Q.1 Which greenhouse gas is primarily responsible for global warming?
Oxygen
Carbon Dioxide
Nitrogen
Hydrogen
Explanation - Carbon dioxide (CO2) is the main greenhouse gas emitted by human activities, contributing significantly to global warming.
Correct answer is: Carbon Dioxide
Q.2 What is the main cause of ozone layer depletion?
CFCs
Methane
Carbon Monoxide
Sulfur Dioxide
Explanation - Chlorofluorocarbons (CFCs) break down ozone molecules in the stratosphere, causing depletion of the ozone layer.
Correct answer is: CFCs
Q.3 Which environmental issue is directly linked to rising sea levels?
Deforestation
Global Warming
Acid Rain
Soil Erosion
Explanation - Global warming causes polar ice to melt and ocean temperatures to rise, leading to rising sea levels.
Correct answer is: Global Warming
Q.4 The Kyoto Protocol is associated with:
Water conservation
Reducing greenhouse gas emissions
Forest management
Wildlife protection
Explanation - The Kyoto Protocol is an international treaty aimed at reducing greenhouse gas emissions to combat climate change.
Correct answer is: Reducing greenhouse gas emissions
Q.5 Which process leads to desertification?
Overgrazing
Urbanization
Reforestation
Irrigation
Explanation - Overgrazing removes vegetation cover, which reduces soil fertility and can lead to desertification.
Correct answer is: Overgrazing
Q.6 Acid rain is mainly caused by emissions of:
CO2 and O2
SO2 and NOx
Methane and CO
Ozone and H2O
Explanation - Sulfur dioxide (SO2) and nitrogen oxides (NOx) from burning fossil fuels combine with water in the atmosphere to form acid rain.
Correct answer is: SO2 and NOx
Q.7 Which country is the largest emitter of CO2 as of 2025?
USA
India
China
Russia
Explanation - China is currently the largest emitter of carbon dioxide due to its industrial activities and energy consumption.
Correct answer is: China
Q.8 Deforestation contributes to global warming primarily because it:
Reduces soil erosion
Decreases carbon storage
Increases rainfall
Enhances biodiversity
Explanation - Trees absorb CO2; cutting them down reduces carbon storage, increasing atmospheric CO2 and contributing to global warming.
Correct answer is: Decreases carbon storage
Q.9 Which of the following is a major consequence of ocean acidification?
Melting glaciers
Coral bleaching
Deforestation
Ozone depletion
Explanation - Ocean acidification lowers pH levels, stressing corals and leading to coral bleaching.
Correct answer is: Coral bleaching
Q.10 Which international agreement aims to limit global temperature rise to below 2°C?
Montreal Protocol
Paris Agreement
Kyoto Protocol
Geneva Convention
Explanation - The Paris Agreement (2015) aims to limit global warming to well below 2°C above pre-industrial levels.
Correct answer is: Paris Agreement
Q.11 Which human activity contributes most to biodiversity loss?
Agriculture expansion
Space exploration
Fishing for sport
Painting landscapes
Explanation - Clearing land for agriculture destroys natural habitats, leading to significant biodiversity loss.
Correct answer is: Agriculture expansion
Q.12 Which of the following is a renewable energy source?
Coal
Natural Gas
Solar
Petroleum
Explanation - Solar energy is renewable as it comes from the sun and is sustainable for long-term use.
Correct answer is: Solar
Q.13 Eutrophication in water bodies is primarily caused by:
Excess nutrients
Oil spills
Plastic waste
Overfishing
Explanation - Runoff containing nitrogen and phosphorus from fertilizers leads to nutrient overload, causing eutrophication.
Correct answer is: Excess nutrients
Q.14 Which of these gases has the highest global warming potential per molecule?
CO2
Methane
Nitrous Oxide
Water Vapor
Explanation - Nitrous oxide (N2O) is far more effective per molecule at trapping heat compared to CO2 and methane.
Correct answer is: Nitrous Oxide
Q.15 Which is a direct effect of melting polar ice caps?
Increased agricultural land
Rising sea levels
Decreased ocean salinity
Increased forest cover
Explanation - Melting polar ice adds water to oceans, causing sea levels to rise and threatening coastal areas.
Correct answer is: Rising sea levels
Q.16 Which practice helps in combating soil erosion?
Overgrazing
Deforestation
Contour farming
Mining
Explanation - Contour farming involves plowing along the natural contours of land to reduce water runoff and soil erosion.
Correct answer is: Contour farming
Q.17 Which is considered the most effective long-term solution to reduce global warming?
Planting trees
Using coal power
Increasing fossil fuel consumption
Deforestation
Explanation - Trees absorb CO2, helping reduce greenhouse gas levels and mitigating global warming.
Correct answer is: Planting trees
Q.18 The 'Tragedy of the Commons' is an environmental concept that describes:
Overuse of shared resources
Protection of endangered species
Sustainable energy use
Rainforest conservation
Explanation - It refers to the depletion of common resources due to individual self-interest, harming the collective good.
Correct answer is: Overuse of shared resources
Q.19 Which environmental problem is mainly caused by industrial emissions and traffic?
Water pollution
Air pollution
Deforestation
Desertification
Explanation - Industrial emissions and vehicle exhaust release pollutants into the air, causing air pollution.
Correct answer is: Air pollution
Q.20 Which of these is a consequence of melting glaciers?
Reduced water availability
Ozone layer repair
Increased forest cover
Soil enrichment
Explanation - Melting glaciers reduce freshwater storage, impacting water availability for humans and ecosystems.
Correct answer is: Reduced water availability
Q.21 Which is the primary source of microplastics in oceans?
Synthetic fibers
Tree leaves
Sand
Natural stones
Explanation - Microplastics mainly come from synthetic clothing fibers and plastic waste that degrade in water.
Correct answer is: Synthetic fibers
Q.22 Which is the leading cause of coral reef degradation?
Overfishing and warming oceans
Soil erosion
Deforestation
Ozone depletion
Explanation - Coral reefs are highly sensitive to temperature rise and are also damaged by overfishing practices.
Correct answer is: Overfishing and warming oceans
Q.23 Which gas is released in large quantities by livestock and contributes to greenhouse effect?
Methane
Carbon Dioxide
Nitrogen
Oxygen
Explanation - Livestock produce methane (CH4) through enteric fermentation, a potent greenhouse gas contributing to climate change.
Correct answer is: Methane
Q.24 Which global environmental issue is most directly related to the use of fossil fuels?
Global warming
Ozone layer depletion
Acid rain
Deforestation
Explanation - Burning fossil fuels releases CO2, the main greenhouse gas responsible for global warming.
Correct answer is: Global warming
Q.25 Which of the following is an example of a transboundary environmental issue?
Air pollution from one country affecting another
Local park littering
Household waste disposal
City traffic congestion
Explanation - Transboundary issues are environmental problems that cross national borders, such as air pollution or river pollution.
Correct answer is: Air pollution from one country affecting another