Hi Arno,

I have now added the four links that you had mentioned to the links list in the sticky post. For the other books and journal papers that you listed listed, I don't think they would really qualify to be in the Top-5 list for newcomers to the topic, so I didn't include them.

The more I look at these links and articles, the more I think that the role that sustainable sanitation could play in "averting" this looming phosphorus crisis/shortage is actually only very small. It seems that there are many other issues that are more significant and pressing, like the way P-fertiliser is used in agriculture or how animal manure is managed, and of course the whole politics around this (with only few countries sitting on the mines of P reserves).

This is also evident from the topics in the Google Discussion group on sustainable phosphorus that you manage:
groups.google.com/forum/#!forum/sustainablephosphorusplatform

Regards,
Elisabeth

Yes the two books (Wyant et al. 2013) and (Butusov & Jernelöv, 2013) are much more comprehensive than the three references you have as recommended reading. The special issue of Springer's Journal, Nutrient Cycling in Agroecosystems is a collection of refereed papers on the topic.

Last month (Jan 2016) a Special Issue on Sustainable Phosphorus came out in Science of the Total Environment. The list of papers with links to them is found here:

groups.google.com/forum/?hl=en#!topic/su...platform/5cPsPvMTRe0

For those that do not have rights to access published papers online that are not open access, I would take direct contact with the authors and request a PDF of the author's copy.

Science of The Total Environment, Volume 542, Part B, 15 January 2016, Page IFC, ISSN 0048-9697, dx.doi.org/10.1016/S0048-9697(15)00699-3.

(www.sciencedirect.com/science/article/pii/S0048969715006993)

Andrea E.Ulrich, Taking Stock: Phosphorus Supply from Natural and Anthropogenic Pools in the 21st Century, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1005-1007, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.10.036.
(www.sciencedirect.com/science/article/pii/S0048969715308524)
Keywords: Phosphorus; Supply risk; Scarcity; Recycling; Food security; Environmental health; Residual soil phosphorus century

M.C. Mew, Phosphate rock costs, prices and resources interaction, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1008-1012, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.08.045.
(www.sciencedirect.com/science/article/pii/S0048969715305489)
Abstract:
This article gives the author's views and opinions as someone who has spent his working life analyzing the international phosphate sector as an independent consultant. His career spanned two price hike events in the mid-1970's and in 2008, both of which sparked considerable popular and academic interest concerning adequacy of phosphate rock resources, the impact of rising mining costs and the ability of mankind to feed future populations. An analysis of phosphate rock production costs derived from two major industry studies performed in 1983 and 2013 shows that in nominal terms, global average cash production costs increased by 27% to $38 per tonne fob mine in the 30 year period. In real terms, the global average cost of production has fallen. Despite the lack of upward pressure from increasing costs, phosphate rock market prices have shown two major spikes in the 30 years to 2013, with periods of less volatility in between. These price spike events can be seen to be related to the escalating investment cost required by new mine capacity, and as such can be expected to be repeated in future. As such, phosphate rock price volatility is likely to have more impact on food prices than rising phosphate rock production costs. However, as mining costs rise, recycling of P will also become increasingly driven by economics rather than legislation.
Keywords: Phosphate; Phosphorus; Fertilizer; Resources; Costs; Prices; Recycling

Sylvia Kratz, Judith Schick, Ewald Schnug, Trace elements in rock phosphates and P containing mineral and organo-mineral fertilizers sold in Germany, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1013-1019, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.08.046.
(www.sciencedirect.com/science/article/pii/S0048969715305490)
Abstract
68 rock phosphates and 162 P containing (organo-)mineral fertilizers sold in Germany were evaluated with regard to trace element contents. While Al, As, B, Be, Cd, Cr, Mo, Ni, Pb, Sb, Se, Tl, U, and Zn were higher in sedimentary than in igneous rock phosphates, the opposite was true for Co, Cu, Sn, Mn, Ti, Fe, and Sr. Comparing element concentrations to the currently valid legal limit values defined by the German Fertilizer Ordinance, it was found that some PK and many straight P fertilizers (superphosphate, triple superphosphate, partly acidulated rock phosphates) exceeded the limit of 50 mg Cd/kg P2O5. Mean values for As, Ni, Pb, and Tl remained below legal limits in almost all cases. While no legal limit has been defined for U in Germany yet, the limit of 50 mg U/kg P2O5 for P containing fertilizers proposed by the German Commission for the Protection of Soils was clearly exceeded by mean values for all fertilizer types analyzed. A large share of the samples evaluated in this work contained essential trace elements at high concentrations, with many of them not being declared as such. Furthermore, trace elements supplied with these fertilizers at a fertilization rate leveling P uptake would exceed trace element uptake by crops. This may become most relevant for B and Fe, since many crops are sensitive to an oversupply of B, and Fe loads exceeding plant uptake may immobilize P supplies for the crops by forming Fe phosphate salts. The sample set included two products made from thermochemically treated sewage sludge ash. The products displayed very high concentrations of Fe and Mn and exceeded the legal limit for Ni, emphasizing the necessity to continue research on heavy metal removal from recycled raw materials and the development of environmentally friendly and agriculturally efficient fertilizer products.
Keywords: Rock phosphates; Mineral P fertilizers; Trace elements; Heavy metals

Wenbo Xie, Dongye Zhao, Controlling phosphate releasing from poultry litter using stabilized Fe–Mn binary oxide nanoparticles, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1020-1029, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.09.063.
(www.sciencedirect.com/science/article/pii/S0048969715307233)
Abstract
Animal wastes contain high concentrations of phosphorus (P), most of which is lost into the environment due to uncontrolled release rates. Polysaccharide stabilized Fe–Mn binary oxide nanoparticles were prepared and tested for phosphate adsorption from water and for controlling leachability of P from poultry litter. A water soluble starch and carboxymethyl cellulose (CMC) were used as a stabilizer. Both the Freundlich and Langmuir models were able to adequately interpret the isotherm data. The Langmuir maximum capacity was determined at 252, 298 and 313 mg-P/g for bare, CMC- and starch-stabilized nanoparticles, respectively. The presence of the stabilizers not only enhanced the sorption capacity, but facilitated delivery and dispersion of the nanoparticles in poultry litter (PL) and in soil. High phosphate sorption capacity was observed over a broad pH range of 4–9. FTIR analyses indicated that inner sphere surface complexation (Fe–O–P) was the key mechanism for the enhanced uptake of P. When applied to poultry litter, the stabilized nanoparticles reduced water leachable phosphate by > 86% at a dose of 0.2 g/L as Fe, and simultaneously, water leachable arsenic by > 87–95%. Under conditions of simulated land application of PL, the nanoparticle amendment of PL reduced the water soluble P from 66% (for untreated PL) to 4.4%, and lowered the peak soluble P concentration from 300 to < 20 mg/L. By transferring the peak soluble P to the nanoparticle-bound P, the nanoparticles not only greatly reduce the potential runoff loss of P from PL, but also provide a long-term slow-releasing nutrient source. Fortuitously, the nanoparticle treatment was able to immobilize arsenic from PL. With excellent adsorption capacity, easy deliverability, low cost and environmental innocuousness, the stabilized Fe–Mn nanoparticles appear promising for controlling P releases from poultry litter or other animal wastes and for phosphate recovery from water.
Keywords: Nutrient; Phosphorus; Phosphate; Arsenic; Nanoparticle; Poultry litter

Andrea E. Ulrich, Diane F. Malley, Paul D. Watts, Lake Winnipeg Basin: Advocacy, challenges and progress for sustainable phosphorus and eutrophication control, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1030-1039, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.09.106.
(www.sciencedirect.com/science/article/pii/S004896971530766X)
Abstract
Intensification of agricultural production worldwide has altered cycles of phosphorus (P) and water. In particular, loading of P on land in fertilizer applications is a global water quality concern. The Lake Winnipeg Basin (LWB) is a major agricultural area displaying extreme eutrophication. We examined the eutrophication problem in the context of the reemerging global concern about future accessibility of phosphate rock for fertilizer production and sustainable phosphorus management. An exploratory action research participatory design was applied to study options for proactivity within the LWB. The multiple methods, including stakeholder interviews and surveys, demonstrate emerging synergies between the goals of reversing eutrophication and promoting food security. Furthermore, shifting the prevalent pollutant-driven eutrophication management paradigm in the basin toward a systemic, holistic and ecocentric approach, integrating global resource challenges, requires a mutual learning process among stakeholders in the basin to act on and adapt to ecosystem vulnerabilities. It is suggested to continue aspects of this research in a transdisciplinary format, i.e., science with society, in response to globally-expanding needs and concerns, with a possible focus on enhanced engagement of indigenous peoples and elders.
Keywords: Phosphorus; Eutrophication; Nutrient management; Water management; Action research; Lake Winnipeg; Indigenous

Raphael A. Viscarra Rossel, Elisabeth N. Bui, A new detailed map of total phosphorus stocks in Australian soil, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1040-1049, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.09.119.
(www.sciencedirect.com/science/article/pii/S0048969715307804)
Abstract
Accurate data are needed to effectively monitor environmental condition, and develop sound policies to plan for the future. Globally, current estimates of soil total phosphorus (P) stocks are very uncertain because they are derived from sparse data, with large gaps over many areas of the Earth. Here, we derive spatially explicit estimates, and their uncertainty, of the distribution and stock of total P in Australian soil. Data from several sources were harmonized to produce the most comprehensive inventory of total P in soil of the continent. They were used to produce fine spatial resolution continental maps of total P in six depth layers by combining the bootstrap, a decision tree with piecewise regression on environmental variables and geostatistical modelling of residuals. Values of percent total P were predicted at the nodes of a 3-arcsecond (approximately 90 m) grid and mapped together with their uncertainties. We combined these predictions with those for bulk density and mapped the total soil P stock in the 0–30 cm layer over the whole of Australia. The average amount of P in Australian topsoil is estimated to be 0.98 t ha− 1 with 90% confidence limits of 0.2 and 4.2 t ha− 1. The total stock of P in the 0–30 cm layer of soil for the continent is 0.91 Gt with 90% confidence limits of 0.19 and 3.9 Gt. The estimates are the most reliable approximation of the stock of total P in Australian soil to date. They could help improve ecological models, guide the formulation of policy around food and water security, biodiversity and conservation, inform future sampling for inventory, guide the design of monitoring networks, and provide a benchmark against which to assess the impact of changes in land cover, land use and management and climate on soil P stocks and water quality in Australia.
Keywords: Total phosphorus; Phosphorus stocks; Predictive modelling; Digital soil mapping; Phosphorus cycling

Marcos Rodrigues, Paulo Sergio Pavinato, Paul John Anthony Withers, Ana Paula Bettoni Teles, Wilfrand Ferney Bejarano Herrera, Legacy phosphorus and no tillage agriculture in tropical oxisols of the Brazilian savanna, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1050-1061, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.08.118.
(www.sciencedirect.com/science/article/pii/S0048969715306197)
Abstract
Crop production in the Brazilian Cerrado is limited by soil phosphorus (P) supply without large inputs of inorganic P fertilizer, which may become more costly and scarce in the future. Reducing dependency on fertilizer P requires a greater understanding of soil P supply in the highly weathered soils in this important agricultural region. We investigated the impact of no tillage (NT) and conventional tillage (CT) agriculture on accumulated (legacy) soil P and P forms in four long-term sites. Compared to the native savanna soils, tilled soils receiving regular annual P fertilizer inputs (30–50 kg P ha− 1) increased all forms of inorganic and organic P, except highly recalcitrant P associated with the background lithology. However, 70–85% of the net added P was bound in moderately labile and non-labile forms associated with Fe/Al oxyhydroxides rather than in plant available forms. Under NT agriculture, organic P forms and labile and non-labile inorganic P forms were all significantly (P < 0.05) increased in the surface soil, except for one site with maize residues where labile inorganic P was increased more under CT agriculture. The contribution of organic P cycling in these tropical soils increased after conversion to agriculture and was proportionally greater under NT. The results highlight the large amounts of unutilized legacy P present in Brazil's Cerrado soils that could be better exploited to reduce dependency on imports of finite phosphate rock. No tillage agriculture confers a positive albeit relatively small benefit for soil P availability and overall soil function.
Keywords: Phosphorus fractionation; Inorganic P; Organic P; No tillage; Cerrado; Brazilian savanna

Remigiusz Łukowiak, Witold Grzebisz, Gretchen F. Sassenrath, New insights into phosphorus management in agriculture — A crop rotation approach, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1062-1077, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.09.009.
(www.sciencedirect.com/science/article/pii/S0048969715306690)
Keywords: Oil seed rape; Maize; Calcium chloride extractable phosphorus; Soil profile; Soil system phosphorus budget

Kimo C. van Dijk, Jan Peter Lesschen, Oene Oenema, Phosphorus flows and balances of the European Union Member States, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1078-1093, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.08.048.
(www.sciencedirect.com/science/article/pii/S0048969715305519)
Abstract
Global society faces serious “phosphorus challenges” given the scarcity, essentiality, unequal global distribution and, at the same time, regional excess of phosphorus (P). Phosphorus flow studies can be used to analyze these challenges, providing insight into how society (re)uses and loses phosphorus, identifying potential solutions.

Phosphorus flows were analyzed in detail for EU-27 and its Member States. To quantify food system and non-food flows, country specific data and historical context were considered. The sectors covered were crop production (CP), animal production (AP), food processing (FP), non-food production (NF) and consumption (HC).

The results show that the EU-27 imported 2392 Gg P in 2005, half of which accumulated in agricultural soils (924 Gg) and half was lost as waste (1217 Gg). Net accumulation was 4.9 kg P/ha/year ranging between + 23.2 (Belgium) and − 2.8 (Slovakia). From the system losses, 54% was lost from HC in diverse waste flows and 28% from FP, mainly through incinerated slaughter residues. The largest HC losses (655 Gg) were wastewater (55%), food waste (27%), and pet excreta (11%). Phosphorus recycling rates were 73% in AP, 29% in FP, 21% in HC and ~ 0% in NF. The phosphorus use efficiencies showed that, relative to sector input, about 70% was taken up by crops (CP), 24% was retained in animals (AP), 52% was contained in food products (FP), 76% was stored in non-food materials (NF), and 21% was recycled (HC).

Although wide-ranging variation between countries, generally phosphorus use in EU-27 was characterized by relatively (1) large dependency on (primary) imports, (2) long-term accumulation in agricultural soils, especially in west European countries, (3) leaky losses throughout entire society, especially emissions to the environment and sequestered waste, (4) little recycling with the exception of manure, and (5) low use efficiencies, because of aforementioned issues, providing ample opportunities for improvement.
Keywords: Phosphorus cycle; Agricultural balance; Food system; EU-27; Europe; Resource management; Nutrient use efficiency; Substance flow analyses

Jiechen Wu, Daniel Franzén, Maria E. Malmström, Anthropogenic phosphorus flows under different scenarios for the city of Stockholm, Sweden, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1094-1105, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.09.024.
(www.sciencedirect.com/science/article/pii/S0048969715306847)
Abstract
Today, concerns prevail about the unsustainable use of phosphorus and worldwide eutrophication, thus requiring efficient management of phosphorus flows. With increasing population and associated urban growth, urban management of phosphorus flows in the perspectives of recycling, eutrophication and total budget becomes increasingly important. This study mapped phosphorus flows for a reference year (2013) and a future year (2030) using different scenarios for the city of Stockholm, Sweden. The results indicated that the Swedish goal of recycling phosphorus from wastewater would cover the majority of the total phosphorus budget for Stockholm. However, in 2013, only 10% of phosphorus was recycled for agricultural use, around half of which was from sewage sludge and the other half from food waste. Almost 50% of total phosphorus was sent to landfill/mining waste capping with sewage sludge, for economic reasons and lack of market. Among the scenarios of upstream and downstream urban management options studied in combination with population growth, recovery of phosphorus from sewage sludge had the greatest potential to increase the fraction recycled to agriculture. However, only upstream measures, e.g. changed diet, were able to reduce the total phosphorus budget. Urban management of phosphorus flows based on the different perspectives of recycling, eutrophication or total budget was shown to potentially result in different preferred management actions and both upstream and downstream measures need to be considered. Moreover, management needs to pay attention to small but environmentally sensitive flows, particularly when setting city goals on phosphorus recycling by percentage in a large budget.
Keywords: Phosphorus flow analysis; Scenarios; Phosphorus recycling; Total budget; Eutrophication

Bussarakam Thitanuwat, Chongchin Polprasert, Andrew J. Englande Jr., Quantification of phosphorus flows throughout the consumption system of Bangkok Metropolis, Thailand, Science of The Total Environment, Volume 542, Part B, 15 January 2016, Pages 1106-1116, ISSN 0048-9697, dx.doi.org/10.1016/j.scitotenv.2015.09.065.
(www.sciencedirect.com/science/article/pii/S0048969715307257)
Abstract
Due to unequal distribution of the world's Phosphorus (P) sources for fertilizer production, an evaluation of P flows throughout the consumption system of a city is needed. The prime objective of this paper is to assess and prioritize P recovery options as to bring about, as much as possible, a close-looped P-for-food system. Using the Bangkok Metropolitan Administration (BMA) as a case study, the aim of this work is to quantify the potential mass flow of P for four major types of urban wastes: domestic wastewater (DWW), septage sludge (SS), food waste (FW) and green garbage (GB) and to determine the recoverable stock of P available. The consumption of food and supplements such as cleansing products and fertilizer is estimated at a rate of 1146.4 g P·cap− 1·year− 1. P contained in wastes being discarded from its average 7.9 million population plus 33.8 million Bangkok-visiting tourists per annum is determined to be 8.01 kt P annually. Only 4% of the above quantity is recycled and used internally for cultivating plants grown in public parks. An annual amount of 7.68 kt P was found to be disposed of in landfills (6.23 kt P) and in the river systems (1.45 kt P). From the findings of this study, therefore, it is recommended that P recovery efforts from BMA's urban wastes should be focused on wastes enrouted to landfills since these constitute 81% of P discarded. As a consequence, solid waste combustion coupled with energy recovery from P-binding organics may be an appropriate means of P recovery. This technology has the potential to reduce waste volume, generate electricity, and produce P-containing ash that can be used for further application on farm lands.
Keywords: Food consumption; Human excreta; Landfill; Phosphorus recovery; Urban wastes; Wastewater treatment

Thanks for this information, Arno.

About the three books that you mentioned, would you say that any of them is better than any of the 3 documents which I had proposed as "key documents" for newcomers? Should they replace any of them or are they in addition? If the latter, then which two out of the three should I add to the list of 5 (as I don't want to go beyond 5)?

I hesitate a bit to add these books to the list as all three are not freely accessible but behind a paywall. This makes it less useful for newcomers who may not be happy to have to spend e.g. 115 USD for the first book that you mentioned. - Do any of the three books make any links with sanitation?

For the four website links that you listed, I have added them to the list of links. If in doubt, we could also add the three books to the list of links, rather than to the list of 5 key documents for newcomers. - What would you prefer?

And could you tell us more about this new Google group "sustainable phosophorus platform" that you mentioned in the 4th place (perhaps in a new thread, rather)? I have never used Google groups before, are you finding it a convenient tool? How does it compare to LinkedIn groups, for example?

Regards,
Elisabeth

Can add a few more publications:

Karl A. Wyant, Jessica E. Corman, and Jim J. Elser. 2013. Phosphorus Food and Our Future. OUP. 256p. global.oup.com/academic/product/phosphor...16832?cc=us&lang=en&

Butusov, M. and Jernelöv, A. 2013. Phosphorus - An Element that could have been called Lucifer. Springer. www.springer.com/us/book/9781461468028

Special issue of the Springer Journal Nutrient Cycling in Agroecosystems on “Sustainable Phosphorus” 2015. Based on papers given at the Sustainable Phosphorus Summit in 2014 in Montpellier. www.springer.com/life+sciences/agricultu...=0-10028-6-1485341-0

And a few important website resources:

www.phosphorusplatform.eu/
sustainablep.asu.edu/
phosphorusfutures.net/
groups.google.com/d/forum/sustainablephosphorusplatform

For more information about why I am creating this new thread, please see here:
forum.susana.org/forum/categories/10-gen...d-sub-category-level

++++++++++++++

This thread is a "sticky thread" which means it will always remain at the top of this sub-category.
It contains a recommendation for new people regarding the most important 3-5 documents in the thematic area of "phosphorus, the finite resource".

The initial selection was done by me, but this is open for discussion and can be adjusted regularly.

Recommended top three documents in the thematic area of "phosphorus, the finite resource":

(1)
Soil Association (2010). A rock and a hard place - Peak phosphorus and the threat to our food security. Soil Association, UK
www.susana.org/en/resources/library/details/1143

The approaching ‘perfect storm’ of climate change, resource depletion, diet-related ill health and population growth is forcing us all to think again about how we produce and consume food. Yet, there is one critical issue in securing our future food security that is missing from the global policy agenda: we are facing the end of cheap and readily-available phosphate fertiliser on which intensive agriculture is totally dependent. The supply of phosphorus from mined phosphate rock could ‘peak’ as soon as 2033, after which this non-renewable resource will become increasingly scarce and expensive. This report sets out the actions we need to take to close the loop on the phosphorus cycle to address future shortages and prevent further environmental damage from phosphate pollution.

(2)
Schröder, J., Cordell, D., Smit, A., Rosemarin, A. (2010). Sustainable use of phosphorus. Plant Research International, Wageningen, The Netherlands
www.susana.org/en/resources/library/details/1587

Phosphorus is essential for food production, however its use is not without implications. Attention to sustainable phosphorus use is no longer solely focused on reducing detrimental environmental impacts, but also explicitly linked to food security. That is, sustainable phosphorus use must ensure that all the world's farmers have sufficient access to phosphorus in the long run to produce enough food humanity, whilst minmizing adverse environmental and social impacts.

(3)
Rosemarin, A. (2010). Peak Phosphorus, The Next Inconvenient Truth? - 2nd International Lecture Series on Sustainable Sanitation, World Bank, Manila, October 15, 2010
www.susana.org/en/resources/library/details/819

Phosphorus, as a fertiliser, is important for the world's food production. The estimated lifetime of the reserves are ending in approx. 100 years. The demand for phosphorus is rising as well as the prices of this limited resource. The presentation gives an overview of alternative sanitation solutions such as urine diverting toilets, biogas or constructed wetlands to face the agriculture and sanitation challenges.

You can find further important documents and website links dealing with this topic here:

• We invite you to browse the SuSanA library by using the search term "phosphorus":
  www.susana.org/en/resources/library?search=phosphorus
• Information, references and further links about "peak phosphorus" and sanitation on the SSWM website: www.sswm.info/category/background/backgr...sues/peak-phosphorus
• European Sustainable Phosphorus Platform: www.phosphorusplatform.eu/
• Sustainable Phosphorus Initiative (USA): sustainablep.asu.edu/
• Phosphorus Futures - an initiative of the global phosphorus research initiative (Australia): phosphorusfutures.net/
• Sustainable Phosphorus Platform Google Discussion group: groups.google.com/forum/#!forum/sustainablephosphorusplatform - About the discussion group: Phosphorus sustainability - use, impacts, resources, recycling, agriculture, diet, industry, chemistry, soil, water. Initiator: European Sustainable Phosphorus Platform, managed by Arno Rosemarin/SEI. With the North American Partnership for Phosphorus Sustainability & Global Phosphorus Research Initiative
• The following Wikipedia articles exist on this topic:

• Planetary boundaries: en.wikipedia.org/wiki/Planetary_boundaries
• Peak phosphorus: en.wikipedia.org/wiki/Peak_phosphorus

Please provide your feedback. What do you think of this selection? We can update it from time to time.

Regards,
Elisabeth