scholarly journals Constraining sector-specific CO<sub>2</sub> and CH<sub>4</sub> emissions in the United States

2016 ◽  
Author(s):  
Scot M. Miller ◽  
Anna M. Michalak

Abstract. This review paper explores recent efforts to estimate state- and national-scale carbon dioxide (CO2) and methane (CH4) emissions from individual anthropogenic source sectors in the United States. Nearly all state and national climate change regulations in the US target specific source sectors, and detailed monitoring of individual sectors presents a greater challenge than monitoring total emissions. We particularly focus on opportunities to synthesize disparate types of information on emissions, including emissions inventory data and atmospheric greenhouse gas data. We find that inventory estimates of sector-specific CO2 emissions are sufficiently accurate for policy evaluation at national scale but that uncertainties increase at state and local levels. CH4 emissions inventories are highly uncertain for all source sectors at all spatial scales, in part because of the complex, spatially-variable relationships between economic activity and CH4 emissions. In contrast to inventory estimates, top-down estimates use measurements of atmospheric concentrations to infer emissions at the surface; these efforts have had little success identifying CO2 emissions from anthropogenic sources but have successfully identified sector-specific CH4 emissions in several opportunistic cases. We also describe a number of forward-looking opportunities that would aid efforts to estimate sector-specific emissions: fully combine existing top-down datasets, expand intensive aircraft measurement campaigns and measurements of secondary tracers, and improve the economic and demographic data (e.g., activity data) that drive emissions inventories. These steps would better synthesize inventory and top-down data to support sector-specific emissions reduction policies.

2017 ◽  
Vol 17 (6) ◽  
pp. 3963-3985 ◽  
Author(s):  
Scot M. Miller ◽  
Anna M. Michalak

Abstract. This review paper explores recent efforts to estimate state- and national-scale carbon dioxide (CO2) and methane (CH4) emissions from individual anthropogenic source sectors in the US. Nearly all state and national climate change regulations in the US target specific source sectors, and detailed monitoring of individual sectors presents a greater challenge than monitoring total emissions. We particularly focus on opportunities to synthesize disparate types of information on emissions, including emission inventory data and atmospheric greenhouse gas data.We find that inventory estimates of sector-specific CO2 emissions are sufficiently accurate for policy evaluation at the national scale but that uncertainties increase at state and local levels. CH4 emission inventories are highly uncertain for all source sectors at all spatial scales, in part because of the complex, spatially variable relationships between economic activity and CH4 emissions. In contrast to inventory estimates, top-down estimates use measurements of atmospheric mixing ratios to infer emissions at the surface; thus far, these efforts have had some success identifying urban CO2 emissions and have successfully identified sector-specific CH4 emissions in several opportunistic cases. We also describe a number of forward-looking opportunities that would aid efforts to estimate sector-specific emissions: fully combine existing top-down datasets, expand intensive aircraft measurement campaigns and measurements of secondary tracers, and improve the economic and demographic data (e.g., activity data) that drive emission inventories. These steps would better synthesize inventory and top-down data to support sector-specific emission reduction policies.


Author(s):  
Funda Hatice Sezgin ◽  
Yilmaz Bayar ◽  
Laura Herta ◽  
Marius Dan Gavriletea

This study explores the impact of environmental policies and human development on the CO2 emissions for the period of 1995–2015 in the Group of Seven and BRICS economies in the long run through panel cointegration and causality tests. The causality analysis revealed a bilateral causality between environmental stringency policies and CO2 emissions for Germany, Japan, the United Kingdom, and the United States of America, and a unilateral causality from CO2 emissions to the environmental stringency policies for Canada, China, and France. On the other hand, the analysis showed a bilateral causality between human development and CO2 emissions for Germany, Japan, the United Kingdom, and the United States of America, and unilateral causality from CO2 emissions to human development in Brazil, Canada, China, and France. Furthermore, the cointegration analysis indicated that both environmental stringency policies and human development had a decreasing impact on the CO2 emissions.


2013 ◽  
Vol 13 (4) ◽  
pp. 9849-9893 ◽  
Author(s):  
H. Lei ◽  
X.-Z. Liang ◽  
D. J. Wuebbles ◽  
Z. Tao

Abstract. Atmospheric mercury is a toxic air and water pollutant that is of significant concern because of its effects on human health and ecosystems. A mechanistic representation of the atmospheric mercury cycle is developed for the state-of-the-art global climate-chemistry model, CAM-Chem (Community Atmospheric Model with Chemistry). The model simulates the emission, transport, transformation and deposition of atmospheric mercury (Hg) in three forms: elemental mercury (Hg(0)), reactive mercury (Hg(II)), and particulate mercury (PHg). Emissions of mercury include those from human, land, ocean, biomass burning and volcano related sources. Land emissions are calculated based on surface solar radiation flux and skin temperature. A simplified air–sea mercury exchange scheme is used to calculate emissions from the oceans. The chemistry mechanism includes the oxidation of Hg(0) in gaseous phase by ozone with temperature dependence, OH, H2O2 and chlorine. Aqueous chemistry includes both oxidation and reduction of Hg(0). Transport and deposition of mercury species are calculated through adapting the original formulations in CAM-Chem. The CAM-Chem model with mercury is driven by present meteorology to simulate the present mercury air quality during the 1999–2001 periods. The resulting surface concentrations of total gaseous mercury (TGM) are then compared with the observations from worldwide sites. Simulated wet depositions of mercury over the continental United States are compared to the observations from 26 Mercury Deposition Network stations to test the wet deposition simulations. The evaluations of gaseous concentrations and wet deposition confirm a strong capability for the CAM-Chem mercury mechanism to simulate the atmospheric mercury cycle. The results also indicate that mercury pollution in East Asia and Southern Africa is very significant with TGM concentrations above 3.0 ng m−3. The comparison to wet deposition indicates that wet deposition patterns of mercury are more affected by the spatial variability of precipitation. The sensitivity experiments show that 22% of total mercury deposition and 25% of TGM concentrations in the United States are resulted from domestic anthropogenic sources, but only 9% of total mercury deposition and 7% of TGM concentrations are contributed by transpacific transport. However, the contributions of domestic and transpacific sources on the western United States levels of mercury are of comparable magnitude.


2018 ◽  
Vol 108 (11) ◽  
pp. 1326-1336 ◽  
Author(s):  
Clive H. Bock ◽  
Carolyn A. Young ◽  
Katherine L. Stevenson ◽  
Nikki D. Charlton

Scab (caused by Venturia effusa) is the major disease of pecan in the southeastern United States. There is no information available on the fine-scale population genetic diversity or the occurrence of clonal types at small spatial scales that provides insight into inoculum sources and dispersal mechanisms, and potential opportunity for sexual reproduction. To investigate fine-scale genetic diversity, four trees of cultivar Wichita (populations) were sampled hierarchically: within each tree canopy, four approximately evenly spaced terminals (subpopulations) were selected and up to six leaflets (sub-subpopulations) were sampled from different compound leaves on each terminal. All lesions (n = 1 to 8) on each leaflet were sampled. The isolates were screened against a panel of 29 informative microsatellite markers and the resulting multilocus genotypes (MLG) subject to analysis. Mating type was also determined for each isolate. Of 335 isolates, there were 165 MLG (clonal fraction 49.3%). Nei’s unbiased measure of genetic diversity for the clone-corrected data were moderate to high (0.507). An analysis of molecular variance demonstrated differentiation (P = 0.001) between populations on leaflets within individual terminals and between terminals within trees in the tree canopies, with 93.8% of variance explained among isolates within leaflet populations. Other analyses (minimum-spanning network, Bayesian, and discriminant analysis of principal components) all indicated little affinity of isolate for source population. Of the 335 isolates, most unique MLG were found at the stratum of the individual leaflets (n = 242), with similar total numbers of unique MLG observed at the strata of the terminal (n = 170), tree (n = 166), and orchard (n = 165). Thus, the vast majority of shared clones existed on individual leaflets on a terminal at the scale of 10s of centimeters or less, indicating a notable component of short-distance dispersal. There was significant linkage disequilibrium (P < 0.001), and an analysis of Psex showed that where there were multiple encounters of an MLG, they were most probably the result of asexual reproduction (P < 0.05) but there was no evidence that asexual reproduction was involved in single or first encounters of an MLG (P > 0.05). Overall, the MAT1-1-1 and MAT1-2-1 idiomorphs were at equilibrium (73:92) and in most populations, subpopulations, and sub-subpopulations. Both mating types were frequently observed on the same leaflet. The results provide novel information on the characteristics of populations of V. effusa at fine spatial scales, and provide insights into the dispersal of the organism within and between trees. The proximity of both mating idiomorphs on single leaflets is further evidence of opportunity for development of the sexual stage in the field.


Plant Disease ◽  
2022 ◽  
Author(s):  
Roy Davis ◽  
Thomas Isakeit ◽  
Thomas Chappell

Fusarium wilt of cotton, caused by the soilborne fungal pathogen Fusarium oxysporum f. sp. vasinfectum (FOV), occurs in regions of the United States where cotton (Gossypium spp.) is grown. Race 4 of this pathogen (FOV4) is especially aggressive and does not require the co-occurrence of the root knot nematode (Meloidogyne incognita) to infect cotton. Its sudden appearance in far-west Texas in 2016 after many years of being restricted to California is of great concern, as is the threat of its continued spread through the cotton-producing regions of the United States. The aim of this research was to analyze the spatial variability of FOV4 inoculum density in the location where FOV4 is locally emerging, using quantitative and droplet digital polymerase chain reaction (qPCR and ddPCR) methods. Soil samples collected from a field with known FOV4 incidence in Fabens, Texas were analyzed. Appreciable variation in inoculum density was found to occur at spatial scales smaller than the size of plots involved in cultivar trial research, and was spatially autocorrelated (Moran’s I, Z = 17.73, p < 0.0001). These findings indicate that for cultivar trials, accounting for the spatial distribution of inoculum either by directly quantifying it or through the use of densely-distributed “calibration checks” is important to the interpretation of results.


Author(s):  
Michael B. McElroy

As discussed in Chapter 3, the transportation sector accounts for approximately a third of total emissions of CO2 in the United States, with a smaller fraction but a rapidly growing total in China. Combustion of oil, either as gasoline or diesel, is primarily responsible for the transportation- related emissions of both countries. Strategies to curtail overall emissions of CO2 must include plans for a major reduction in the use of oil in the transportation sector. This could be accomplished (1) by reducing demand for trans¬portation services; (2) by increasing the energy efficiency of the sector; or (3) by transitioning to an energy system less reliant on carbon- emitting sources of energy. Assuming continuing growth in the economies of both countries, option 1 is unlikely, certainly for China. Significant success has been achieved already in the United States under option 2, prompted by the application of increasingly more stringent corporate average fuel economy (CAFE) standards. And the technological advances achieved under this program are likely to find application in China and elsewhere, given the global nature of the automobile/ truck industry. The topic for discussion in this chapter is whether switching from oil to a plant- or animal- based fuel could contribute to a significant reduction in CO2 emissions from the transportation sector of either or both countries, indeed from the globe as a whole. The question is whether plant- based ethanol can substitute for gasoline and whether additional plant- and animal- derived products can cut back on demand for diesel. The related issue is whether this substitution can contribute at acceptable social and economic cost to a net reduction in overall CO2 emissions when account is taken of the entire lifecycle for production of the nonfossil alternatives. There is an extensive history to the use of ethanol as a motor fuel. Nicolas Otto, cred¬ited with the development of the internal combustion engine, used ethanol as the energy source for one of his early vehicle inventions in 1860. Henry Ford designed his first auto¬mobile, the quadricycle, to run on pure ethanol in 1896.


10.1068/a3469 ◽  
2001 ◽  
Vol 33 (10) ◽  
pp. 1807-1827 ◽  
Author(s):  
Becky Mansfield

Debates about the relationship between globalization and state power have often relied on a static view of spatial scales as discrete stages for social interaction. Focusing instead on the ‘production of scale’, several researchers have argued that globalization leads to rescaling of the state, as regulatory powers are realigned both upwards to supranational regimes and downwards to regional, local, and urban governance structures. Although this perspective quite usefully treats scale as relational, this ‘glocalization’ argument remains somewhat schematic and does not allow for a full range of possible scalar configurations. Highlighting instead heterogeneity of scalar relations, in this paper I analyze the ways that United States' fishery development in the North Pacific produced both national power and transnational economic activity. After extending political jurisdiction over waters up to 200 nautical miles from shore, the United States implemented fishery development policies that emphasized the ‘Americanization’ of the Alaska pollock fishery at the expense of an international, particularly Japanese, fishery. The outcomes of these policies, however, have been international partnerships, foreign direct investment, and increased international trade, all of which have made the pollock industry simultaneously national and transnational. Efforts to assert and implement control over ocean territory produced both the national state and globalization, which were mutually reinforcing rather than antagonistic. Treating national states and the global economy as complex, contingent scalar configurations facilitates analysis of the causes of variability in state – economy relations.


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