When Looking at the Atmospheric CO₂ Concentrations Collected from Ice

question 14

Multiple Choice

When looking at the atmospheric CO₂ concentrations collected from ice core layers over the last 500,000 years, what does one see?

• A) an ever-increasing level of CO₂ from 500,000 years before the present (BP) to today
• B) an ever-decreasing level of CO₂ from 500,000 years BP until 150,000 years BP and then a steady rise until today
• C) a varying level of CO₂ from 500,000 years BP to today
• D) no change in the level of CO₂ from 500,000 years BP until just recently (the last 100 years of human history)

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Definitions:

River's Flow

The movement of water in a river channel as it travels from the headwaters to the mouth, influenced by gravity and landscape.

Gravity

The force that attracts a body towards the center of the earth, or towards any other physical body having mass, playing a key role in the movement and deformation of the Earth's crust.

Sediment Load

The amount of sediment, including material chemically dissolved in a solution, carried by a stream.

Clasts

Rock fragments or grains that are cemented together in a sedimentary rock.