Carbon Budget Practice Questions
20 free Carbon Budget practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
The carbon budget refers to:
- A Total amount of carbon stored permanently in Earth's crust
- B Balance between carbon emissions and carbon absorption
- C Annual estimate of fossil fuel reserves worldwide
- D Amount of carbon present only in the atmosphere at one time
Correct answer: Balance between carbon emissions and carbon absorption
The carbon budget represents the balance between carbon released into the atmosphere and carbon removed by sinks. It is crucial for limiting global temperature rise.
Which of the following is the largest natural carbon reservoir?
- A Atmosphere
- B Ocean waters
- C Terrestrial vegetation
- D Fossil fuel deposits
Correct answer: Ocean waters
Oceans store the largest amount of carbon, mainly as dissolved inorganic carbon. They play a major role in regulating atmospheric CO2.
Which human activity contributes most to the increase in atmospheric CO2?
- A Land-use deforestation
- B Industrial agriculture
- C Burning of fossil fuels
- D Underground mining operations
Correct answer: Burning of fossil fuels
Burning fossil fuels releases large amounts of carbon dioxide. This is the primary driver of increased atmospheric CO2 levels.
Carbon sinks are components of the Earth system that:
- A Release carbon into the atmosphere continuously
- B Convert carbon into molecular oxygen
- C Store more carbon than they release
- D Prevent all carbon emissions from ecosystems
Correct answer: Store more carbon than they release
Carbon sinks absorb more carbon than they emit. Forests, soils, and oceans are major carbon sinks.
Which process removes carbon dioxide from the atmosphere naturally?
- A Respiration
- B Combustion
- C Photosynthesis
- D Volcanic eruption
Correct answer: Photosynthesis
Photosynthesis fixes atmospheric CO2 into organic compounds. This process is a key component of the global carbon cycle.
Global climate change is primarily driven by an increase in:
- A Ozone concentration
- B Greenhouse gases
- C Solar radiation
- D Earth’s magnetic field
Correct answer: Greenhouse gases
Greenhouse gases trap heat in the atmosphere. Increased concentrations enhance the greenhouse effect, leading to global warming.
Which greenhouse gas has the highest contribution to anthropogenic global warming?
- A Methane gas
- B Nitrous oxide
- C Carbon dioxide
- D Tropospheric ozone
Correct answer: Carbon dioxide
Carbon dioxide is emitted in the largest quantities by human activities. It has a long atmospheric lifetime and major warming impact.
Deforestation affects the carbon budget mainly by:
- A Increasing photosynthesis
- B Reducing carbon sinks
- C Enhancing ocean uptake
- D Lowering respiration rates
Correct answer: Reducing carbon sinks
Deforestation reduces the number of trees that absorb CO2. This decreases carbon sequestration and increases atmospheric carbon.
The term carbon sequestration refers to:
- A Release of carbon into air
- B Conversion of carbon into methane
- C Long-term storage of carbon
- D Rapid cycling of carbon
Correct answer: Long-term storage of carbon
Carbon sequestration involves capturing and storing carbon for long periods. It helps reduce atmospheric CO2 levels.
Which ecosystem has the highest carbon storage per unit area?
- A Temperate grasslands
- B Tropical rainforests
- C Hot and dry deserts
- D Arctic tundra regions
Correct answer: Tropical rainforests
Tropical rainforests store large amounts of carbon in biomass. They play a critical role in the global carbon budget.
Ocean acidification is directly linked to:
- A Increased nitrogen and sulfur deposition from rain
- B Absorption of atmospheric CO2 by seawater
- C Rising surface sea temperature globally
- D Accelerated melting of polar ice caps
Correct answer: Absorption of atmospheric CO2 by seawater
Oceans absorb excess CO2, forming carbonic acid. This lowers seawater pH and leads to ocean acidification.
Which of the following best explains the greenhouse effect?
- A Reflection of incoming sunlight by clouds
- B Absorption and re-emission of heat by atmospheric gases
- C Complete blocking of all solar radiation by the atmosphere
- D Net cooling effect on Earth's surface by the atmosphere
Correct answer: Absorption and re-emission of heat by atmospheric gases
Greenhouse gases absorb outgoing infrared radiation and re-radiate it. This process warms the Earth's surface.
The remaining allowable CO2 emissions to limit warming to a specific target are called:
- A Carbon reserve
- B Carbon footprint
- C Carbon budget
- D Carbon cycle
Correct answer: Carbon budget
The carbon budget defines how much more CO2 can be emitted while staying within a temperature limit. It guides climate mitigation strategies.
Which feedback mechanism accelerates global warming?
- A Increased photosynthesis
- B Ice-albedo feedback
- C Carbon sequestration
- D Cloud reflection
Correct answer: Ice-albedo feedback
Melting ice reduces surface reflectivity. This causes more heat absorption, accelerating warming.
Soil acts as a carbon sink mainly through:
- A Microbial respiration processes
- B Breakdown by decomposition
- C Storage of organic matter
- D Chemical weathering of minerals
Correct answer: Storage of organic matter
Soils store carbon in organic matter such as humus. This storage is an important component of the terrestrial carbon budget.
Which international agreement aims to limit global temperature rise by managing carbon emissions?
- A Montreal Protocol
- B Paris Agreement
- C Ramsar Convention
- D CITES Wildlife Treaty
Correct answer: Paris Agreement
The Paris Agreement focuses on reducing greenhouse gas emissions. It aims to keep global warming well below 2°C.
Which factor reduces the efficiency of oceans as carbon sinks?
- A Lower ocean temperatures
- B Increased phytoplankton growth and productivity
- C Ocean warming
- D Deep-water upwelling currents
Correct answer: Ocean warming
Warmer oceans hold less dissolved CO2. This reduces their capacity to absorb atmospheric carbon.
Which land-use practice enhances carbon storage?
- A Urban expansion
- B Afforestation
- C Livestock overgrazing
- D Slash-and-burn agriculture
Correct answer: Afforestation
Afforestation increases tree cover and biomass. This enhances carbon sequestration on land.
Which component of the carbon cycle directly links ecosystems and climate?
- A Nitrogen fixation by soil microbes
- B Carbon fluxes between biosphere and atmosphere
- C The hydrological water cycle
- D Mineral weathering and erosion processes
Correct answer: Carbon fluxes between biosphere and atmosphere
Carbon exchange between ecosystems and the atmosphere influences climate. Changes in these fluxes affect atmospheric CO2 levels.
Which statement best summarizes the relationship between carbon budget and global climate change?
- A Carbon budget is unrelated to any aspect of climate
- B Carbon budget determines allowable emissions to limit warming
- C Climate change automatically reduces global carbon emissions
- D Carbon budget applies only to ocean carbon dynamics
Correct answer: Carbon budget determines allowable emissions to limit warming
The carbon budget sets limits on cumulative CO2 emissions. Staying within it is essential to control global climate change.