共查询到20条相似文献，搜索用时 31 毫秒
1.
It has long been accepted that the relative affluence and technological efficiency of nations are important contributors to their rate of emissions. These associations have, in turn, driven questions about the feasibility of mitigating anthropogenic greenhouse gas emissions through incremental transition to “business as usual” policy structures in variant social contexts. Here, I explore the extent to which the historical context of colonial relations impacts the feasibility of a nation mitigating emissions per capita, emissions per dollar, and total emissions under current development logics. To do so I examine the structure of variation for 152 nations during the 1960–2018 period. Subsequently, I examine how being situated as an extractive colony in the past serves to moderate the association of GDP per capita with CO 2 emissions per capita, CO 2 emissions per dollar, and total CO 2 emissions in the present. I find that roughly 11% of cross-national variation in CO 2 emissions per capita and CO 2 emissions per dollar, as well as nearly 6% of variation in total CO 2 emissions between 1960 and 2018 is attributable to having been historically subjected to extractive colonial processes. These findings suggest that mitigation of emissions through transition of “business as usual” policy structures appears significantly less feasible for nations positioned as extractive colonies in the past, relative to all others. 相似文献
2.
China is now the world's biggest annual emitter of greenhouse gases with 7467 million tons (Mt) carbon dioxide equivalent (CO2e) in 2005, with agriculture accounting for 11% of this total. As elsewhere, agricultural emissions mitigation policy in China faces a range of challenges due to the biophysical complexity and heterogeneity of farming systems, as well as other socioeconomic barriers. Existing research has contributed to improving our understanding of the technical potential of mitigation measures in this sector (i.e. what works). But for policy purposes it is important to convert these measures into a feasible economic potential, which provides a perspective on whether agricultural emissions reduction (measures) are low cost relative to mitigation measures and overall potential offered by other sectors of the economy. We develop a bottom-up marginal abatement cost curve (MACC) representing the cost of mitigation measures applicable in addition to business-as-usual agricultural practices. The MACC results demonstrate that while the sector offers a maximum technical potential of 402 MtCO2e in 2020, a reduction of 135 MtCO2e is potentially available at zero or negative cost (i.e. a cost saving), and 176 MtCO2e (approximately 44% of the total) can be abated at a cost below a threshold carbon price ≤¥ 100 (approximately €12) per tCO2e. Our findings highlight the relative cost effectiveness of nitrogen fertilizer and manure best management practices, and animal breeding practices. We outline the assumptions underlying MACC construction and discuss some scientific, socioeconomic and institutional barriers to realizing the indicated levels of mitigation. 相似文献
3.
《Climate Policy》2001,1(2):229-249
This article provides a first-cut estimate of the potential impacts of the clean development mechanism (CDM) on electricity generation and carbon emissions in the power sector of non-Annex 1 countries. We construct four illustrative CDM regimes that represent a range of approaches under consideration within the climate community. We examine the impact of these CDM regimes on investments in new generation, under illustrative carbon trading prices of US$ 10 and 100/t C. In the cases that are most conducive to CDM activity, roughly 94% of new generation investments remains identical to the without-CDM situation, with only 6% shifting from higher to lower carbon intensity technologies. We estimate that the CDM would bolster renewable energy generation by as little as 15% at US$ 10/t C, or as much as 300% at US$ 100/t C.A striking finding comes from our examination of the potential magnitude of the “free-rider” problem, i.e. crediting of activities that will occur even in the absence of the CDM. The CDM is intended to be globally carbon-neutral — a project reduces emissions in the host country but generates credits that increase emissions in the investor country. However, to the extent that unwarranted credits are awarded to non-additional projects, the CDM would increase global carbon emissions above the without-CDM emissions level. Under two of the CDM regimes considered, cumulative free-riders credits total 250–600 Mt C through the end of the first budget period in 2012. This represents 10–23% of the likely OECD emissions reduction requirement during the first budget period. Since such a magnitude of free-rider credits from non-additional CDM projects could threaten the environmental integrity of the Kyoto protocol, it is imperative that policy makers devise CDM rules that encourage legitimate projects, while effectively screening out non-additional activities. 相似文献
4.
Seagrass meadows are natural carbon storage hotspots at risk from global change threats, and their loss can result in the remineralization of soil carbon stocks and CO2 emissions fueling climate change. Here we used expert elicitation and empirical evidence to assess the risk of CO2 emissions from seagrass soils caused by multiple human-induced, biological and climate change threats. Judgments from 41 experts were synthesized into a seagrass CO2 emission risk score based on vulnerability factors (i.e., spatial scale, frequency, magnitude, resistance and recovery) to seagrass soil organic carbon stocks. Experts perceived that climate change threats (e.g., gradual ocean warming and increased storminess) have the highest risk for CO2 emissions at global spatial scales, while direct threats (i.e., dredging and building of a marina or jetty) have the largest CO2 emission risks at local spatial scales. A review of existing peer-reviewed literature showed a scarcity of studies assessing CO2 emissions following seagrass disturbance, but the limited empirical evidence partly confirmed the opinion of experts. The literature review indicated that direct and long-term disturbances have the greatest negative impact on soil carbon stocks per unit area, highlighting that immediate management actions after disturbances to recover the seagrass canopy can significantly reduce soil CO2 emissions. We conclude that further empirical evidence assessing global change threats on the seagrass carbon sink capacity is required to aid broader uptake of seagrass into blue carbon policy frameworks. The preliminary findings from this study can be used to estimate the potential risk of CO2 emissions from seagrass habitats under threat and guide nature-based solutions for climate change mitigation. 相似文献
5.
Studies of global environmental change make extensive use of scenarios to explore how the future can evolve under a consistent set of assumptions. The recently developed Shared Socioeconomic Pathways (SSPs) create a framework for the study of climate-related scenario outcomes. Their five narratives span a wide range of worlds that vary in their challenges for climate change mitigation and adaptation. Here we provide background on the quantification that has been selected to serve as the reference, or ‘marker’, implementation for SSP2. The SSP2 narrative describes a middle-of-the-road development in the mitigation and adaptation challenges space. We explain how the narrative has been translated into quantitative assumptions in the IIASA Integrated Assessment Modelling Framework. We show that our SSP2 marker implementation occupies a central position for key metrics along the mitigation and adaptation challenge dimensions. For many dimensions the SSP2 marker implementation also reflects an extension of the historical experience, particularly in terms of carbon and energy intensity improvements in its baseline. This leads to a steady emissions increase over the 21st century, with projected end-of-century warming nearing 4 °C relative to preindustrial levels. On the other hand, SSP2 also shows that global-mean temperature increase can be limited to below 2 °C, pending stringent climate policies throughout the world. The added value of the SSP2 marker implementation for the wider scientific community is that it can serve as a starting point to further explore integrated solutions for achieving multiple societal objectives in light of the climate adaptation and mitigation challenges that society could face over the 21st century. 相似文献
6.
Global agroecosystems can contribute to both climate change mitigation and biodiversity conservation, and market mechanisms provide a highly prospective means of achieving these outcomes. However, the ability of markets to motivate the supply of carbon sequestration and biodiversity services from agricultural land is uncertain, especially given the future changes in environmental, economic, and social drivers. We quantified the potential supply of these services from the intensive agricultural land of Australia from 2013 to 2050 under four global outlooks in response to a carbon price and biodiversity payment scheme. Each global outlook specified emissions pathways, climate, food demand, energy price, and carbon price modeled using the Global Integrated Assessment Model (GIAM). Using a simplified version of the Land Use Trade-Offs (LUTO) model, economic returns to agriculture, carbon plantings, and environmental plantings were calculated each year. The supply of carbon sequestration and biodiversity services was then quantified given potential land use change under each global outlook, and the sensitivity of the results to key parameters was assessed. We found that carbon supply curves were similar across global outlooks. Sharp increases in carbon sequestration supply occurred at carbon prices exceeding 50 $ tCO2−1 in 2015 and exceeding 65 $ tCO2−1 in 2050. Based on GIAM-modeled carbon prices, little carbon sequestration was expected at 2015 under any global outlook. However, at 2050 expected carbon supply under each outlook differed markedly, ranging from 0 to 189 MtCO2 yr−1. Biodiversity services of 3.32% of the maximum may be achieved in 2050 for a 1 $B investment under median scenario settings. We conclude that a carbon market can motivate supply of substantial carbon sequestration but only modest amounts of biodiversity services from agricultural land. A complementary biodiversity payment can synergistically increase the supply of biodiversity services but will not provide much additional carbon sequestration. The results were sensitive to global drivers, especially the carbon price, and the domestic drivers of adoption hurdle rate and agricultural productivity. The results can inform the design of an effective national policy and institutional portfolio addressing the dual objectives of climate change and biodiversity conservation that is robust to future uncertainty in both national and global drivers. 相似文献
7.
Carbon sequestration through ecological restoration programs is an increasingly important option to reduce the rise of atmospheric carbon dioxide concentration. China’s Grain for Green Program (GGP) is likely the largest centrally organized land-use change program in human history and yet its carbon sequestration benefit has yet to be systematically assessed. Here we used seven empirical/statistical equations of forest biomass carbon sequestration and five soil carbon change models to estimate the total and decadal carbon sequestration potentials of the GGP during 1999–2050, including changes in four carbon pools: aboveground biomass, roots, forest floor and soil organic carbon. The results showed that the total carbon stock in the GGP-affected areas was 682 Tg C in 2010 and the accumulative carbon sink estimates induced by the GGP would be 1697, 2635, 3438 and 4115 Tg C for 2020, 2030, 2040 and 2050, respectively. Overall, the carbon sequestration capacity of the GGP can offset about 3%–5% of China’s annual carbon emissions (calculated using 2010 emissions) and about 1% of the global carbon emissions. Afforestation by the GGP contributed about 25% of biomass carbon sinks in global carbon sequestration in 2000–2010. The results suggest that large-scale ecological restoration programs such as afforestation and reforestation could help to enhance global carbon sinks, which may shed new light on the carbon sequestration benefits of such programs in China and also in other regions. 相似文献
8.
Potential emissions of CO2 and methane from proved reserves of fossil fuels: An alternative analysis
Scientists have argued that no more than 275 GtC (IPCC, 2013) of the world’s reserves of fossil fuels of 746 GtC can be produced in this century if the world is to restrict anthropogenic climate change to ≤2 °C. This has raised concerns about the risk of these reserves becoming “stranded assets” and creating a dangerous “carbon bubble” with serious impacts on global financial markets, leading in turn to discussions of appropriate investor and consumer actions. However, previous studies have not always clearly distinguished between reserves and resources, nor differentiated reserves held by investor-owned and state-owned companies with the capital, infrastructure, and capacity to develop them in the short term from those held by nation-states that may or may not have such capacity. This paper analyzes the potential emissions of CO2 and methane from the proved reserves as reported by the world's largest producers of oil, natural gas, and coal. We focus on the seventy companies and eight government-run industries that produced 63% of the world’s fossil fuels from 1750 to 2010 (Heede, 2014), and have the technological and financial capacity to develop these reserves. While any reserve analysis is subject to uncertainty, we demonstrate that production of these reported reserves will result in emissions of 440 GtC of carbon dioxide, or 160% of the remaining 275 GtC carbon budget. Of the 440 GtC total, the 42 investor-owned oil, gas, and coal companies hold reserves with potential emissions of 44 GtC (16% of the remaining carbon budget, hereafter RCB), whereas the 28 state-owned entities possess reserves of 210 GtC (76% of the RCB). This analysis suggests that what may be needed to prevent dangerous anthropogenic interference (DAI) with the climate system differs when one considers the state-owned entities vs. the investor-owned entities. For the former, there is a profound risk involved simply in the prospect of their extracting their proved reserves. For the latter, the risk arises not so much from their relatively small proved reserves, but from their on-going exploration and development of new fossil fuel resources. For preventing DAI overall, effective action must include the state-owned companies, the investor-owned companies, and governments. However, given that the majority of the world's reserves are coal resources owned by governments with little capacity to extract them in the near term, we suggest that the more immediate urgency lies with the private sector, and that investor and consumer pressure should focus on phasing out these companies’ on-going exploration programs. 相似文献
9.
The United Nations-led international climate change negotiations in Paris in December 2015 (COP21) trigger and enhance climate action across the globe. This paper presents a model-based assessment of the Paris Agreement. In particular, we assess the mitigation policies implied by the Intended Nationally Determined Contributions (INDCs) put forward in the run-up to COP21 by individual member states and a policy that is likely to limit global warming to 2 °C above pre-industrial levels. We combine a technology-rich bottom-up energy system model with an economy-wide top-down CGE model to analyse the impact on greenhouse gas emissions, energy demand and supply, and the wider economic effects, including the implications for trade flows and employment levels. In addition, we illustrate how the gap between the Paris mitigation pledges and a pathway that is likely to restrict global warming to 2 °C can be bridged. Results indicate that energy demand reduction and a decarbonisation of the power sector are important contributors to overall emission reductions up to 2050. Further, the analysis shows that the Paris pledges lead to relatively small losses in GDP, indicating that global action to cut emissions is consistent with robust economic growth. The results for employment indicate a potential transition of jobs from energy-intensive to low-carbon, service oriented sectors. 相似文献
10.
This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 400–1200 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO2 emissions of the baseline scenarios range from about 25 GtCO2 to more than 120 GtCO2 per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: (1) the policy assumptions, (2) the socio-economic narrative, and (3) the stringency of the target. The carbon price for reaching the target of 2.6 W/m2 that is consistent with a temperature change limit of 2 °C, differs in our analysis thus by about a factor of three across the SSP marker scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quantifications span a wide range of different futures broadly representative of the current literature. This allows their subsequent use and development in new assessments and research projects. Critical next steps for the community scenario process will, among others, involve regional and sectoral extensions, further elaboration of the adaptation and impacts dimension, as well as employing the SSP scenarios with the new generation of earth system models as part of the 6th climate model intercomparison project (CMIP6). 相似文献
11.
Global average sea levels are expected to rise by up to a metre by the end of the century. This long-term rise will combine with shorter-term changes in sea level (e.g. high tides, storm surges) to increase risks of flooding and erosion in vulnerable coastal areas. As communities become increasingly exposed to these risks, understanding their beliefs and responses becomes more important. While studies have explored public responses to climate change, less research has focused on perceptions of the specific risks associated with sea-level change. This paper presents the results of a mental models study that addressed this knowledge gap by exploring expert and public perceptions of sea-level change on the Severn Estuary, a threatened coastal environment in the southwest of the United Kingdom. A model was developed from the literature and expert interviews (N = 11), and compared with public perceptions elicited via interviews (N = 20) and a quantitative survey (N = 359). Whilst we find a high degree of consistency between expert and public understandings, there are important differences that have implications for how sea level risks are interpreted and for what are perceived as appropriate mitigation and adaptation practices. We also find a number of potential barriers to engaging with the issue: individuals express low concern about sea-level change in relation to other matters; they feel detached from the issue, seeing it as something that will happen in future to other people; and many perceive that neither the causes of nor responses to sea-level change are their responsibility. We point to areas upon which future risk communications should therefore concentrate. 相似文献
12.
《Atmospheric Research》2009,91(2-4):243-252
Aerosol size distributions were measured with Micro Orifice Uniform Deposit Impactor (MOUDI) cascade impactors at the rural Angiola and urban Fresno Supersites in California's San Joaquin Valley during the California Regional PM10/PM2.5 Air Quality Study (CRPAQS) winter campaign from December 15, 2000 to February 3, 2001. PM2.5 filter samples were collected concurrently at both sites with Sequential Filter Samplers (SFS). MOUDI nitrate (NO3−) concentrations reached 66 μg/m3 on January 6, 2001 during the 1000–1600 PST (GMT-8) period. Pair-wise comparisons between PM2.5 MOUDI and SFS concentrations revealed high correlations at the Angiola site (r > 0.93) but more variability (r < 0.85) at the Fresno site for NO3−, sulfate (SO4=), and ammonium (NH4+). Correlations were higher at Fresno (r > 0.87) than at Angiola (r < 0.7) for organic carbon (OC), elemental carbon (EC), and total carbon (TC). NO3− and SO4= size distributions in Fresno were multi-modal and wider than the uni-modal distributions observed at Angiola. Geometric mean diameters (GMD) were smaller for OC and EC than for NO3− and SO4= at both sites. OC and EC were more concentrated on the lowest MOUDI stage (0.056 µm) at Angiola than at Fresno. The NO3− GMD increased from 0.97 to 1.02 µm as the NO3− concentration at Angiola increased from 43 to 66 µg m− 3 during a PM2.5 episode from January 4–7, 2001. There was a direct relationship between GMD and NO3− and SO4= concentrations at Angiola but no such relationships for OC or EC. This demonstrates that secondary aerosol formation increases both concentration and particle size for the rural California environment. 相似文献
13.
Climate output from the UK Hadley Centre's HadCM2 and HadCM3 experiments for the period 1860 to 2100, with IS92a greenhouse gas forcing, together with predicted patterns of N deposition and increasing CO2, were input (offline) to the dynamic vegetation model, Hybrid v4.1 (Friend et al., 1997; Friend and White, 1999). This model represents biogeochemical, biophysical and biogeographical processes, coupling the carbon, nitrogen and water cycles on a sub-daily timestep, simulating potential vegetation and transient changes in annual growth and competition between eight generalized plant types in response to climate.Global vegetation carbon was predicted to rise from about 600 to 800 PgC (or to 650 PgC for HadCM3) while the soil carbon pool of about 1100 PgC decreased by about 8%. By the 2080s, climate change caused a partial loss of Amazonian rainforest, C4 grasslands and temperate forest in areas of southern Europe and eastern USA, but an expansion in the boreal forest area. These changes were accompanied by a decrease in net primary productivity (NPP) of vegetation in many tropical areas, southern Europe and eastern USA (in response to warming and a decrease in rainfall), but an increase in NPP of boreal forests. Global NPP increased from 45 to 50 PgC y−1 in the 1990s to about 65 PgC y−1 in the 2080s (about 58 PgC y−1 for HadCM3). Global net ecosystem productivity (NEP) increased from about 1.3 PgC y−1 in the 1990s to about 3.6 PgC y−1 in the 2030s and then declined to zero by 2100 owing to a loss of carbon from declining forests in the tropics and at warm temperate latitudes — despite strengthening of the carbon sink at northern high latitudes. HadCM3 gave a more erratic temporal evolution of NEP than HadCM2, with a dramatic collapse in NEP in the 2050s. 相似文献
14.
Baojing Gu Ying Ge Scott X. Chang Weidong Luo Jie Chang 《Global Environmental Change》2013,23(5):1112-1121
Identifying the sources of reactive nitrogen (N) and quantifying their contributions to groundwater nitrate concentrations are critical to understanding the dynamics of groundwater nitrate contamination. Here we assessed groundwater nitrate contamination in China using literature analysis and N balance calculation in coupled human and natural systems. The source appointment via N balance was well validated by field data via literature analysis. Nitrate was detected in 96% of groundwater samples based on a common detection threshold of 0.2 mg N L?1, and 28% of groundwater samples exceeded WHO's maximum contaminant level (10 mg N L?1). Groundwater nitrate concentrations were the highest beneath industrial land (median: 34.6 mg N L?1), followed by urban land (10.2 mg N L?1), cropland (4.8 mg N L?1), and rural human settlement (4.0 mg N L?1), with the lowest found beneath natural land (0.8 mg N L?1). During the period 1980–2008, total reactive N leakage to groundwater increased about 1.5 times, from 2.0 to 5.0 Tg N year?1, in China. Despite that the contribution of cropland to the total amount of reactive N leakage to groundwater was reduced from 50 to 40% during the past three decades, cropland still was the single largest source, while the contribution from landfill rapidly increased from 10 to 34%. High reactive N leakage mainly occurred in relatively developed agricultural or urbanized regions with a large population. The amount of reactive N leakage to groundwater was mainly driven by anthropogenic factors (population, gross domestic product, urbanization rate and land use type). We constructed a high resolution map of reactive N source appointment and this could be the basis for future modeling of groundwater nitrate dynamics and for policy development on mitigation of groundwater contamination. 相似文献
15.
《Atmospheric Research》2009,91(2-4):253-263
A high-volume cascade impactor, equipped with a PM10 inlet, was used to collect size-segregated aerosol samples during the summer of 2004 at two Portuguese locations: a coastal-rural area (Moitinhos) and an urban area (Oporto). Concentrations of airborne particulate matter (PM), total carbon (TC), organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were determined for the following particle size ranges: < 0.49, 0.49–0.95, 0.95–3.0, and 3.0–10 µm. The total PM mass concentrations at the urban and coastal-rural sites ranged from 22.8 to 79.6 μg m− 3 and 19.9 to 28.2 μg m− 3, respectively, and more than 56% of the total aerosol mass was found in the fractions below 3.0 μm. At both locations the highest concentrations of OC and EC were found in the submicrometer size range. The regional variability for the OC and EC concentrations, with the highest concentrations being found in the urban area, was related to the contribution of local primary sources (mostly traffic emissions). It was also verified an enrichment of the small size particles in WSOC, representing on average 37.3(± 12.4)% and 59.7(± 18.0)% of OC in the very fine aerosol at the coastal-rural and urban areas, respectively. The amount of secondary OC calculated by the minimum OC/EC ratio method indicates that secondary organic aerosol formation was important throughout the study at both sites. The obtained results suggest that long-range transport and favourable summer conditions for photochemical oxidation are key factors determining secondary OC formation in the coastal-rural and urban areas. The ultraviolet absorption properties of the chromophoric constituents of the WSOC fractions were also different among the different particle size ranges and also between the two sampling locations, thus suggesting the strong impact of the diverse emission sources into the composition of the size-segregated organic aerosol. 相似文献
16.
《Global Environmental Change》2007,17(2):260-280
This paper presents a set of technically feasible multi-gas emission pathways (envelopes) for stabilising greenhouse gas concentration at 450, 550 and 650 ppm CO2-equivalent and their trade-offs between direct abatement costs and probabilities to meet temperature targets. There are different pathways within the envelope. Delayed response pathways initially follow the upper boundary of the emission envelope and reduce more by the end of the century. In contrast, early action pathways first follow the lower boundary and then the upper boundary. The latter require an early peak in the global emissions but keeps the option open for shifting to lower concentration targets in the future. Costs evaluations depend on the discount rate. Early action profiles have high costs early on, but learning-by-doing and smoother reduction rates over time lead to in most cases to lower costs across the century (net present value (NPV)). To achieve the 450 ppm CO2-equivalent, the global emissions need to peak before 2020. The NPV of costs increase from 0.2% of cumulative gross domestic product to 1.0% as the shift is made from 650 to 450 ppm (discount rate 5%). However, the chances of limiting global mean warming to 2 °C above pre-industrial levels are very small for peaking and stabilisation at 650 ppm (1–23%) and 550 ppm (1–48%), but increase for a peaking at 510 ppm with subsequent stabilisation 450 ppm to 14–67%. 相似文献
17.
Concentrations and flux densities of methane were determined during a Lagrangian study of an advective filament in the permanent upwelling region off western Mauritania. Newly upwelled waters were dominated by the presence of North Atlantic Central Water and surface CH4 concentrations of 2.2 ± 0.3 nmol L−1 were largely in equilibrium with atmospheric values, with surface saturations of 101.7 ± 14%. As the upwelling filament aged and was advected offshore, CH4 enriched South Atlantic Central Water from intermediate depths of 100–350 m was entrained into the surface mixed layer of the filament following intense mixing associated with the shelf break. Surface saturations increased to 198.9 ± 15% and flux densities increased from a mean value over the shelf of 2.0 ± 1.1 μmol m−2 d−1 to a maximum of 22.6 μmol m−2 d−1. Annual CH4 emissions for this persistent filament were estimated at 0.77 ± 0.64 Gg which equates to a maximum of 0.35% of the global oceanic budget. This raises the known outgassing intensity of this area and highlights the importance of advecting filaments from upwelling waters as efficient vehicles for air-sea exchange. 相似文献
18.
Past research suggests that how we perceive risk can be related to how we attribute responsibility for risk-related issues, such as climate change; however, a gap in research lies in exploring possible connections between attribution of responsibility, risk perception, and information processing. Using the Risk Information Seeking and Processing model, this study fills this gap by examining how RISP-based variables are related to information processing and whether attribution of responsibility for mitigating climate change influences communication behaviors that are often predicted by elevated risk perceptions. Undergraduates at two large research universities (N = 572) were randomly assigned to read one of two newspaper articles that emphasized either individual responsibility (by highlighting personal actions) or societal responsibility (by highlighting government policy) for climate change mitigation. Results indicate that subjects in the individual responsibility condition were significantly more likely to process the message in a systematic manner; however, attribution of responsibility did not interact with risk perception to influence systematic processing. Moreover, attitudes toward climate change information and negative affect mediated the relationship between other key variables and systematic processing. These and other findings suggest that strategic communication about climate change may benefit from emphasizing individual responsibility to attract more attention from diverse audiences and to promote deeper thinking about the issue. Additional theoretical implications are presented. 相似文献
19.
Asude Hanedar Kadir Alp Burcak Kaynak Jaemeen Baek Edip Avsar M. Talat Odman 《Atmospheric Research》2011,99(3-4):391-399
The chemical mass balance model was applied to atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) in Istanbul, Turkey. A total of 326 airborne samples were collected and analyzed for 16 PAHs and Total Suspended Particles (TSP) in the September 2006–December 2007 period at three monitoring stations: Yildiz, DMO (urban sites) and Kilyos (rural site). The total average PAH concentrations were 100.66 ± 61.26, 84.63 ± 46.66 and 25.12 ± 13.34 ng m?3 and the TSP concentrations were 101.16 ± 53.22, 152.31 ± 99.12, 49.84 ± 18.58 μg m?3 for Yildiz, DMO and Kilyos stations respectively. At all the sites, the lighter compounds were the most abundant, notably Nap, AcPy and PA. The average correlation values between TSP and total heavier PAH were greater than 0.5 for Yildiz and DMO stations. The patterns of PAH and TSP concentrations showed spatial and temporal variations. PAH concentrations were evaluated for the PAH contribution from four sources (diesel engines, gasoline engines, natural gas combustion, and coal + wood burning). Vehicle emissions appear to be the major source with contributions of 61.2%, 63.3% and 54.1% for Yildiz, DMO and Kilyos stations respectively. Seasonal and yearly variations had different trends for all sites. 相似文献
20.
Deforestation has contributed significantly to net greenhouse gas emissions, but slowing deforestation, regrowing forests and other ecosystem processes have made forests a net sink. Deforestation will still influence future carbon fluxes, but the role of forest growth through aging, management, and other silvicultural inputs on future carbon fluxes are critically important but not always recognized by bookkeeping and integrated assessment models. When projecting the future, it is vital to capture how management processes affect carbon storage in ecosystems and wood products. This study uses multiple global forest sector models to project forest carbon impacts across 81 shared socioeconomic (SSP) and climate mitigation pathway scenarios. We illustrate the importance of modeling management decisions in existing forests in response to changing demands for land resources, wood products and carbon. Although the models vary in key attributes, there is general agreement across a majority of scenarios that the global forest sector could remain a carbon sink in the future, sequestering 1.2–5.8 GtCO2e/yr over the next century. Carbon fluxes in the baseline scenarios that exclude climate mitigation policy ranged from −0.8 to 4.9 GtCO2e/yr, highlighting the strong influence of SSPs on forest sector model estimates. Improved forest management can jointly increase carbon stocks and harvests without expanding forest area, suggesting that carbon fluxes from managed forests systems deserve more careful consideration by the climate policy community. 相似文献