Carbon Flux & Human Impact

What is the primary reason for the increase in atmospheric CO2 levels over the past 100 years?

• Increased volcanic activity

• Human activities such as burning fossil fuels and deforestation

• Natural carbon cycle processes

• Increased solar radiation

Which of the following spheres has the largest carbon storage?

• Atmosphere

• Biosphere

• Hydrosphere

• Lithosphere

How much carbon is exchanged annually between the atmosphere and the hydrosphere?

• 50 GT

• 70 GT

• 90 GT

• 110 GT

During which historical period did human activity begin significantly increasing atmospheric CO2 levels?

• The Renaissance

• The Industrial Revolution

• The Middle Ages

• The Information Age

What is the current annual contribution of carbon to the atmosphere from fossil fuel burning?

• 2–4 GT

• 5–7 GT

• 8–10 GT

• 10 GT

Which human activity contributes 2–4 gigatons of carbon per year to the atmosphere?

• Fossil fuel burning

• Deforestation and agriculture

• Industrial manufacturing

• Urbanization

What is the main reason that atmospheric CO2 levels continue to rise?

• Increased plant photosynthesis

• Lack of processes returning CO2 to other spheres

• Decreased ocean absorption

• Increased animal respiration

Which two spheres exchange the greatest amount of carbon annually?

• Atmosphere and lithosphere

• Biosphere and hydrosphere

• Biosphere and atmosphere

• Atmosphere and hydrosphere

The primary source of carbon added to the atmosphere from the lithosphere is (a)  

• Volcanic eruptions
• Fossil fuel combustion
• Soil erosion
• Oceanic release

How has human population growth affected carbon fluxes?

• Decreased carbon emissions

• Increased carbon emissions

• No effect on carbon emissions

• Stabilized carbon emissions