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| Titel |
Recent revisions of phosphate rock reserves and resources: a critique |
| VerfasserIn |
J. D. Edixhoven, J. Gupta, H. H. G. Savenije |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2190-4979
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| Digitales Dokument |
URL |
| Erschienen |
In: Earth System Dynamics ; 5, no. 2 ; Nr. 5, no. 2 (2014-12-19), S.491-507 |
| Datensatznummer |
250115378
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| Publikation (Nr.) |
 copernicus.org/esd-5-491-2014.pdf |
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| Zusammenfassung |
| Phosphate rock (PR) is a finite mineral indispensable for fertilizer
production, while P (phosphorus) is a major pollutant if applied or discharged
in excess, causing widespread eutrophication (Carpenter and Bennet, 2011).
High-grade PR is obtained from deposits which took millions of years to form
and which are gradually being depleted. Recently, global PR reserves as
reported by the US Geological Survey (USGS) have increased from
16 000 Mt PR in 2010 to 65 000 Mt PR in 2011 and further to
67 000 Mt PR in 2014. The majority of this 4-fold increase is based on
a 2010 report by the International Fertilizer Development Center (IFDC),
which increased Moroccan reserves from 5700 Mt PR as reported by USGS, to
51 000 Mt PR, reported as upgraded ("beneficiated") concentrate. The
report also increased global resources from 163 000 Mt PR reported in the
literature in 1989 to 290 000 Mt PR. IFDC used a simplified resource
terminology which does not use the underlying thresholds for reserves and
resources used in the USGS classification. IFDC proposed that agreement
should be reached on PR resource terminology which should be as simple as
possible. The report has profoundly influenced the PR scarcity debate,
shifting the emphasis from resource scarcity to the pollution angle of the
phosphate problem. In view of the high dependence of food production on PR
and the importance of data on PR reserves and resources for scientific
analysis and policy making, data on PR deposits should be transparent,
comparable, reliable, and credible. We analyze (i) how IFDC's simplified
terminology compares to international best practice in resource
classification and whether it is likely to yield data that meet these
requirements, (ii) whether the difference in volume between raw PR ore and
upgraded PR concentrate is sufficiently noted in the literature, and (iii) whether
the IFDC report presents an accurate picture of PR reserves and
resources. We conclude that, while there is a global development toward
common criteria in resource reporting, IFDC's lack of clear thresholds for
reserves and resources contravenes this and that the vagueness of its
definitions for reserves and resources may allow deposits to be termed
reserves or resources which could not be recognized as such under leading
mineral resource classifications. The difference between PR ore and PR
concentrate is barely noted in the literature, causing pervasive confusion
and a significant degree of error in many assessments. Finally, we find that
the report most likely presents an inflated picture of global reserves, in
particular those of Morocco, where the aggregate resources of three of the
four Moroccan/Western Saharan major PR deposits appear to have been simply
converted to "reserves". Following the release of the IFDC report, various
analysts have concluded or suggested that the available PR deposits or even
the currently reported resources would likely last several thousands of years
at current consumption rates. However, the data on which these statements
were based do not appear to warrant such a conclusion. Further research is
required as to the quantity of PR deposits and their viability for future
extraction, using uniform and transparent classification terminology. |
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