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).
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. "
EAT THE LIGHT: The Fourth Age of Solar
by Geoff Olson
by Patrick Déry and Bart Anderson
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.
In this paper, Patrick Déry applies Hubbert's methods to a very special non-renewable resource - phosphorus - a nutrient essential for agriculture.
The United States, a major phosphate producer.
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.
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.
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).
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).
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.