2.2.4 CO Sinks

The major removal process for CO in the atmosphere is its reaction with OH:

The value quoted in Table 2.1 for the removal uses a global average OH density of 6 E+5 /cm³. If the upper limits for the various sources shown in Table 2.1 apply it is clear that a higher average OH value will be more appropriate.

CO may also be taken up by soils, but it appears that this represents a relatively minor sink.