6. Considering the graph and what you have learned in the lessons, how would you suspect the concentration of carbon dioxide and methane in the atmosphere to have changed over the past 100 years?

The concentrations of these gases have probably increased.

The concentrations of these gases have probably decreased.

The concentrations of these gases have probably stayed the same.

The concentrations of these gases are not related to the temperature changes.

The concentrations of these gases have probably increased.