Monday, January 25, 2010

NF3, Solar Panels, Unintended Consequences

As with lots of issues tied to climate change, global ecosystems, energy, climate disruption, this story has been reported several times, but here's the Scripps' version. Of course, elements used in solar panels are going to reach global peak in 30 to 50 years, by some estimates. And what about phosphorus ? Read below this article. More on peak copper, lithium, gallium, iridium, water.

Potent Greenhouse Gas More Prevalent in Atmosphere than Previously Assumed

Compound used in manufacture of flat panel televisions, computer displays, microcircuits, solar panels is 17,000 times more potent greenhouse gas than carbon dioxide

Scripps Institution of Oceanography / University of California, San DiegoA powerful greenhouse gas is at least four times more prevalent in the atmosphere than previously estimated, according to a team of researchers at Scripps Institution of Oceanography at UC San Diego. Using new analytical techniques, a team led by Scripps geochemistry professor Ray Weiss made the first atmospheric measurements of nitrogen trifluoride (NF3), which is thousands of times more effective at warming the atmosphere than an equal mass of carbon dioxide.The amount of the gas in the atmosphere, which could not be detected using previous techniques, had been estimated at less than 1,200 metric tons in 2006. The new research shows the actual amount was 4,200 metric tons. In 2008, about 5,400 metric tons of the gas was in the atmosphere, a quantity that is increasing at about 11 percent per year.

Different generations of collection cylinders used to collect air samples from locations around the world over the past 30 years. Scripps Institution of Oceanography at UC San Diego geochemistry researchers Ray Weiss and Jens Muehle led a study that found that the greenhouse gas nitrogen trifluoride, used in the manufacture of flat-panel monitors, escapes to the atmosphere at levels much higher than previously assumed."Accurately measuring small amounts of NF3 in air has proven to be a very difficult experimental problem, and we are very pleased to have succeeded in this effort," Weiss said. The research will be published Oct. 31 in Geophysical Research Letters, a journal of the American Geophysical Union (AGU).

Emissions of NF3 were thought to be so low that the gas was not considered to be a significant potential contributor to global warming. It was not covered by the Kyoto Protocol, the 1997 agreement to reduce greenhouse gas emissions signed by 182 countries. The gas is 17,000 times more potent as a global warming agent than a similar mass of carbon dioxide. It survives in the atmosphere about five times longer than carbon dioxide. Current NF3 emissions, however, contribute only about 0.04 percent of the total global warming effect contributed by current human-produced carbon dioxide emissions.

Nitrogen trifluoride is one of several gases used during the manufacture of liquid crystal flat-panel displays, thin-film photovoltaic cells and microcircuits. Many industries have used the gas in recent years as an alternative to perfluorocarbons, which are also potent greenhouse gases, because it was believed that no more than 2 percent of the NF3 used in these processes escaped into the atmosphere.The Scripps team analyzed air samples gathered over the past 30 years, working under the auspices of the NASA-funded Advanced Global Atmospheric Gases Experiment (AGAGE) network of ground-based stations. The network was created in the 1970s in response to international concerns about chemicals depleting the ozone layer.

It is supported by NASA as part of its congressional mandate to monitor ozone-depleting trace gases, many of which are also greenhouse gases. Air samples are collected at several stations around the world. The Scripps team analyzed samples from coastal clean-air stations in California and Tasmania for this research.The researchers found concentrations of the gas rose from about 0.02 parts per trillion in 1978 to 0.454 parts per trillion in 2008.

The samples also showed significantly higher concentrations of NF3 in the Northern Hemisphere than in the Southern Hemisphere, which the researchers said is consistent with its use predominantly in Northern Hemisphere countries. The current observed rate of increase of NF3 in the atmosphere corresponds to emissions of about 16 percent of the amount of the gas produced globally.

Scripps geoscientists Ray Weiss (green shirt) and Jens Muehle amid collection cylinders used to collect air samples from a variety of locations around the world. Weiss and Muehle led a study that found that the greenhouse gas nitrogen trifluoride, used in the manufacture of flat-panel monitors, escapes to the atmosphere at levels much higher than previously assumed.In response to the growing use of the gas and concerns that its emissions are not well known, scientists have recently recommended adding it to the list of greenhouse gases regulated by Kyoto. "

As is often the case in studying atmospheric emissions, this study shows a significant disagreement between 'bottom-up' emissions estimates and the actual emissions as determined by measuring their accumulation in the atmosphere," Weiss said. "From a climate perspective, there is a need to add NF3 to the suite of greenhouse gases whose production is inventoried and whose emissions are regulated under the Kyoto Protocol, thus providing meaningful incentives for its wise use."

"This result reinforces the critical importance of basic research in determining the overall impact of the information technology industry on global climate change, which has already been estimated to be equal to that of the aviation industry," added Larry Smarr, director of the California Institute for Telecommunications at UCSD, who was not involved in the Scripps study.Michael Prather is a UC Irvine atmospheric chemist who predicted earlier this year that based on the rapidly increasing use of NF3, larger amounts of the gas would be found in the atmosphere. Prather said the new Scripps study provides the confirmation needed to establish reporting requirements for production and use of the gas."I'd say case closed. It is now shown to be an important greenhouse gas," said Prather, who was not involved with the Scripps study.

"Now we need to get hard numbers on how much is flowing through the system, from production to disposal."Co-authors of the paper are Scripps researchers Jens Mühle, Peter Salameh and Christina Harth.

Notes for Journalists

As of the date of this press release, this study by Weiss and his colleagues is still "in press" (i.e. not yet published). Journalists and public information officers of educational and scientific institutions who have registered with AGU can download a PDF copy of a manuscript of this paper by clicking on this link:

Beginning Oct. 31, registered news media and PIOs may directly download the final, copy-edited and formatted PDF of the paper by clicking on the following link:

Or, you may order a copy of the paper by emailing your request to Peter Weiss at, Maria-José Viñas at, Robert Monroe or Mario Aguilera at, or to Steve Cole at

Please provide your name, the name of your publication, and your phone number.
Just in time for "peak everything"...
04/09/08 08:57
EAT THE LIGHT: The Fourth Age of Solar
by Geoff Olson

Peak phosphorus

by Patrick Déry and Bart Anderson

Peak oil has made us aware that many of the resources on which civilization depends are limited.
M. King Hubbert, a geophysicist for Shell Oil, found that oil production over time followed a curve that was roughly bell-shaped. He correctly predicted that oil production in the lower 48 states would peak in 1970. Other analysts following Hubbert's methods are predicting a peak in oil production early this century.

The depletion analysis pioneered by Hubbert can be applied to other non-renewable resources. Analysts have looked at peak production for resouces such as natural gas, coal and uranium.
In this paper, Patrick Déry applies Hubbert's methods to a very special non-renewable resource - phosphorus - a nutrient essential for agriculture.

In the literature, estimates before we "run out" of phosphorus range from 50 to 130 years. This date is conveniently far enough in the future so that immediate action does not seem necessary. However, as we know from peak oil analysis, trouble begins not when we "run out" of a resource, but when production peaks. From that point onward, the resource becomes more difficult to extract and more expensive.

Physicist Déry applied the technique of Hubbert Linearization to data available from the United States Geological Survey (USGS)[1] to phosphorus production in the following:

The small Pacific island nation of Nauru, a former phosphate exporter.
The United States, a major phosphate producer.
The world.

He tested Hubbert Linearization first on data from Nauru to see whether he could have predicted the year of its peak phosphate production in 1973. Satisfied with the results, he applied the method to United States and the world. He estimates that U.S. peak phosphorus occurred in 1988 and for the world in 1989.

Phosphorus - its role and nature

Phosphorus (chemical symbol P) is an element necessary for life. Because phosphorus is highly reactive, it does not naturally occur as a free element, but is instead bound up in phosphates. Phosphates typically occur in inorganic rocks.

As farmers and gardeners know, phosphorus is one of the three major nutrients required for plant growth: nitrogen (N), phosphorus (P) and potassium (K). Fertilizers are labelled for the amount of N-P-K they contain (for example 10-10-10).

Most phosphorus is obtained from mining phosphate rock. Crude phosphate is now used in organic farming, whereas chemically treated forms such as superphosphate, triple superphosphate, or ammonium phosphates are used in non-organic farming.
Philip H. Abelson writes in Science:

The current major use of phosphate is in fertilizers. Growing crops remove it and other nutrients from the soil... Most of the world's farms do not have or do not receive adequate amounts of phosphate. Feeding the world's increasing population will accelerate the rate of depletion of phosphate reserves.


...resources are limited, and phosphate is being dissipated. Future generations ultimately will face problems in obtaining enough to exist.

It is sobering to note that phosphorus is often a limiting nutrient in natural ecosystems. That is, the supply of available phosphorus limits the size of the population possible in those ecosystems.
More information:

Understanding Phosphorus and its Use in Agriculture from the European Fertilizer Manufacturers Association.

Phosphate Primer by Florida Institute of Phosphate Research.

Prospect of a Phosphorus Peak

In his frightening book Eating Fossil Fuels [3], Dale Allen Pfeiffer shows that conventional agriculture is as oil-addicted as the rest of society. A decline in oil production raises questions about how we will feed ourselves.

In the same way, agriculture is addicted to mined phosphates and would be threatened by a peak in phosphate production. As the U.S. Geological Survey (USGS) wrote in summary on phosphates (PDF):

There are no substitutes for phosphorus in agriculture.
Fortunately, phosphorus - unlike oil - can be recycled. Responses to a phosphorus peak include re-creating a cycle of nutrients, for example, returning animal (including human) manure to cultivated soil as Asian people have done in the not-so-distant past [4].

Hubbert Linearization

Tools that have been used for analyzing peak oil can be applied to phosphate production. As we will see, phosphorus production follows a more-or-less bell-shaped (parabolic) curve, just as oil production does.

Hubbert's parabolic curve is based on a differential equation explained by Stuart Staniford:
The idea behind the equation is that early on, the oil industry grows exponentially - the annual increase in production is proportional to the total amount of knowledge of resources, oil field equipment, and skilled personnel, all of which are proportional to the size of the industry. ...
Later, however, the system begins to run into the finiteness of the resource - it gets harder and harder to get the last oil from the bottom of the depressurized fields, two miles down in the ocean, etc, etc.

To estimate future production and total production, some analysists have turned to the technique of Hubbert Linearization (H-L).

Hubbert Linearization was first developed by geologist Kenneth Deffeyes, an associate of M. King Hubbert. The technique has been discussed by analysts such as Stuart Staniford, Jeffrey J. Brown and Robert Rapier at The Oil Drum. The term Hubbert Linearization was coined by Stuart Staniford.

In Hubert Linearization, the production data from the bell-shaped Hubbert curve is plotted as a line. On the graph:

the y-axis (vertical) is P/Q whereP = annual production andQ = total production to date
the x-axis (horizontal) is Q (total production to date).

By extending the line in the graph, one can estimate Ultimate Recoverable Reserves (URR) for the region (Qt).

This paper purposely minimizes the math so as to reach a wide audience; however, much more detail on H-L is available online. For example:

Applying Hubbert Linearization to Phosphates

For the purposes of this paper, Déry looked at data for commercial phosphate (26-34% of P2O5). Other reserves of rock phosphate with lower concentrations of P2O5 do exist, but, just as with tar sand for oil production, they are more costly to exploit - economically, energetically and environmentally.

Using data from United States Geological Survey (rock phosphate production historical data series), Déry did a Hubbert Linearization for United States and for world rock phosphate production.

Results were stunning. The theoretical logistic curve fits almost perfectly with the real data curve. Déry found that we have already passed the phosphate peak for the United States (1988) and for the world (1989).


However those results seemed too perfect, so Déry tested the method on an almost depleted region of rock phosphate production, a case similar to that of United Stated for oil. A small island in the South Pacific called Nauru appeared to be an ideal case. The Nauru Island is 21 km² with only one economic resource (besides being a fiscal paradise!): rock phosphate. This resource has been almost entirely depleted since 2005.

According to the CIA World Factbook:

...intensive phosphate mining during the past 90 years - mainly by a UK, Australia, and NZ consortium - has left the central 90% of Nauru a wasteland and threatens limited remaining land resources

Plotting the rise and fall of rock phosphate production on Nauru yields this graph (see above):

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