Issues in Energy Economics Led by Emerging Linkages between the Natural Gas and Power Sectors

Fuel prices in 2006 continued at record levels, with uranium continuing upward unabated and coal, SO₂ emission allowances, and natural gas all softening. This softening did not continue for natural gas, however, whose prices rose, fell and rose again, first following weather influences and, by the second quarter of 2007, continuing at high levels without any support from fundamentals. This article reviews these trends and describes the remarkable increases in fuel expenses for power generation. By the end of 2005, natural gas claimed 55% of annual power sector fuel expenses, even though it was used for only 19% of electric generation. Although natural gas is enormously important to the power sector, the sector also is an important driver of the natural gas market—growing to over 28% of the market even as total use has declined. The article proceeds to discuss globalization, natural gas price risk, and technology developments. Forces of globalization are poised to affect the energy markets in new ways—new in not being only about oil. Of particular interest in the growth of intermodal traffic and its a little-understood impacts on rail traffic patterns and transportation costs, and expected rapidly expanding LNG imports toward the end of the decade. Two aspects of natural gas price risk are discussed: how understanding the use of gas in the power sector helps define price ceilings and floors for natural gas, and how the recent increase in the natural gas production after years of record drilling could alter the supply–demand balance for the better. The article cautions, however, that escalation in natural gas finding and development costs is countering the more positive developments that emerged during 2006. Regarding technology, the exploitation of unconventional natural gas was one highlight. So too was the queuing up of coal-fired power plants for the post-2010 period, a phenomenon that has come under great pressure with many consequences including increased pressures in the natural gas market. The most significant illustration of these forces was the early 2007 suspension of development plans by a large power company, well before the Supreme Court’s ruling on CO₂ as a tailpipe pollutant and President Bush’s call for global goals on CO₂ emissions.

A 1500-year record of climatic and environmental change in ElkLake, Minnesota III: measures of past primary productivity

Diatom analysis of a varved sediment core from Elk Lake, Minnesotadocuments important natural and human-caused shifts in primary productivity atdecadal scales for the past 1500 years. Interpretations from a perspective ofplanktic diatom seasonal dynamics and from total phosphorus inferences based ona 111-lake training set of freshwater Canadian lakes reveal a major change tomore productive environments after 1000 years ago probably caused by earlierice-out and stronger, longer periods of lake circulation during the spring.European impacts in the region, principally logging in the Elk Lake drainage,during the past 100 years increased nutrient fluxes and turbulence during theopen water season to promote blooms of Aulacoseiraambigua. High resolution (semi-decadal) diatom analyses suggestsunspot cycle periodicities that may reflect short-term changes in thecharacter of irradiance and (or) sun-climate interactions. Total epilimneticphosphorus inferences from the Canadian training set applied to the Elk Lakediatom record document both long-term and short-term variations inproductivity and reconstruct past phosphorus values consistent with somepresent-day measured values at Elk Lake. The Elk Lake study underscores theneed for neolimnological monitoring of both training set and target lakes aswell as for the application of a multiple proxy protocol to documentpaleo-productivity that approaches neolimnological resolution.     

Tracking abrupt climate change in the Southern Hemisphere: a seismic stratigraphic study of Lago Cardiel, Argentina (49°S)

Lake sediments from a closed basin in southern Patagonia (Argentina) provide a continental archive with which to reconstruct climate change and to test the interhemispheric synchroneity of abrupt events. High-resolution sub-bottom seismic profiles of Lago Cardiel indicate substantial lake-level changes since the late Pleistocene, which were identified and dated in a series of long piston cores. These data allow the reconstruction of the regional water balance at 49=" PSFT − BC "202S since the late glacial. The seismic stratigraphy reveals a dry late glacial climate with a desiccation of the basin around 11 220 yr BP (¹⁴C). Lake level rapidly increased by 135 m at the Holocene transition. Following the early Holocene highstand at + 55 m, lake level never dropped significantly below modern level. The palaeoclimate changes implied by the Lago Cardiel record are out-of-phase with those implied by records from tropical South America and demonstrate considerable latitudinal asynchroneity in the climate evolution of this continent.     

Heterogeneous and Homogeneous Chemistry of Reactive Halogen Compounds in the Lower Troposphere

This issue of the Journal of Atmospheric Chemistry contains a series of contributions describing recent developments in our understanding of the heterogeneous and homogeneous chemistry of reactive halogen compounds in the lower Troposphere. Twelve papers describe recent results in this very active area of research, were reported at the Annual Assembly of the European Geophysical Society 1998 in Nice, France, 20-24 April 1998. Considerable progress is documented on the elucidation of the various processes involved in the sources, transformation pathways and chemical consequences of the Reactive Halogen Species (RHS) in the troposphere.     

Nepheline-bearing rocks from the Poohbah Lake complex,Ontario: Malignites and Malignites

Malignites from the Poohbah Lake complex of northwestern Ontario, Canada are melanocratic cumulates. Cumulus pyroxene and apatite are poikilitically enclosed in a groundmass of large plates of intercumulus orthoclase and nepheline. Nepheline-feldspar fingerprint-like intergrowths occur. Nephelines are commonly zeolitized and pyroxenes altered to aggregates of biotite and/or garnet by deuteric alteration. Pyroxenes are weakly zoned from Di₇₁ Hd¹⁸Ac₁₁ to Di₆₃Hd₂₂Ac₁₅, and are similar to the least evolved pyroxenes of other alkaline rocks. Nephelines all have compositions within the Morozewicz-Buerger convergence field and feldspars have a limited compositional range from Or⁸⁸ to Or⁹⁵. Perthites are absent.Inconsistancies in the usage of the terms malignite and juvite are discussed and it is considered that a non-genetic petrographic classification of nepheline syenites leads to the obscuration of a group of potassic nepheline syenites, characterized by the presence of nepheline plus orthoclase which are typically associated with saturated to over-saturated alkaline rocks, contain pseudo-leucite or nepheline-orthoclase intergrowths, are emplaced in mobile belts and are not associated with rocks of the ijolite-carbonatite suite.A genetic classification of nepheline syenites is suggested and it is proposed that; (1) mafic-rich nepheline syenites be referred to as mela-nepheline syenites (sensu lato) rather than as malignites; (2) the term malignite be used for magmatic potassic nepheline syenites characterised by the presence of nepheline plus a single potassium-rich feldspar (orthoclase or microcline) and devoid of exsolution perthite under subsolvus conditions; (3) the metasomatic malignites and juvites of ijolite-carbonatite complexes be referred to as varieties of fenites.     

The interpretation of baseline atmospheric turbidity measurements at Cape Grim,Tasmania

Five years of turbidity data at Cape Grim have been analysed. The turbidity at 500 nm in clean maritime airmasses from the South to the West shows a seasonal variation, with a minimum in winter. There is also a variation in turbidity with wind speed. The winter minimum can be explained partially by a minimum in wind strength in that season. On the assumption, based on observations at Cape Grim and at other locations, that the boundary layer turbidity is caused by seasalt haze, an attempt is made to interpret the observed turbidity values and their seasonal changes. Optical extinction coefficients at the surface deduced from the measured values of optical depth are compared with extinction coefficients calculated from Mie theory using particle size distributions measured at Cape Grim. Reasonable agreement is obtained when the growth of salt particles in the high maritime humidity is considered, using both theoretical models and previous experimental results together with the rapid increase in salt concentration with wind speed.     

THE FARMLAND CONVERSION DEBATE: NALS AND BEYOND*

The need to protect high quality agricultural land through public policies and programs at various levels of government has been debated in the U.S. for at least three decades. This article reviews the evolution of the debate before 1979, the ill-fated attempt of the National Agricultural Lands Study (NALS) (1979–1981) to resolve the debate, and the current status of the land conversion issue. Articulation of the issue has been impeded by confusion of objectives, semantic problems, unreliability of land conversion data, and excess capacity in the American farm economy. Land conversion estimates published in 1977 by the Soil Conservation Service and relied upon by NALS have proven to be misleading in light of the 1982 National Resources Inventory. State and local programs to discourage farmland conversion are justifiable in terms of land use planning objectives, maintenance of a viable local farm economy, and avoidance of undue reliance upon marginal lands requiring costly technical inputs.     

Internal structure of a collapsed terrain: The Lújar syncline and its significance for the fold- and sheet-structure of the Alborán Domain (Betic Cordilleras, Spain)

Detailed structural analysis of the Sierra de Lújar in the western Alpujarras region (Betic Cordilleras, S Spain), a very representative area of the terrain known as the Alborán Domain, has revealed the existence of a very large N-vergent recumbent syncline which involves the whole mountain massif and neighbouring areas. The Lújar syncline and, probably, the associated recumbent anticline which crops out southeast of Sierra de Lújar show a great variation in the orientation of the hinge line. Although having a curved shape, the hinge line is contained in a plane whose attitude coincides with the main attitude of the axial-plane crenulation foliation (Sc), suggesting that it is a sheath fold.The strongly deformed overturned limb of the syncline is cut by two low-angle normal faults displacing towards the north. Similarity in the kinematics between the faults and the fold, and the association between the faults and the high-strain zone in the overturned limb of the fold, suggest that they are related. Regional constraints on the age of the crenulation cleavage and the low-angle normal faults indicate that they formed during the early Miocene late-orogenic extensional event in the Alborán Domain.We propose an alternate explanation for the structure of the Alpujarras region in which the Lújar syncline forms part of a recumbent syncline–anticline pair that extends along much of the Alpujarride outcrop in the southern Betic Cordillera. In several places, the fold is disrupted by low-angle normal faults, and it is overlain by an upper Alpujárride extensional sheet mainly composed of medium- to high-grade metamorphic rocks. We suggest that all these structures arose from the extensional deformation under decreasing temperature conditions of a previously thickened and metamorphosed orogenic crust.     

Crustal development in the Agnew region,Western Australia,as shown by Rb/Sr isotopic and geochemical studies

Rb/Sr geochronology on a folded greenstone-granitoid complex in the Agnew area, Western Australia, yields four distinct ages of igneous activity that conform with stratigraphic and intrusive relationships. They are (using $\text{λ}{}^{87}\text{Rb}\text{= 1.42 · 10}{}^{\mathrm{?11}}\text{a}{}^{\mathrm{?1}}$, NBS 70A = 522 ppm Rb and 65.3 ppm Sr):

     

100.

The History of Recent Limnological Changes and Human Impact on Upper Klamath Lake, Oregon     

J. Platt Bradbury  Steven M. Colman  Richard L. Reynolds 《Journal of Paleolimnology》2004,31(2):151-165

Hypereutrophic Upper Klamath Lake has been studied for almost 50 years to evaluate the nature, cause, and effects of its very productive waters. Mitigation of undesirable effects of massive cyanobacterial blooms requires understanding their modern causes as well as their history. Knowledge of the pre-settlement natural limnology of this system can provide guidelines for lake restoration and management of land and water use strategies to maximize the benefits of this aquatic resource. This investigation uses a paleolimnological approach to document the nature and chronology of limnological and biological changes in Upper Klamath Lake for the past 200 years, covering the time when the lake was first described until today. A 45-cm gravity core, dated by ²¹⁰Pb and diatom correlations, was analyzed for diatoms, pollen, akinetes (resting spores) of the cyanobacterium Aphanizomenon flos-aquae, reworked tephra shards, and sediment magnetic characteristics. Pollen profiles show little vegetation change during this time. In contrast, diatoms indicative of increased nutrient fluxes (P and Si) increase moderately, coinciding with the settlement of the region by Euro-Americans. Numerous settlement activities, including draining of lake-margin marshes, upstream agriculture and timber harvest, road construction, and boat traffic, may have affected the lake. Magnetic properties and reworked tephra suggest riparian changes throughout the basin and increased lithogenic sediment delivery to the lake, especially after 1920 when the marshes near the mouth of the Williamson River were drained and converted to agricultural and pasture land. Drainage and channelization also decreased the ability of the marshes to function as traps and filters for upstream water and sediments. Akinetes of Aphanizomenon flos-aquae record progressive eutrophication of Upper Klamath Lake beginning in the 20th century and particularly after 1920 when lake-margin marsh reclamation more than doubled. The coincidence of limnological changes and human activities following European settlement suggests a major impact on the Upper Klamath Lake ecosystem, although ascribing specific limnological changes to specific human activities is difficult.     

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	Ma	87Sr/86Sr initial (IR)
(1) Differentiated gabbro-granophyre from a stratigraphically old (Kathleen Valley) greenstone sequence	$\text{> 2718 ± 50}$	$\text{0.7007 ± 0.0004}$
(2) Voluminous tonalite, the Lawlers Tonalite	$\text{2652 ± 20}$	$\text{0.70152 ± 0.00012}$
	$\text{2576 ± 14}$	$\text{0.70218 ± 0.00021}$
(3) A less voluminous leucogranite, and a large complex pegmatite cutting the Perseverance nickel orebody	$\text{2588 ± 18}$	$\text{0.7624 ± 0.0068}$
(4) Aplitic leucotonalite (very minor volumes but widespread)	$\text{2474 ± 14}$	$\text{0.70193 ± 0.00012}$

The History of Recent Limnological Changes and Human Impact on Upper Klamath Lake, Oregon

Hypereutrophic Upper Klamath Lake has been studied for almost 50 years to evaluate the nature, cause, and effects of its very productive waters. Mitigation of undesirable effects of massive cyanobacterial blooms requires understanding their modern causes as well as their history. Knowledge of the pre-settlement natural limnology of this system can provide guidelines for lake restoration and management of land and water use strategies to maximize the benefits of this aquatic resource. This investigation uses a paleolimnological approach to document the nature and chronology of limnological and biological changes in Upper Klamath Lake for the past 200 years, covering the time when the lake was first described until today. A 45-cm gravity core, dated by ²¹⁰Pb and diatom correlations, was analyzed for diatoms, pollen, akinetes (resting spores) of the cyanobacterium Aphanizomenon flos-aquae, reworked tephra shards, and sediment magnetic characteristics. Pollen profiles show little vegetation change during this time. In contrast, diatoms indicative of increased nutrient fluxes (P and Si) increase moderately, coinciding with the settlement of the region by Euro-Americans. Numerous settlement activities, including draining of lake-margin marshes, upstream agriculture and timber harvest, road construction, and boat traffic, may have affected the lake. Magnetic properties and reworked tephra suggest riparian changes throughout the basin and increased lithogenic sediment delivery to the lake, especially after 1920 when the marshes near the mouth of the Williamson River were drained and converted to agricultural and pasture land. Drainage and channelization also decreased the ability of the marshes to function as traps and filters for upstream water and sediments. Akinetes of Aphanizomenon flos-aquae record progressive eutrophication of Upper Klamath Lake beginning in the 20th century and particularly after 1920 when lake-margin marsh reclamation more than doubled. The coincidence of limnological changes and human activities following European settlement suggests a major impact on the Upper Klamath Lake ecosystem, although ascribing specific limnological changes to specific human activities is difficult.