Methods and results of the Kinetics of Chlorite Dissolution at Elevated Temperatures and CO2 Conditions are described and discussed in the paper. Data from this experiment is included as a downloadable .xlsx spreadsheet in the linked GDR submission. Chlorite dissolution kinetics were measured under far from equilibrium conditions using a mixed-flow reactor over temperatures of 100-275 degrees C at pH values of 3.0-5.7 in a background solution matrix of 0.05 m NaCl. Over this temperature range, magnesium was released congruently with respect to silica. The effect of variable pCO2 levels representative of engineered geothermal systems with CO2 as a heat-exchanging fluid (CO2-EGS) was explored by reacting chlorite with solutions containing a range of dissolved CO2 concentrations (0.1-0.5 M).