenhouse gases, but it does not directly absorb infrared radiation in the same way as primary GHGs.
While CO is not a primary GHG, it plays a role in atmospheric chemistry, affecting the formation and destruction of other gases like methane and ozone, which are GHGs. However, in lists of direct GHGs, CO is typically excluded.

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54. The UN COP-27 Summit relates to :

The UN COP-27 Summit relates to :

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Russia-Ukraine war
Terrorism and counter-terrorism
Climate change
Interpol
This question was previously asked in
UPSC NDA-1 – 2023
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The UN COP-27 Summit refers to the 27th session of the Conference of the Parties (COP) to the UNFCCC (United Nations Framework Convention on Climate Change). These annual conferences are the highest decision-making body of the UNFCCC and are focused on addressing climate change.
– COP stands for Conference of the Parties.
– The UNFCCC is the international treaty on climate change.
– COPs are the main forum for negotiating and implementing international climate agreements.
– COP-27 was held in Sharm El Sheikh, Egypt, in November 2022, specifically addressing climate change issues.
Previous COPs include COP21 in Paris (which resulted in the Paris Agreement) and COP26 in Glasgow. The COP summits cover various aspects of climate action, including mitigation, adaptation, finance, and loss and damage.

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55. Which one of the following is not a main greenhouse gas ?

Which one of the following is not a main greenhouse gas ?

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Water vapour
Oxygen
Carbon dioxide
Methane
This question was previously asked in
UPSC NDA-1 – 2023
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Oxygen (O₂) is not considered a main greenhouse gas. Greenhouse gases are atmospheric gases that absorb and emit infrared radiation, trapping heat in the atmosphere.
Main greenhouse gases include water vapour (H₂O), carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and ozone (O₃). Oxygen and Nitrogen, which make up the bulk of the atmosphere, do not absorb infrared radiation effectively and are not greenhouse gases.
Water vapour is the most abundant greenhouse gas in the atmosphere and contributes significantly to the natural greenhouse effect. Carbon dioxide and methane are major contributors to anthropogenic (human-caused) climate change due to their increased concentrations from activities like burning fossil fuels and agriculture.

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56. Which one among the following statements with regard to a climate deal

Which one among the following statements with regard to a climate deal adopted between USA and China in November 2014 is not correct ?

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China committed to cap its output of carbon pollution by the year 2030 or earlier
China committed to increase its use of zero emission energy to 20% by the year 2030
USA agreed to reduce its emissions by 26% - 28% below its year 2005 levels in the year 2025
Both the countries agreed to completely phase out coal technologies by the year 2020
This question was previously asked in
UPSC NDA-1 – 2015
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The US-China Joint Announcement on Climate Change made in November 2014 included commitments from both countries regarding future emissions reductions and clean energy development.
– The US committed to reducing its greenhouse gas emissions by 26%-28% below its 2005 levels by 2025. (Option C is correct)
– China committed to peaking its CO2 emissions around 2030 and increasing the share of non-fossil fuels in its primary energy consumption to around 20% by 2030. (Option A and B are correct, reflecting aspects of China’s commitment).
– There was no agreement in this announcement for either country to completely phase out coal technologies by the year 2020. Both countries continued to rely heavily on coal power in 2014 and planned transitions, not rapid phase-outs by 2020. Therefore, statement D is not correct.
The 2014 US-China climate deal set specific emissions reduction targets and clean energy goals for both countries, but did not include a complete phase-out of coal technologies by 2020.
This joint announcement was a significant step towards the eventual Paris Agreement reached in 2015, demonstrating collaboration between the world’s two largest emitters. However, transitioning away from coal remains a complex and ongoing process for both nations.

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57. When heat rays are reflected from Earth, gases like Carbon dioxide, Ni

When heat rays are reflected from Earth, gases like Carbon dioxide, Nitrous oxide do not allow them to escape back to the space causing our planet to heat up. These gases are known as

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Noble gas
Green-house gas
Hot gas
Blue gas
This question was previously asked in
UPSC NDA-1 – 2015
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The question describes the phenomenon of the greenhouse effect, where certain gases in the atmosphere trap outgoing infrared radiation (heat rays) reflected from the Earth’s surface, causing the planet to warm up. Gases like carbon dioxide, nitrous oxide, methane, and water vapour are known for this property. These gases are specifically called greenhouse gases. Therefore, option B is the correct answer.
Greenhouse gases trap outgoing infrared radiation, causing the greenhouse effect and warming the planet.
Noble gases (like Helium, Neon, Argon) are inert and do not significantly interact with radiation in this way. “Hot gas” and “Blue gas” are not scientific terms used to describe these atmospheric gases and their effect on temperature. The greenhouse effect is a natural process essential for keeping the Earth warm enough to support life, but increased concentrations of these gases due to human activities are causing enhanced global warming.

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58. Which one of the following resolutions in the final agreement reached

Which one of the following resolutions in the final agreement reached at COP28 is associated with the target of achieving ‘Net Zero by 2050’ ?

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Fossil fuel phase-out
Methane emission cuts
Global goal on adaptation
Climate resilience
This question was previously asked in
UPSC CDS-2 – 2024
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In the final agreement reached at COP28 (UAE Consensus), the resolution most directly associated with the target of achieving ‘Net Zero by 2050’ is the call to transition away from fossil fuels. While the text adopted was “transitioning away from fossil fuels” rather than the stronger “phase-out,” this decision is fundamentally aimed at enabling the world to reach net-zero emissions, primarily by drastically reducing the use of coal, oil, and gas. Among the given options, “Fossil fuel phase-out” (or transition) is the action directly addressing the primary source of greenhouse gas emissions driving climate change, and thus is intrinsically linked to achieving Net Zero.
– Achieving ‘Net Zero by 2050’ requires a significant reduction in greenhouse gas emissions, primarily from the burning of fossil fuels.
– The COP28 agreement explicitly linked the call to transition away from fossil fuels to the goal of achieving net zero by 2050.
– Options B, C, and D (Methane cuts, adaptation, resilience) are important aspects of climate action but the fossil fuel resolution is the most direct and comprehensive measure towards the *mitigation* required for Net Zero.
The COP28 agreement represented the first time a COP decision explicitly called for transitioning away from all fossil fuels. Other key elements of the agreement included tripling renewable energy capacity and doubling the rate of energy efficiency improvements by 2030.

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59. Directions : The following five (5) items consist of two statements, S

Directions :
The following five (5) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the correct answer using the code given below.

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Statement I :
34. Global warming signifies the rise in global surface temperature.
Statement II :
The increase of concentration of greenhouse gases in the atmosphere causes the rise in global surface temperature.

Both the statements are individually true and Statement II is the correct explanation of Statement I
Both the statements are individually true but Statement II is not the correct explanation of Statement I
Statement I is true but Statement II is false
Statement I is false but Statement II is true
This question was previously asked in
UPSC CDS-2 – 2017
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Both the statements are individually true and Statement II is the correct explanation of Statement I.
– Statement I: Global warming refers to the long-term increase in the average temperature of the Earth’s climate system, primarily observed as a rise in global surface temperature since the pre-industrial period.
– Statement II: Greenhouse gases (like carbon dioxide, methane, nitrous oxide, etc.) trap heat (infrared radiation) in the Earth’s atmosphere, creating a warming effect. An increase in the concentration of these gases enhances this trapping, leading to a rise in global surface temperature. This increase is primarily attributed to human activities.
Statement II provides the fundamental mechanism behind the phenomenon described in Statement I. The enhanced greenhouse effect caused by increased greenhouse gas concentrations is the principal driver of current global warming.

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60. According to the Climate Change Performance Index (CCPI), 2023, India

According to the Climate Change Performance Index (CCPI), 2023, India climbed two spots to rank

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seventh
eighth
ninth
tenth
This question was previously asked in
UPSC Geoscientist – 2023
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According to the Climate Change Performance Index (CCPI), 2023, India climbed two spots to rank eighth.
– India ranked 8th in the CCPI 2023 report, published by Germanwatch, NewClimate Institute, and Climate Action Network.
– This represents an improvement of two ranks compared to India’s position (10th) in the CCPI 2022.
The CCPI evaluates countries’ climate protection performance across four categories: GHG Emissions, Renewable Energy, Energy Use, and Climate Policy. In the CCPI 2023, no country was ranked in the top three positions, signifying that no country’s performance was deemed sufficient to prevent dangerous climate change. Denmark, Sweden, Chile, and Morocco were ranked 4th, 5th, 6th, and 7th, respectively.

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