Abatement of Greenhouse Gases: Does Location Matter?     

Terje Berntsen  Jan Fuglestvedt  Gunnar Myhre  Frode Stordal  Tore F. Berglen 《Climatic change》2006,74(4):377-411

Today's climate policy is based on the assumption that the location of emissions reductions has no impact on the overall climate effect. However, this may not be the case since reductions of greenhouse gases generally will lead to changes in emissions of short-lived gases and aerosols. Abatement measures may be primarily targeted at reducing CO₂, but may also simultaneously reduce emissions of NO_x, CO, CH₄ and SO₂ and aerosols. Emissions of these species may cause significant additional radiative forcing. We have used a global 3-D chemical transport model and a radiative transfer model to study the impact on climate in terms of radiative forcing for a realistic change in location of the emissions from large-scale sources. Based on an assumed 10% reduction in CO₂ emissions, reductions in the emissions of other species have been estimated. Climate impact for the SRES A1B scenario is compared to two reduction cases, with the main focus on a case with emission reductions between 2010 and 2030, but also a case with sustained emission reductions. The emission reductions are applied to four different regions (Europe, China, South Asia, and South America). In terms of integrated radiative forcing (over 100 yr), the total effect (including only the direct effect of aerosols) is always smaller than for CO₂ alone. Large variations between the regions are found (53–86% of the CO₂ effect). Inclusion of the indirect effects of sulphate aerosols reduces the net effect of measures towards zero. The global temperature responses, calculated with a simple energy balance model, show an initial additional warming of different magnitude between the regions followed by a more uniform reduction in the warming later. A major part of the regional differences can be attributed to differences related to aerosols, while ozone and changes in methane lifetime make relatively small contributions. Emission reductions in a different sector (e.g. transportation instead of large-scale sources) might change this conclusion since the NO_x to SO₂ ratio in the emissions is significantly higher for transportation than for large-scale sources. The total climate effect of abatement measures thus depends on (i) which gases and aerosols are affected by the measure, (ii) the lifetime of the measure implemented, (iii) time horizon over which the effects are considered, and (iv) the chemical, physical and meteorological conditions in the region. There are important policy implications of the results. Equal effects of a measure cannot be assumed if the measure is implemented in a different region and if several gases are affected. Thus, the design of emission reduction measures should be considered thoroughly before implementation.  相似文献   

Guided Waves from Sources Outside Faults: An Indication for Shallow Fault Zone Structure?   总被引：1，自引：0，他引：1  

Miko Fohrmann  Heiner Igel  Gunnar Jahnke  Yehuda Ben-Zion 《Pure and Applied Geophysics》2004,161(11-12):2125-2137

— Using 3-D numerical modeling of seismic wave propagation we investigate the possibility of generating fault zone (FZ) trapped wave energy from sources well outside a fault. The FZ is represented by a O(200 m) wide vertical low velocity layer in a half space. We find that FZ trapped waves can be excited from sources well outside the fault if (1) the low-velocity structure extemds only to shallow depth and the source is located at greater depth or (2) the structure of the low-velocity zone is such that only the shallow part of the FZ traps energy. FZ trapped waves are not excited from sources well outside a FZ continuous with depth. The results support, in conjunction with recent observational evidence, a model for natural faults with shallow trapping structures rather than ones that span the entire seismogenic zone. This may have implications for fault mechanics as well as for aspects of shaking hazard near faults.  相似文献   

Holtedahlite, a new magnesium phosphate from Modum, Norway     

Gunnar Raade  Micael H. Mladeck 《Lithos》1979,12(4):283-287

Holtedahlite occurs in a serpentine-magnesite deposit at Modum in association with althausite and (OH,F) apatite. It is colourless, transparent, has a vitreous lustre, occurs in massive form and shows no cleavage. The Mohs' hardness is $\text{4}\text{1}\text{2}\text{?5}$; specific gravity 2.94(2) (Berman balance), calculated density 2.936 g/cm³. It is uniaxial negative, ω = 1.599(1), ? = 1.597(1).Chemical analysis with the electron microprobe and separate determinations of CO₂ and H₂O give a formula close to Mg₂PO₄OH or more specifically (Mg,Na)₂(PO₄, CO₃OH)(OH,F). Holtedahlite is hexagonal, $\text{α = 11.188(2), c = 4.975(1)}\text{A}\text{?}\text{, V = 539.3(3)}\text{A}\text{?}{}^3\text{Z = 6}$, space group $\text{P321, P3m}\text{l}\text{or}\text{P}\text{3}\text{m}\text{l}$. The strongest lines in the X-ray powder pattern are (in Å, with intensities and indices): 3.722(90) ($\text{11}\text{2}\text{1}$), 3.475(50) ($\text{20}\text{2}\text{1}$), 3.234(30) ($\text{30}\text{3}\text{0}$), 2.796(30), 2.438(100) ($\text{22}\text{4}\text{1}$), 2.177(30) (2.177(30) ($\text{40}\text{4}\text{1}$), 1.859(30) ($\text{22}\text{4}\text{2}$). The infrared spectrum shows the presence of OH^?, CO₃^2?, and PO₄^3? and indicates an O-H… O distance of ca. 3.02 Å.  相似文献   

Althausite,a new mineral from Modum,Norway     

Gunnar Raade  Magne Tysseland 《Lithos》1975,8(3):215-219

Althausite occurs as cleavable masses in serpentine-magnesite deposits at Modum, Norway. The proposed formula in Mg₂PO₄ (OH_0.37F_0.25O_0.10)_0.81 with partly vacant halide sites. It is orthorhombic, space group Pna2₁, $\text{a}\text{= 8.258,}\text{b}\text{= 14.383,}\text{c}\text{= 6.054}\text{A}\text{?}\text{, Z}\text{= 8.}\text{D(meas)}\text{=2.97, ?(}\text{calc}\text{) = 2.91}\text{g/cm}{}^3\text{(}\text{X-ray}\text{), ?(}\text{calc}\text{) = 3.06}\text{g/cm}{}^3\text{(}\text{Gladstone-Dale}\text{),}\text{H}\text{= 3}\text{1}\text{2}\text{?4.}$ The strongest X-ray powder lines (41 given, FeKα radiation) with intensities and indices are 3.593 (100)(040), 3.316 (90)(211), 3.024 (80)(002), 2.786 (60)(112), 2641 (60)(122).The mineral is light grey with vitreous lustre, running brown on alteration to apatite. Non-fluorescent. Perfect cleavage {001}, distinct cleavage {101}. It is biaxial positive, α=1.588, β=1.592, γ=1.598, 2V_γ(calc)=78.5°, negative elongation, X=b, Y=c, Z=a. IR, DTA and TGA data are given.  相似文献   

Exploration and exploitation of natural heat in Iceland     

Gunnar Bödvarsson 《Bulletin of Volcanology》1960,23(1):241-250

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Studies of Northeast Atlantic species of redfish (genus Sebastes) by protein polymorphism     

Nedreaas  Kjell; Naevdal  Gunnar 《ICES Journal of Marine Science》1989,46(1):76-93

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A large-mesh salmon trap: a way of mitigating seal impact on a coastal fishery   总被引：1，自引：2，他引：1  

Lunneryd  Sven Gunnar; Fjalling  Arne; Westerberg  Hakan 《ICES Journal of Marine Science》2003,60(6):1194-1199

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Carbon chemistry and groundwater dynamics at natural analogue site Ruprechtov, Czech Republic: Insights from environmental isotopes     

Ulrich Noseck  Kazimierz Rozanski  Marek Dulinski  Vclava Havlov  Ondra Sracek  Thomas Brasser  Mirek Hercik  Gunnar Buckau 《Applied Geochemistry》2009,24(9):1765-1776

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Economic impacts of alternative greenhouse gas emission metrics: a model-based assessment     

Jessica Strefler  Gunnar Luderer  Tino Aboumahboub  Elmar Kriegler 《Climatic change》2014,125(3-4):319-331

In this paper we study the impact of alternative metrics on short- and long-term multi-gas emission reduction strategies and the associated global and regional economic costs and emissions budgets. We compare global warming potentials with three different time horizons (20, 100, 500 years), global temperature change potential and global cost potentials with and without temperature overshoot. We find that the choice of metric has a relatively small impact on the CO₂ budget compatible with the 2° target and therefore on global costs. However it substantially influences mid-term emission levels of CH₄, which may either rise or decline in the next decades as compared to today’s levels. Though CO₂ budgets are not affected much, we find changes in CO₂ prices which substantially affect regional costs. Lower CO₂ prices lead to more fossil fuel use and therefore higher resource prices on the global market. This increases profits of fossil-fuel exporters. Due to the different weights of non-CO₂ emissions associated with different metrics, there are large differences in nominal CO₂ equivalent budgets, which do not necessarily imply large differences in the budgets of the single gases. This may induce large shifts in emission permit trade, especially in regions where agriculture with its high associated CH₄ emissions plays an important role. Furthermore it makes it important to determine CO₂ equivalence budgets with respect to the chosen metric. Our results suggest that for limiting warming to 2 °C in 2100, the currently used GWP100 performs well in terms of global mitigation costs despite its conceptual simplicity.  相似文献   

Is atmospheric carbon dioxide removal a game changer for climate change mitigation?     

Elmar Kriegler  Ottmar Edenhofer  Lena Reuster  Gunnar Luderer  David Klein 《Climatic change》2013,118(1):45-57

The ability to directly remove carbon dioxide from the atmosphere allows the decoupling of emissions and emissions control in space and time. We ask the question whether this unique feature of carbon dioxide removal technologies fundamentally alters the dynamics of climate mitigation pathways. The analysis is performed in the coupled energy-economy-climate model ReMIND using the bioenergy with CCS route as an application of CDR technology. BECCS is arguably the least cost CDR option if biomass availability is not a strongly limiting factor. We compare mitigation pathways with and without BECCS to explore the impact of CDR technologies on the mitigation portfolio. Effects are most pronounced for stringent climate policies where BECCS is a key technology for the effectiveness of carbon pricing policies. The decoupling of emissions and emissions control allows prolonging the use of fossil fuels in sectors that are difficult to decarbonize, particularly in the transport sector. It also balances the distribution of mitigation costs across future generations. CDR is not a silver bullet technology. The largest part of emissions reductions continues to be provided by direct mitigation measures at the emissions source. The value of CDR lies in its flexibility to alleviate the most costly constraints on mitigating emissions.  相似文献