Question if we find that there is a linear correlation between the concentration of carbon dioxide in our atmosphere and the global temperature, does that indicate that changes in the concentration of carbon dioxide cause changes in the global temperature

Yes.

Carbondioxide affects changes in temperature because carbondioxide in the air absorb infrared radiation. When concentration of carbondioxide is high or low, absorption band become effective and alot of infared radiation is absorbed. Carbondioxide blankets prevent infared Ray's from escaping into space, the absorbed ones warm up the atmosphere. As carbondioxide is use for photosynthesis, the content of carbondioxide changes in the atmosphere which intend shift the radiation balance i.e carbondioxide may not be able to absorb more infared radiation which can lead to increase or decrease of Earth's temperature.

Explanation:

Carbondioxide can affect the global temperature. Carbondioxide absorb infared radiation and this have effect on global temperature.

oxygen +1 most likely