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The Chinook salmon (Oncorhynchus tshawytscha) spawns and rears in the cold, freshwater rivers and tributaries of California’s Central Valley, with four separate seasonal runs including fall and late-fall runs, a winter run, and a spring run. Dams and reservoirs have blocked access to most of the Chinook’s ancestral spawning areas in the upper reaches and tributaries. Consequently, the fish rely on the mainstem of the Sacramento River for spawning habitat. Future climatic warming could lead to alterations of the river’s temperature regime, which could further reduce the already fragmented Chinook habitat. Specifically, increased water temperatures could result in spawning and rearing temperature exceedences, thereby jeopardizing productivity, particularly in drought years. Paradoxically, water management plays a key role in potential adaptation options by maintaining spawning and rearing habitat now and in the future, as reservoirs such as Shasta provide a cold water supply that will be increasingly needed to counter the effects of climate change. Results suggest that the available cold pool behind Shasta could be maintained throughout the summer assuming median projections of mid-21st century warming of 2°C, but the maintenance of the cold pool with warming on the order of 4°C could be very challenging. The winter and spring runs are shown to be most at risk because of the timing of their reproduction.  相似文献   

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A key climate policy issue and debate is the future trajectory of emissions of carbon dioxide of countries, their peaking dates, and rates of decline after peaking. This article analyses China’s emissions trajectory in terms of global historical trends distinguishing between industry, infrastructure, and urbanization. Growth of emissions from industrialization and infrastructure development has stabilized in 2014 with saturation levels being reached, while the process of urbanization continues with the shift of the economy to the services sector, with reduced energy use, and this is a global trend. The future trajectory of emissions will be shaped largely by growth of transport and building-related services which directly impact on and are shaped by middle-class levels of well-being. These are areas where convergence with levels of services in other urbanized countries is an important element of national policy. This global trend has not been adequately taken into account in modelling and macroeconomic analysis which ignore social processes. The article concludes that China’s 13th Five Year Plan (2016–2020) seeks to achieve a ‘moderately well-off society’ while putting a cap on total energy demand by modifying the drivers of consumption emissions compared with countries that urbanized earlier. The adoption of a public policy priority of dense mixed-use urban form, public transport, energy efficiency to enable energy system reform, and digital economy could be a model for others.

Policy relevance

The article redefines climate change in terms of social processes as urban form and notions of well-being lock-in increasing levels of future emissions of carbon dioxide. There are implications for research in assessing how best drivers of emissions can be modified without affecting well-being, including renewable and digital technologies and human behaviours that drive patterns of natural resource use as well as the identification of leverage points. There are also broader implications for replacing the development cooperation model of global climate governance to focus on new values recognizing interdependencies for sharing responsibility as well as prosperity.  相似文献   


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Water temperature influences the distribution, abundance, and health of aquatic organisms in stream ecosystems, so understanding the impacts of climate warming on stream temperature will help guide management and restoration. This study assesses climate warming impacts on stream temperatures in California’s west-slope Sierra Nevada watersheds, and explores stream temperature modeling at the mesoscale. We used natural flow hydrology to isolate climate induced changes from those of water operations and land use changes. A 21 year time series of weekly streamflow estimates from WEAP21, a spatially explicit rainfall-runoff model were passed to RTEMP, an equilibrium temperature model, to estimate stream temperatures. Air temperature was uniformly increased by 2°C, 4°C, and 6°C as a sensitivity analysis to bracket the range of likely outcomes for stream temperatures. Other meteorological conditions, including precipitation, were unchanged from historical values. Raising air temperature affects precipitation partitioning into snowpack, runoff, and snowmelt in WEAP21, which change runoff volume and timing as well as stream temperatures. Overall, stream temperatures increased by an average of 1.6°C for each 2°C rise in air temperature, and increased most during spring and at middle elevations. Viable coldwater habitat shifted to higher elevations and will likely be reduced in California. Thermal heterogeneity existed within and between basins, with the high elevations of the southern Sierra Nevada and the Feather River watershed most resilient to climate warming. The regional equilibrium temperature modeling approach used here is well suited for climate change analysis because it incorporates mechanistic heat exchange, is not overly data or computationally intensive, and can highlight which watersheds are less vulnerable to climate warming. Understanding potential changes to stream temperatures from climate warming will affect how fish and wildlife are managed, and should be incorporated into modeling studies, restoration assessments, and licensing operations of hydropower facilities to best estimate future conditions and achieve desired outcomes.  相似文献   

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In this essay we discuss the development of and estimation of uncertainties in the global surface temperature record. We briefly discuss the similarities in and differences between the records from the institutions that produce such series. We then consider the numerous issues that must be addressed to enable accurate estimates to be derived. We consider these in their order of importance with respect to the record: biases in the sea surface temperature data, exposure of land-based thermometers before about 1900, urbanization effects in some series, and, finally, the homogeneity of individual land-based records.  相似文献   

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Theoretical and Applied Climatology - In this paper, robust statistical methods (including the climatic tendency ratio, inverse distance weight (IDW), and Mann-Kendall’s non-parametric...  相似文献   

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The fate of alpine species in response to climate warming is still unclear. We analyze effects of climate warming on the composition of alpine plants communities and unravel the range filling of communities within a belt from long-term true upward shift processes. In the European Alps we re-sampled in 2003 the vegetation at sites studied in 1953 and analyzed the changes at intra- and inter-community level. Since 1953 all communities experienced a high species turnover, leading to an overall increase in species richness as new species exceeded species losses. The dominant species mainly declined allowing the potential expansion of competitors and/or of new species. The main recruitment sources are neighbor communities within the same elevation belt performing biotic exchanges with other plant communities in the same altitudinal belts. The changes of species distribution curves with elevation emphasized that more than half of the most widespread persisting species exhibited downward shifts instead of upward shifts. Upward shifts from lower elevation belts and of nonnative species were very limited. One third of the persisting species declined and could be used as a proxy to measure the extinction debt. Therefore the fate of plant communities will depend on the ability of the original species to persist and fill the available ecological gaps. Species persistence may be crucial in developing adaptation and environmental protection strategies.  相似文献   

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Since the World War II, many economies have transitioned from an agrarian, biomass-based to an industrial, minerals-based metabolic regime. Since 1950, world population grew by factor 2.7 and global material consumption by factor 3.7–71 Gigatonnes per year in 2010. The expansion of the resource base required by human societies is associated with growing pressure on the environment and infringement on the habitats of other species. In order to achieve a sustainability transition, we require a better understanding of the currently ongoing metabolic transition and its potential inertia. In this article, we present a long-term global material flow dataset covering material extraction, trade, and consumption of 177 individual countries between 1950 and 2010. We trace patterns and trends in material flows for six major geographic and economic country groupings and world regions (Western Industrial, the (Former) Soviet Union and its allies, Asia, the Middle East and Northern Africa, Latin America and the Caribbean, and Sub-Saharan Africa) as well as their contribution to the emergence of a global metabolic profile during a period of rapid industrialization and globalization. Global average material use increased from 5.0 to 10.3 tons per capita and year (t/cap/a) between 1950 and 2010. Regional metabolic rates range from 4.5 t/cap/a in Sub-Saharan Africa to 14.8 t/cap/a in the Western Industrial grouping. While we can observe a stabilization of the industrial metabolic profile composed of relatively equal shares of biomass, fossil energy carriers, and construction minerals, we note differences in the degree to which other regions are gravitating toward a similar form of material use. Since 2000, Asia has overtaken the Western Industrial grouping in terms of its share in global resource use although not in terms of its per capita material consumption. We find that at a sub-global level, the roles of the world regions have changed. There are, however, no signs yet that this will lead to stabilization or even a reduction of global resource use.  相似文献   

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In addition to lower carbon dioxide emissions, policies to reduce fossil fuel combustion can yield substantial air quality co-benefits via reduced emissions of co-pollutants such as particulate matter and air toxics. If co-pollutant intensity (the ratio of co-pollutant impacts to carbon dioxide emissions) varies across pollution sources, efficient policy design would seek greater emissions reductions where co-benefits are higher. The distribution of co-benefits also raises issues of environmental equity. This paper presents evidence on intersectoral, intrasectoral and spatial variations in co-pollutant intensity of industrial point sources in the United States, and discusses options for integrating co-benefits into climate policy design to advance efficiency and equity.  相似文献   

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In this paper, anomalies of freezing of the European Russia’s rivers in 2006–2007 are considered. Multiyear observation data are used for analysing of trends in time series, which express terms of the first floating ice appearance in the European territory of Russia. It is shown that, in the end of the 20th and beginning of 21st centuries, a tendency of later freezing of rivers in this territory was detected. Linear equations that describe temporal trends were obtained for various rivers. Three variants of terms of the first floating ice appearance until 2020 were computed in accordance with the basic climatic scenarios. It was shown that changes in the climatologic norms are significant for all the scenarios. In comparison with the present values, future changes in the norms can reach 5 through 15 days.  相似文献   

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The European Union (EU) has proposed in its Resource-efficiency roadmap a ‘dashboard of indicators’ consisting of four headline indicators for carbon, water, land and materials. The EU recognizes the need to use a consumption-based (or ‘footprint’) perspective to capture the global dimension of resources and their impacts. In this paper, we analyse how the EU’s footprints compare to those of other nations, to what extent the EU and other major economies of the world rely on embodied resource imports, and what the implications are for policy making based on this comparison. This study is the first comprehensive multi-indicator comparison of all four policy relevant indicators, and uses a single consistent global Multi-Regional Input Output (MRIO) database with a unique and high level of product detail across countries. We find that Europe is the only region in the world that relies on net embodied imports for all indicators considered. We further find that the powerful economies of China and others in the Asia-Pacific already dominate global resource consumption from a footprint perspective, while they still haven’t reached the prosperity of developed countries. Competition for resources is hence likely to increase, making Europe even more vulnerable. A hot spot analysis suggests that final consumption of food, transport and housing are priorities for reduction efforts along the life cycle. Further, countries with a similar Human Development Index can have very different footprints, pointing at societal organisation at macro-level as option for improvement. This points at options for countries for lowering their footprint, becoming less dependent on embodied imports, while maintaining a high quality of life.  相似文献   

14.
The Sundarbans mangrove ecosystem, shared by India and Bangladesh, is recognized as a global priority for biodiversity conservation. Sea level rise, due to climate change, threatens the long term persistence of the Sundarbans forests and its biodiversity. Among the forests’ biota is the only tiger (Panthera tigris) population in the world adapted for life in mangrove forests. Prior predictions on the impacts of sea level rise on the Sundarbans have been hampered by coarse elevation data in this low-lying region, where every centimeter counts. Using high resolution elevation data, we estimate that with a 28 cm rise above 2000 sea levels, remaining tiger habitat in Bangladesh’s Sundarbans would decline by 96% and the number of breeding individuals would be reduced to less than 20. Assuming current sea level rise predictions and local conditions do not change, a 28 cm sea level rise is likely to occur in the next 50–90 years. If actions to both limit green house gas emissions and increase resilience of the Sundarbans are not initiated soon, the tigers of the Sundarbans may join the Arctic’s polar bears (Ursus maritimus) as early victims of climate change-induced habitat loss.  相似文献   

15.
Many difficulties have arisen from top-down approaches to the design and implementation of global environmental initiatives. The concept of translation and other analytical features of Actor-Network Theory (ANT) can offer a way of conceptualising these difficulties and their practical effects. By translation, we refer to what happens in-between the formulation of international goals and the results of implementation, and more specifically, relations and negotiations within this broader process. We examine several aspects of translation in the case of Reducing Emissions from Deforestation and Forest Degradation (REDD+), a prominent global environmental initiative. Using an ethnographic approach, we explore local responses in Central Kalimantan province, Indonesia, to REDD+ ideas and goals that originate at international and national levels. Following selection in 2010 as the official REDD+ pilot province, Central Kalimantan became a site for the convergence of actors and projects with varied sources of funding. The study identifies a central tension that emerged between an initial vision of Central Kalimantan as a pioneer, and local concerns about being used as an experimental subject or ‘guinea pig’ for the testing of externally designed schemes. Results show that greater flexibility in the design of programs and initiatives is needed, to provide space for local inputs. Implementation should pay attention to how local actors are included in planning processes that inform decision-making at higher jurisdictional levels. To bring about intended changes in land use, programs like REDD+ need to extend beyond a focus on short-term projects and targets, to instead emphasise long-term investments and forms of collective action that support learning.  相似文献   

16.
We discovered an error in the computer code generating the simulation results in section 5 of Auffhammer and Aroonruengsawat (Clim Chang 109(Supplement 1):191–210, 2011). While four out of five main findings are unaffected, the simulated impacts of climate change on annual residential electricity consumption are an order of magnitude smaller, which is consistent with findings in the previous literature.  相似文献   

17.
In early policy work, climate engineering is often described as a global public good. This paper argues that the paradigm example of geoengineering—stratospheric sulfate injection (hereafter ‘SSI’)—does not fit the canonical technical definition of a global public good, and that more relaxed versions are unhelpful. More importantly, it claims that, regardless of the technicalities, the public good framing is seriously misleading, in part because it arbitrarily marginalizes ethical concerns. Both points suggest that more clarity is needed about the aims of geoengineering policy—and especially governance—and that this requires special attention to ethics.  相似文献   

18.
China is home to nearly half of the world’s 50,000 large dams, which provide irrigation, flood protection, and hydroelectricity. Most of these projects involve substantial population displacement, which can disrupt social capital, the webs of interdependence and support that community members maintain with one another through relationships of trust and reciprocity. We use new empirical evidence to examine the association between dam-induced displacement and social capital in China and interpret our findings in the context of social–ecological resilience theory. Our focus is on agricultural households on the Upper Mekong River, where four large hydropower dams have been constructed over the past twenty years.Our broad finding is that resettlement is associated with diminished social capital, as measured by two key indicators: inter-household exchange of financial resources, and inter-household exchange of agricultural labor. These effects differ across the four dam sites in the study based on local economic conditions and changes in resettlement policy. We find that population resettlement is associated with markedly lower levels of agricultural labor exchange. In an economically under-developed setting, this reduces the depth and breadth of social support that agricultural households rely on to produce crops for subsistence and income. This in turn diminishes social–ecological resilience because social capital is a key factor that helps agricultural or resource-dependent communities manage risk and adapt to changes and stressors.We consider the policy implications of our findings in the context of scientific and industry efforts to minimize social harm, promote economic vitality, and improve the sustainability of hydropower as a form of renewable energy.  相似文献   

19.
Economic growth commonly occurs at the expense of environmental quality, but there are exceptions. Here we use satellite data to identify places where exceptional economic growth and exceptional environmental improvement co-occurred between 1990 and 2015. We term as “bright spots of green growth” those spatial clusters with the most cells above the 95th percentile within their world region in both economic growth (as proxied by increase in nighttime lights) and one aspect of environmental improvement (forest area). Because the locations of bright spots are sensitive to methodological choices, we applied two different approaches to identifying bright spots. The two approaches differed in their choice of nighttime lights data (DSMP-OLS in Approach A vs. DSMP-VIIRS composite in Approach B); choice of forest area data (forest cover vs. forest land-use); time period (2000–2010 vs. 1990–2015); and clustering technique (visual inspection vs. HDBSCAN algorithm). We identified the top five bright spots in each of ten world regions using each of two approaches, for a total of 100 global bright spots of green growth. We then tested the extent to which the attributes of bright spots were consistent with four non-mutually exclusive theories of green growth. Of the bright spots we identified, around two-thirds (65% using Approach A; 71% using Approach B) had significantly higher-than-regional-average growth in the share of labor employed in services, consistent with sectoral shift and “tertiarization.” Fewer than half (38%; 46%) had significantly higher growth in income, consistent with the “Environmental Kuznets Curve” theory. Some (54%; 29%) had significantly higher growth in timber plantation area, consistent with “eco-industry”-driven rural development. Few (0%; 10%) had significantly higher growth in protected area coverage, consistent with public policy-induced forest conservation. Our findings suggest sectoral shift toward services, rather than rising income per se, may be a promising pathway for other regions seeking to combine economic growth and environmental improvement.  相似文献   

20.
Obtaining realistic land-surface states for initial and boundary conditions is important for the numerical weather prediction of many atmospheric phenomena. Here we investigate model sensitivity to land use and snow cover for a persistent wintertime cold-air pool in northern Utah during 1–8 January 2011. A Weather Research and Forecast model simulation using the 1993 United States Geological Survey land-use and North American Mesoscale model reanalysis snow-cover datasets is compared to an improved configuration using the modified 2011 National Land Cover Database and a more realistic representation of snow cover. The improved surface specification results in an increase (decrease) in urban land cover (Great Salt Lake surface area), and changes to the snow-cover initialization, depth, extent, and albedo. The results obtained from the model simulations are compared to observations collected during the Persistent Cold-Air Pool Study. The changes in land use and snow cover and the resulting impacts on the surface albedo and surface heat fluxes contributed to near-surface air temperature increases of 1–\(2\,^{\circ }\hbox {C}\) in urban areas and decreases of 2–\(4\,^{\circ }\hbox {C}\) in areas surrounding the Great Salt Lake. Although wind speeds in the boundary layer were overestimated in both simulations, shallow thermally-driven and terrain-forced flows were generally lessened in intensity and breadth in response to the decreased areal extent of the Great Salt Lake and increases in the urban footprint.  相似文献   

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