The manuscript is much improved.

There is one issue raised by Reviewer 2 that I think the authors need to clarify and possibly reconsider. This is the discussion about changes in the ratio of C2H4 and CO at JPL over time which is in lines 212-216 and the interpretation of Fig 5a and part of Table 1.

The main point is that it is not clear exactly what the authors are calculating: (a) is the correlation coefficient calculated on the raw measurements or after the sample means are taken out?; (b) is the gradient calculated on a line forced through zero or is an non-zero intercept allowed? If a non-zero intercept is allowed, then the discussion about the background C2H4 is moot, as an effective background of about 1.5E18 for CO is found from the data. (By definition we can assume that background occurs when C2H4=0 if we are considering sources that emit both CH2H4 and CO.) What is then interesting is if the slope of lines - or the intercepts - calculated for different time periods changing as that implies a change in the emission ratio.

So my recommendation is that the authors (a) clarify exactly what they have calculated in the text and in Table 1, e.g. by drawing a fitted line in Fig5a; (b) adjust the text accordingly. Either way the changes are minor in terms of effort, but this is central to the conclusions.

Minor:
134: Figure 3 shows....

That is much clearer. I could not find the tables in the supplementary information. Can you upload them so that I have a look before accepting?