Pre-Read Isotopes and Atmosphere

​Look at the graph:

1. ​What is on the x-axis? y-axis?

2. What is the trend?

Multiple Choice

What does the graph measure?

• Changes in CO₂ over time

• Changes in temperature over time

• Changes in sea level over time

• Change in time over the years

Multiple Choice

How is CO₂ most often been measured?

• Sensors on Mauno Loa

• From weather balloons

• By satellites

• From ice cores

​Look at the graph

This graph is measuring concentration of carbon-13 in the atmosphere.

Multiple Choice

Does this data come from only 1 ice core?

• yes

• no

Multiple Choice

Over time, what has happened to the concentration of carbon-13 in the atmosphere.

• Carbon-13 has increased.

• Carbon-13 has decreased.

Dropdown

Since the 1800's, as CO₂ has increased, the percent of ¹³C has​

Select answer

Multiple Choice

Since CO₂ is increasing, but ¹³C is decreasing, what does that mean?

• There is more ¹²C - CO₂ being produced.

• There is less CO₂ being produced.

• There is more photosynthesis occuring.

• There is more ¹³C - CO₂ being produced.