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1.
Increasing evidence suggests that climate change poses direct and indirect threats to national and human security. However, the degree to which such knowledge of the risks informs decision-making remains poorly understood for key security communities, including the U.S. Department of Defense. Here, through document analysis and interviews with climate security researchers and practitioners from the U.S. military community, we evaluate perceptions about and the degree to which (i) these individuals believe climate change is a threat to U.S. national security interests, and (ii) the U.S. Department of Defense integrates climate security science into its decision-making. Our research suggests a complex answer. Public statements and reports indicate U.S. Department of Defense leadership considers climate change a security threat of strategic importance, and most researchers interviewed believe the U.S. Department of Defense prioritizes climate security as a near-term threat. However, evidence of climate security threats is only selectively integrated into planning and decision-making. Interviews suggest several barriers and enablers to evidence-based decision-making within the U.S. Department of Defense. Barriers include mixed beliefs in the near-term urgency of the threat, changing political environments, and insufficient co-production of actionable science across the levels of war, including issues of data collection, sharing, and analysis. Enablers include increased awareness after climate-related impacts, strong leadership support, and knowledge transfer and convening forums. Improved insight into the production and use of climate security knowledge is crucial for the task of safeguarding human and national security in a changing climate.  相似文献   

2.
This paper asks whether extreme weather events are becoming more discernible. It uses the Vanderbilt University Television News Archives to determine if annual coverage given to heat waves, droughts, hurricanes and floods has increased on the network news between 1968 and 1996. An index of extreme weather events shows a clear trend toward increased coverage, especially since 1988. However, the different types of extreme events do not receive equal coverage: for example, annual peaks for droughts contain about twice as many stories as the peaks for heat waves. The data further reveal that there is no association between coverage of climate change and the overall coverage of extreme events. While extreme events have attracted more stories in the U.S., there has been no increase in the coverage devoted to extreme events in foreign countries. The possible effects of shifts in TV coverage on the public salience and understanding of climate change are discussed.  相似文献   

3.
The distribution of monthly mean error of NMC model forecasts and its seasonal variation are investi-gated.The ratio of monthly mean error to standard deviation is used here to find out that the region where acorrection of systematic error is needed and appropriate is mainly in low latitudes.The improvement,afterthe model's vertical resolution and some physical parameters were changed from April 1985,is investigated,andthe NMC operational model forecasts have also compared with those of ECMWF.  相似文献   

4.
A nested regional climate model is used to generate a scenario of climate change over the MINK region (Missouri, Iowa, Nebraska, Kansas) due to doubling of carbon dioxide concentration (2 × CO2) for use in agricultural impact assessment studies. Five-year long present day (control) and 2 × CO2 simulations are completed at a horizontal grid point spacing of 50 km. Monthly and seasonal precipitation and surface air temperature over the MINK region are reproduced well by the model in the control run, except for an underestimation of both variables during the spring months. The performance of the nested model in the control run is greatly improved compared to a similar experiment performed with a previous version of the nested modeling system by Giorgi et al. (1994). The nested model generally improves the simulation of spatial precipitation patterns compared to the driving general circulation model (GCM), especially during the summer. Seasonal surface warming of 4 to 6 K and seasonal precipitation increases of 6 to 24% are simulated in 2 × CO2 conditions. The control run temperature biases are smaller than the simulated changes in all seasons, while the precipitation biases are of the same order of magnitude as the simulated changes. Although the large scale patterns of change in the driving GCM and nested RegCM model are similar, significant differences between the models, and substantial spatial variability, occur within the MINK region.  相似文献   

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Developing appropriate management options for adapting to climate change is a new challenge for land managers, and integration of climate change concepts into operational management and planning on United States national forests is just starting. We established science–management partnerships on the Olympic National Forest (Washington) and Tahoe National Forest (California) in the first effort to develop adaptation options for specific national forests. We employed a focus group process in order to establish the scientific context necessary for understanding climate change and its anticipated effects, and to develop specific options for adapting to a warmer climate. Climate change scientists provided the scientific knowledge base on which adaptations could be based, and resource managers developed adaptation options based on their understanding of ecosystem structure, function, and management. General adaptation strategies developed by national forest managers include: (1) reduce vulnerability to anticipated climate-induced stress by increasing resilience at large spatial scales, (2) consider tradeoffs and conflicts that may affect adaptation success, (3) manage for realistic outcomes and prioritize treatments that facilitate adaptation to a warmer climate, (4) manage dynamically and experimentally, and (5) manage for structure and composition. Specific adaptation options include: (1) increase landscape diversity, (2) maintain biological diversity, (3) implement early detection/rapid response for exotic species and undesirable resource conditions, (4) treat large-scale disturbance as a management opportunity and integrate it in planning, (5) implement treatments that confer resilience at large spatial scales, (6) match engineering of infrastructure to expected future conditions, (7) promote education and awareness about climate change among resource staff and local publics, and (8) collaborate with a variety of partners on adaptation strategies and to promote ecoregional management. The process described here can quickly elicit a large amount of information relevant for adaptation to climate change, and can be emulated for other national forests, groups of national forests with similar resources, and other public lands. As adaptation options are iteratively generated for additional administrative units on public lands, management options can be compared, tested, and integrated into adaptive management. Science-based adaptation is imperative because increasing certainty about climate impacts and management outcomes may take decades.  相似文献   

7.
Subnational and non-governmental actors are expected to provide important contributions to broader climate actions. A consistent and accurate quantification of their GHG emissions is an important prerequisite for the success of such efforts. However, emissions embodied in domestic and international supply chains, that can undermine the effectiveness of climate agreements, add challenges to the quantification of emissions originating from the consumption of goods and services produced elsewhere. We examine emission transfers between the states that have joined the U.S. Climate Alliance (USCA) and others. Our results show that states pledging to curb emissions consistent with the Paris Agreement were responsible for approximately 40% of total U.S. territorial GHG emissions. However, when accounting for transferred emissions through international and interstate supply chains of the products they consume, the share of Alliance states increased to 52.4% of the national total GHG emissions. The consumption-based emissions for some Alliance states, such as Massachusetts and New York, could be more than 1.5 times higher than their production-based emissions. Our detailed sectoral analysis highlights the challenges facing such agreements to extend cooperation in the future for larger joint benefit given the potential for carbon leakage from member states implementing stricter environmental policies that could lead to higher emissions from non-member states. It is critical for these arrangements to pay close attention to transferred emissions.  相似文献   

8.
The tragic events of Sept. 11, 2001 resulted in suspension of commercial flights over North America. It has been suggested that the diurnal temperature range (DTR) increased due to an absence of airplane contrails. This study examined hourly data observed at 288 stations. The average DTR, temperature, maximum/minimum temperature and relative humidity were found for each day in 2001 and compared to the average value occurring during 1975–2005. For the coterminous U.S., the DTR averaged over the period Sept. 11–14, 2001 was about 1°C larger than that found for the 3?days prior and after the flight ban. However, the day-to-day DTR does not correlate well with the flight ban. Plots of the change in DTR throughout North America during Sept. 8–17 show changes consistent with the natural progression of weather systems.  相似文献   

9.
The resource dependency literature argues that intensifying processes of dependency can lead to poorer socioecological outcomes, but the effects of reducing dependency remain untested. Some scholars argue that it improves socioecological conditions, while other strands of research suggest that it causes economic hardship, as evidenced by the deaths of despair crisis. Here, I examine the asymmetric effects of fossil fuel dependency (measured as the energy production-consumption ratio, the share of exports from the mining sector, and the share of GDP from the mining sector) on the carbon intensity of well-being (CIWB) at the U.S. state-level. I do so by estimating dynamic asymmetric models with fixed effects estimation. I find that increases in all three measures are associated with increases in the CIWB. Decreases in the energy production-consumption ratio and the share of exports from the mining sector do not affect the CIWB, while a decrease in the share of GDP from the mining sector produces a proportional reduction in the CIWB relative to an increase. The estimated net effect of all three variables suggests that an increase in fossil fuel dependency increases the CIWB, while a decrease has no effect. When the CIWB is disaggregated, I find that changes in the energy production-consumption ratio are driving changes in emissions and that changes in the share of GDP from the mining sector are responsible for changes in health-adjusted life expectancy. Given that the net effect of a decrease in fossil fuel dependency is not statistically significant, I conclude by arguing that a planned, managed transition away from fossil fuel extraction is critical to ensuring simultaneous improvements in human and environmental well-being.  相似文献   

10.
ENSO teleconnections imply anomalous weather conditions, causing yield shortages, price fluctuations, and civil unrest. We estimate ENSO’s effect on U.S. county-level corn yield distributions and find that temperature and precipitation alone are not sufficient to summarize the effect of global climate on agriculture. We find that acreage-weighted aggregate impacts mask considerable spatial heterogeneity at the county-level for the mean, variance, and downside risk of corn yields. Impacts for mean yields range from ??24 to 33 % for El Niño and ??25 to 36 % for La Niña, with the geographical center of losses shifting from the Eastern to Western corn belt. ENSO’s effect on the variance of crop yields is highly localized and is not representative of a variance-preserving shift. We also find that downside risk impacts are large and spatially correlated across counties.  相似文献   

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The main goal of this work is to describe the anthropogenic energy flux (Q F) in the city of S?o Paulo, Brazil. The hourly, monthly, and annual values of the anthropogenic energy flux are estimated using the inventory method, and the contributions of vehicular, stationary, and human metabolism sources from 2004 to 2007 are considered. The vehicular and stationary sources are evaluated using the primary consumption of energy based on fossil fuel, bio fuel, and electricity usage by the population. The diurnal evolution of the anthropogenic energy flux shows three relative maxima, with the largest maxima occurring early in the morning (??19.9 Wm?2) and in the late afternoon (??20.3 Wm?2). The relative maximum that occurs around noontime (??19.6 Wm?2) reflects the diurnal pattern of vehicle traffic that seems to be specific to S?o Paulo. With respect to diurnal evolution, the energy flux released by vehicular sources (Q FV) contributes approximately 50% of the total anthropogenic energy flux. Stationary sources (Q FS) and human metabolism (Q FM) represent about 41% and 9% of the anthropogenic energy flux, respectively. For 2007, the monthly values of Q FV, Q FS, Q FM, and Q F are, respectively, 16.8?±?0.25, 14.3?±?0.16, 3.5?±?0.03, and 34.6?±?0.41?MJ?m?2?month?1. The seasonal evolution monthly values of Q FV, Q FS, Q FM, and Q F show a relative minimum during the summer and winter vacations and a systematic and progressive increase associated with the seasonal evolution of the economic activity in S?o Paulo. The annual evolution of Q F indicates that the city of S?o Paulo released 355.2?MJ?m?2?year?1 in 2004 and 415.5?MJ?m?2?year?1 in 2007 in association with an annual rate of increase of 19.6?MJ?m?2?year?1 (from 2004 to 2006) and 30.5?MJ?m?2?year?1 (from 2006 to 2007). The anthropogenic energy flux corresponds to about 9% of the net radiation at the surface in the summer and 15% in the winter. The amplitude of seasonal variation of the maximum hourly value of the diurnal variation increases exponentially with latitude.  相似文献   

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News organizations constitute key sites of science communication between experts and lay audiences, giving many individuals their basic worldview of complex topics like climate change. Previous researchers have studied climate change news coverage to assess accuracy in reporting and potential sources of bias. These studies typically rely on manually coding articles from a handful of prestigious outlets, not allowing comparisons with smaller newspapers or providing enough diversity to assess the influence of partisan orientation or localized climate vulnerability on content production. Making these comparisons, this study indicates that partisan orientation, scale of circulation, and vulnerability to climate change correlate with several topics present in U.S. newspaper coverage of climate change. After assembling a corpus of over 78,000 articles covering two decades from 52 U.S. newspapers that are diverse in terms of geography, partisan orientation, scale of circulation, and objectively measured climate risk, a coherent set of latent topics were identified via an automated content analysis of climate change news coverage. Topic model results indicate that while outlet bias does not appear to impact the prevalence of coverage for most topics surrounding climate change, differences were evident for some topics based on partisan orientation, scale, or vulnerability status, particularly those relating to climate change denial, impacts, mitigation, or resource use. Overall, this paper provides a comprehensive study of U.S. newspaper coverage of climate change and identifies specific topics where outlet bias constitutes an important contextual factor.  相似文献   

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Can near-term public support of renewable energy technologies contain the increase of mitigation costs due to delays of implementing emission caps at the global level? To answer this question we design a set of first and second best scenarios to analyze the impact of early deployment of renewable energy technologies on welfare and emission timing to achieve atmospheric carbon stabilization by 2100. We use the global multiregional energy?Ceconomy?Cclimate hybrid model REMIND-R as a tool for this analysis. An important design feature of the policy scenarios is the timing of climate policy. Immediate climate policy contains the mitigation costs at less than 1% even if the CO2 concentration target is 410?ppm by 2100. Delayed climate policy increases the costs significantly because the absence of a strong carbon price signal continues the carbon intensive growth path. The additional costs can be decreased by early technology policies supporting renewable energy technologies because emissions grow less, alternative energy technologies are increased in capacity and their costs are reduced through learning by doing. The effects of early technology policy are different in scenarios with immediate carbon pricing. In the case of delayed climate policy, the emission path can be brought closer to the first-best solution, whereas in the case of immediate climate policy additional technology policy would lead to deviations from the optimal emission path. Hence, technology policy in the delayed climate policy case reduces costs, but in the case of immediate climate policy they increase. However, the near-term emission reductions are smaller in the case of delayed climate policies. At the regional level the effects on mitigation costs are heterogeneously distributed. For the USA and Europe early technology policy has a positive welfare effect for immediate and delayed climate policies. In contrast, India looses in both cases. China loses in the case of immediate climate policy, but profits in the delayed case. Early support of renewable energy technologies devalues the stock of emission allowances, and this effect is considerable for delayed climate policies. In combination with the initial allocation rule of contraction and convergence a relatively well-endowed country like India loses and potential importers like the EU gain from early renewable deployment.  相似文献   

18.
The critical comments to the publications by the authors ofthe present paper that were given in [10] (the publications deal with the possible effects of gravity field inhomogeneities in the atmosphere and ocean) are discussed. In the authors' opinion, some remarks are groundless. At the same time, the authors agree with one of the important remarks that the results of their paper concerning studies of the ocean disturbances are to be reconsidered.  相似文献   

19.
The main goal of this work is to describe the diurnal and seasonal variations of the radiation balance components at the surface in the city of S?o Paulo based on observations carried out during 2004. Monthly average hourly values indicate that the amplitudes of the diurnal cycles of net radiation (Q*), downwelling and upwelling shortwave radiation (SWDW, SWUP), and longwave radiations (LWDW, LWUP) in February were, respectively, 37%, 14%, 19%, 11%, and 5% larger than they were in August. The monthly average daily values indicate a variation of 60% for Q*, with a minimum in June and a maximum in December; 45% for SWDW, with a minimum in May and a maximum in September; 50% for SWUP, with a minimum in June and a maximum in September; 13% for LWDW, with a minimum in July and a maximum in January; and 9% for LWUP, with a minimum in July and a maximum in February. It was verified that the atmospheric broadband transmissivity varied from 0.36 to 0.57; the effective albedo of the surface varied from 0.08 to 0.10; and the atmospheric effective emissivity varied from 0.79 to 0.92. The surface effective emissivity remained approximately constant and equal to 0.96. The albedo and surface effective emissivity for S?o Paulo agreed with those reported for urban areas in Europe and North America cities. This indicates that material and geometric effects on albedo and surface emissivity in S?o Paulo are similar to ones observed in typical middle latitudes cities. On the other hand, it was found that S?o Paulo city induces an urban heat island with daytime maximum intensity varying from 2.6°C in July (16:00 LT) to 5.5°C in September (15:00 LT). The analysis of the radiometric properties carried out here indicate that this daytime maximum is a primary response to the seasonal variation of daily values of net solar radiation at the surface.  相似文献   

20.
A thorough analysis of a proxy El Nino/Southern Oscillation (ENSO) record indicates that a bifurcation occurred in the ENSO system sometime around 5,000 years b.p. As a result of this bifurcation the attractor became higher dimensional and a new mechanism of instability was introduced. As a consequence of these changes the system switched from a dynamics where the normal condition (La Nina) was dominant to a dynamics characterized by more frequent and stronger El Nino events.  相似文献   

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