CO2 and Temperature concentration in the atmosphere over the past 400,000 years (from the Vostok ice core)

The graph shows that CO2 concentration and Temperature is directly correlated. When the CO2 concentration goes up, the temperature goes up. The highest concentration of CO2 was reached 325,000 years ago and reached 300 ppmv. The highest tempurature was reached during the same time and was 2oC. Other pertinent information is described in the paragraph below the image.