Answer: Temperature before the increase in [tex]CO_2[/tex] was a few degrees lower than temperature after the increase.
Explanation:
According to Charle's Law which states that The volume of gas is directly proportional to the temperature of the gas, when pressure is kept constant.
[tex](Volume)\propto (Temperature)[/tex]
[tex]\frac{volume}{temperature}=constant[/tex] (At constant Pressure)
With the increase in level [tex]CO_2[/tex] in atmosphere the increase in temperature of the atmosphere will be observed.
Hence, temperature before the increase in [tex]CO_2[/tex] was a few degrees lower than temperature after the increase.