Keeling Curve INTRO

In ​ (a)   Charles​ (b)   began measuring​ (c)   levels from Hawaii's Mauna Loa volcano.

• 1958
• Keeling
• CO2
• 1972
• Darwin
• oxygen

Please propose a hypothesis that explains the seasonal variation in CO2 levels.

The ​ (a)   curve show CO₂ levels in 1958 of ​ (b)   rising to ​ (c)   in 2014.

• Keeling
• 318 ppm
• 402 ppm
• Wheeler
• 115 ppm
• 645 ppm

In your own words, what is the significance of Keeling's Curve?