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Sustainability Videos & Lecture Series

Q&A with Dr. Elser and Dr. Childers

Sustainable Phosphorus Summit

Transcript

Jessica Corman: [Music 00:00 – 00:26] Welcome to the 2011 Frontiers in Life Sciences Sustainable Phosphorus Summit. We’re gathered here for this weekend to define the scale and the scope of phosphorus sustainability, discuss potential strategies for coming up with a sustainable phosphorus solution and raise awareness both locally and globally.

Phosphorus is essential to all life. It’s found in our bones, our cells, our DNA. Without it we would not be able to survive. And with it we can grow crops to feed the world, but the source of that phosphorus to fertilize is becoming scarce and there’s concerns that we won’t have enough to feed a growing population. However, we waste a lot of phosphorus too. This phosphorus ends up in out waterways, coastal areas, causing eutrophication, fish kills and degrading our environmental resources. Perhaps we can come up with ways to divert this loss of phosphorus and put that back into our field closing the loop and making phosphorus use more sustainable.

While developed countries are currently able to meet their phosphorus demand, many developing countries are not. They are not able to afford or access the fertilizers they need to grow crops. This has led to rampant malnourishment in some of these regions, a situation that will need to be considered when thinking about sustainable phosphorus issues.

I’d like to introduce now two scientists that have been working at the forefront of the sustainable phosphorus issue here at Arizona State University. They are Dr. Jim Elser and Dan Childers. Dr. Elser got involved with the sustainable phosphorus issue through his work with aquatic organisms in lakes. Dr. Childers got involved with it through his work on the ecological implications of phosphorus in wetland systems.

Dr. James Elser: Well, I’ve been working on phosphorus and its role in the environment and ecology and evolution for a long time. We know phosphorus is a pollutant from how it makes lakes get green or overgreen. It wasn’t until a read a paper by Dana Cordell and Stewart White and some other researchers that the issue of phosphorus limitation of human society itself because of its importance in agriculture sort of came to me as a revelation of some kind.

Dr. Dan Childers: Before coming to ASU, I’ve been at ASU about two and a half years, I spent almost 15 years working in the Florida Everglades. The Florida Everglades is a massive wetland system that is very nutrient poor, what we call oligotrophic, and the limiting nutrient in the everglades is phosphorus. We deal with phosphorus concentrations in the everglades on the order of five to ten parts per billion, absolutely miniscule amounts of phosphorus.

One of the biggest problems with the everglades is pollution from urban areas to the east of the everglades where people live and from agricultural areas to the north of the everglades. The pollution coming into the everglades has excess phosphorus in it. For a long time I thought, well, it’s amazing that there’s this natural system that is able to function on very, very low levels of phosphorus at the same time the human systems next door are so leaky and wasteful of it that extra phosphorus is coming into the everglades from those human systems.

Elser: Biggest one right now that we’re involved in involves work on the role of phosphorus and ecology and evolution in some desert springs in Mexico, a place called Cuatro Ciénegas, where phosphorus limitation is severe for all kinds of organisms. We think we can investigate and understand the ways that microorganisms deal with phosphorus limitation. We can start to discover genes and genetic strategies and biological strategies that living things have used to solve phosphorus scarcity issues. Hopefully those will be useful to us going forward as we approach phosphorus limitation ourselves.

Childers: Since coming to ASU, I have become very involved in the central Arizona, Phoenix long-term ecological research project. In particular, my lab group is very involved in understanding and quantifying the effects of rain when it falls on a desert city. It effectively is a storm water project, so what we’re doing is we’re looking at the dynamics of how water moves through a desert city after it falls from the sky, and in particular the transformations of various compounds in that water as it moves through the city, phosphorus being one of those important compounds. A lot of the freshwater systems in Phoenix, and we have a surprising number of them, are phosphorus limited, and so phosphorus supply from storm water runoff is an important aspect of understanding the urban ecology of an arid land city.

Elser: Well, we’re trying to mobilize scientists and policymakers to get more serious about getting better information about where phosphorus is distributed, how it moves around in the system so that we could begin to identify the places where there’s big inefficiencies in phosphorus use in our human system so we can be able to tighten those up so we can really achieve long-term sustainable agricultural systems.

Childers: One of the big reasons for having the international Sustainable Phosphorus Summit is to directly inform policymakers both in industry and in government. One of the advantages I think we faced with the phosphorus challenge is that I see it as being a challenge where we have enough time before any real crisis hits that we can actually potentially begin to solve the problem before it becomes a critical crisis.

Elser: Ultimately the most important human activity that we have is to grow our food and to feed ourselves. I think that achieving a truly sustainable agricultural system affects all aspects of human society and it’s the one that needs the greatest amount of attention.

Childers: The sustainability challenge that probably concerns me the most is what I teach my students in the school of sustainability is the common denominator to all sustainability challenges and that is human population growth. Our population has grown by 50 percent in the last 50 years. Thanks to the green revolution and to phosphorus fertilizers, we’re projected to grow by another 3 billion by 2050. Fundamentally that is the real challenge that we’re facing. The sustainable phosphorus issue fits into that greater human population challenge because people need food and because phosphorus is a non-substitutable, irreplaceable element. It’s an absolute necessity for us producing the food that we need, and without it, we simply can’t eat. [Music 07:07 – 07:21]

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