Dear authors,

Your comment has now been reviewed by an additional reviewer, a geologist, who is not directly involved in the discussion on phosphorus reserves. This outside view found your comment to be very good and justified, so I placed extra weight at this outside view and decided that your manuscript is acceptable after minor revisions.

The reviewer also raised a few points, particularly regarding some formulations in reference to the Edixhoven paper. I fully agree with the reviewer on the goal of focussing on a more productive and objective debate. I ask you to address these points in a revision and have this goal in mind.

When you submit your revised version, please submit this with the modifications being clearly marked (ideally using "track changes") with a cover letter.

I am looking forward to your revised manuscript.

Best regards,
Axel Kleidon

Dear authors,

I have now read through your material and evaluated how well it accommodated the changes pointed out by reviewer Buechel. I actually found it rather disappointing to see (and difficult to understand) how little effort you put into the revision to accommodate the reviewer's request to make the text more objective and less discrediting. The manuscript really gives the impression that there is nothing worthwhile about the Edixhoven et al. manuscript, even though you commented on it yourself in your reply to the review by saying "A major achievement of the Edixhoven et. al (2014) paper is that it identified the sloppy use the mixing of PR-M and PR Ore in the USGS mineral survey data."

I therefore return this manuscript to you for yet another round of revision and ask you to make a sincere effort to make the references to Edixhoven et al. more objective.

I am looking forward to your revised version, which is then hopefully suitable for acceptance.

Best regards,
Axel Kleidon

Dear authors,

I have now read through your revised manuscript and acknowledge that you altered some places of the manuscript to a more moderate tone. I have now accepted the comment for publication.

I found one minor point for correction in Figure 1. It contains a yellow box "Diagrammbereich" that should be removed. Please adjust this when you submit the final figures.

Kind regards,
Axel Kleidon