Implementing carbon tariffs : a fool's errand ?

Some governments are considering taxes on imports based on carbon content from countries that have not introduced climate change policies. Such carbon border taxes appeal to domestic industries facing higher charges for their own carbon emissions. This research demonstrates that there are enormous practical difficulties surrounding such plans. Various policies are evaluated according to World Trade Organization compliance, administrative plausibility, help in meeting environmental goals, and ability to deal with domestic pressures. The steel industry is used as a case study in this analysis. All considered policies arguably fail to meet at least one of these constraints, bringing into question the plausibility that a carbon border tax can be practical policy.Climate Change Mitigation and Green House Gases,Climate Change Economics,Carbon Policy and Trading,Environment and Energy Efficiency,Energy and Environment

A primer on noise-induced transitions in applied dynamical systems

Noise plays a fundamental role in a wide variety of physical and biological dynamical systems. It can arise from an external forcing or due to random dynamics internal to the system. It is well established that even weak noise can result in large behavioral changes such as transitions between or escapes from quasi-stable states. These transitions can correspond to critical events such as failures or extinctions that make them essential phenomena to understand and quantify, despite the fact that their occurrence is rare. This article will provide an overview of the theory underlying the dynamics of rare events for stochastic models along with some example applications

Pacific herring, Clupea pallasi, studies and fishery management in Tomales Bay 1992-93, with notes on Humboldt Bay and Crescent City area landings

The 1992-93 spawning biomass estimate for Pacific herring, Clupea pallasi, in Tomales Bay increased for the fourth year in a row to 4,078 tons. This is the highest estimate since the 1986-87 season. The December spawning biomass total of 1,346 tons was the second highest December escapement total since surveys began in 1972-73. A total of 3.58 million m2 of eelgrass, Zostera marina, was measured in Tomales Bay this season. Eelgrass density increased in the majority of beds. The commercial catch of 222 tons was taken entirely from Tomales Bay since outer Bodega Bay was closed to herring fishing during the season. Gill net mesh size was increased to 2.125 inches from 2.0 inches this season. Herring aged 4,5, and 6 comprised 92% by number of the season's herring catch. Mean weight of herring for each age decreased while mean length for all ages combined increased slightly. Tomales Bay herring samples indicated that older year-classes, missing in commercial catch samples, were present prior to the January start of the commercial fishery. The abundance of 4-yr-old herring was low in samples from variable-mesh and commercial gill nets, indicating less than average recruitment of the 1989 year-class. In Humboldt Bay the 1992-93 season commercial herring catch totalled 28.6 tons, less than half of the 60-ton quota. Crescent City area herring fishermen nearly caught their 30-ton quota with a total of 28.5 tons landed. No spawning biomass estimate is available for the 1992-93 season for either area. (29pp.

Calculation of accurate permanent dipole moments of the lowest 1,3Σ+^{1,3} \Sigma^+ states of heteronuclear alkali dimers using extended basis sets

The obtention of ultracold samples of dipolar molecules is a current challenge which requires an accurate knowledge of their electronic properties to guide the ongoing experiments. In this paper, we systematically investigate the ground state and the lowest triplet state of mixed alkali dimers (involving Li, Na, K, Rb, Cs) using a standard quantum chemistry approach based on pseudopotentials for atomic core representation, gaussian basis sets, and effective terms for core polarization effects. We emphasize on the convergence of the results for permanent dipole moments regarding the size of the gaussian basis set, and we discuss their predicted accuracy by comparing to other theoretical calculations or available experimental values. We also revisit the difficulty to compare computed potential curves among published papers, due to the differences in the modelization of core-core interaction.Comment: accepted to J. Chem. Phy

Pacific herring, Clupea harengus pallasi, studies in San Francisco and Tomales Bays, April 1987 to March 1988

Herring schools were surveyed hydroacoustically and sampled in San Francisco Bay from late October 1987 to March 1988. Nine large schools (greater than 1000 tons) and four smaller ones were detected. Total acoustic biomass estimate, using a combination of echo integration and "visual integration" methods, was 71,110 tons. Improved acoustic calibration parameters resulted in this estimate being close to the spawn escapement-plus-catch estimate of 68,881 tons. However, the two biomass survey methods ere complementary and, when used together, provide a more accurate estimate of the spawning population than either method alone. Eighty-two samples, containing a total of 16,316 herring, were collected with variable-mesh gill net, midwater trawl, or obtained from the roundhaul fishery. Mean body length decreased by more then 20 mm from the beginning to the end of the spawning season. Sex ratios favored males in November and December, while females were more abundant in February and March. The 1982 through 1986 year classes (6- through 2-yr olds) contributed approximately 98% by weight and number to the total 1987-88 spawning biomass in San Francisco Bay. Herring year classes aged 7 and older each comprised no more then 1% of any school. Above average recruitment occurred for the 1986 year class. Recruitment may not be complete for some year classes until age 3 yr. This was particularly evident for the 1985 year clear. (72pp.

Pacific herring, Clupea harengus pallasi, studies in San Francisco Bay, Monterey Bay, and the Gulf of the Farallones, July 1982 to March 1983

Herring stocks were hydroacoustically surveyed and sampled in San Francisco Bay from November 1982 to March 1983. Twelve discrete herring schools were identified, all of which spawned between November 7 and February 23. One additional school was found in the Bay in March but showed no evidence of spawning. Total biomass estimate from hydroacoustic surveys was 67,040 tons. Based on MRR biomass estimates from spawned egg counts, an additional 10,000 tons may have spawned in November and December without being detected hydroacoustically. The largest schools occurred in January and February. Hydroacoustic estimates of biomass for individual schools during the season ranged from 270 to 22,300 tons. Sixty-seven samples, containing a total of 12,232 herring, were collected with variable mesh gill net and midwater trawl or obtained from the commercial roundhaul and gill net fisheries. In general, a trend was observed of decreasing mean size and age as the season progressed. Schools spawning in November and December consisted primarily of 4-, 5-, 6-, and 7-yr-old fish. Schools sampled from January to March were predominantly 2-, 3-, 4-, and 5-yr-old herring. The 1978, 1979, and 1980 yr classes (ages 5, 4, and 3 yr) were strong, comprising up to 90% of the samples. The 1981 yr class (2-yr olds) was relatively weak. Abundant rainfall and resultant low salinity in San Francisco Bay surface waters apparently delayed or prevented herring from spawning in February and March. A relationship may exist between relative abundance of young-of-the-year fish, as noted from midwater trawl samples collected by the Department's Bay-Delta Study, and the resultant year class strength of newly recruited 2-yr-old herring in San Francisco Bay's spawning stocks. (57pp.

Pacific herring, Clupea harengus pallasi, studies in San Francisco Bay, April 1986 to March 1987

Herring schools were surveyed hydroacoustically and sampled in San Francisco Bay from late October 1986 to March 1987. Eight large schools (greater than 1000 tons each) spawned from December to February and seven smaller schools were detected throughout the spawning season. Total acoustic biomass estimate using a "visual integration" technique was 40,930 tons, and it was determined from spawn escapement and commercial landings that an additional 2240 tons were not detected. This is a slight increase from last season's total of approximately 42,200 tons. For the first time, biomass was also estimated using echo integration equipment. A total biomass was obtained of 33,050 tons, including herring not detected acoustically. This estimate must be considered preliminary and subject to revision after target strength of San Francisco Bay herring is determined. Eighty-seven samples, containing a total of 13,125 herring, were collected with variable-mesh gill net and midwater trawl or obtained from the roundhaul and gill net fisheries. Mean body length (BL) of sampled herring decreased by about 20 mm from the beginning to the end of the spawning season. A combination of variable-mesh gill net and midwater trawl samples for a particular school closely approximates mean BL and age composition data from unbiased roundhaul samples. Age-weight and age-length relationships were average to above average compared with those of the previous two seasons. The 1982 year class exhibited unusually good growth, with a mean BL of 202.8 mm for herring aged from stratified random samples. The 1982 through 1985 year classes (5- through 2-yr olds) contributed 97% by number and 95% by weight to the total 1986-87 spawning biomass in San Francisco Bay. Good recruitment has occurred during the past four seasons. The weak 1981 year class contributed little to the total biomass as 6-yr olds. Average catch per tow of young-of-the-year (YOY) herring is a potential index of abundance for recruitment 18 months later as 2-yr olds. Estimated recruitment has only varied by 15% during the past three seasons and does not reflect the magnitude or trend in YOY catches in the bay. (85pp.