diff --git a/pyaerocom/data/variables.ini b/pyaerocom/data/variables.ini
index 68a566a35..b70c0df95 100644
--- a/pyaerocom/data/variables.ini
+++ b/pyaerocom/data/variables.ini
@@ -3027,6 +3027,16 @@ maximum = 100000000
 dimensions = time,lat,lon
 comments_and_purpose = Major HTAP output diagnostic: Air Quality and Impact analysis
 
+[vmrco2]
+var_name = vmrco2
+description = CO2 Volume Mixing Ratio
+standard_name = mole_fraction_of_carbon_dioxide_in_air
+var_type = volume mixing ratios
+unit = nmol mol-1
+minimum = 0
+maximum = 100000000
+dimensions = time,lat,lon
+
 [vmrhno3]
 var_name = vmrhno3
 description = HNO3 Volume Mixing Ratio