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Reconstruction of the history of anthropogenic CO2 concentrations in the ocean
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The release of fossil fuel CO2 to the atmosphere by human activity has been implicated as the predominant cause of recent global climate change1. The ocean plays a crucial role in mitigating the effects of this perturbation to the climate system, sequestering 20 to 35 per cent of anthropogenic CO2 emissions2–4. Although much progress has been made in recent years in understanding and quantifying this sink, considerable uncertainties remain as to the distribution of anthropogenic CO2 in the ocean, its rate of uptake over the industrial era, and the relative roles of the ocean and terrestrial biosphere in anthropogenic CO2 sequestration. Here we address these questions by presenting an observationally based reconstruction of the spatially resolved, time-dependent history of anthropogenic carbon in the ocean over the industrial era. Our approach is based on the recognition that the transport of tracers in the ocean can be described by a Green’s function, which we estimate from tracer data using a maximum entropy deconvo- lution technique. Our results indicate that ocean uptake of anthro- pogenic CO2 has increased sharply since the 1950s, with a small decline in the rate of increase in the last few decades. We estimate the inventory and uptake rate of anthropogenic CO2 in 2008 at 140 6 25 Pg C and 2.3 6 0.6 Pg C yr21, respectively. We find that the Southern Ocean is the primary conduit by which this CO2 enters the ocean (contributing over 40 per cent of the anthro- pogenic CO2 inventory in the ocean in 2008). Our results also suggest that the terrestrial biosphere was a source of CO2 until the 1940s, subsequently turning into a sink. Taken over the entire industrial period, and accounting for uncertainties, we estimate that the terrestrial biosphere has been anywhere from neutral to a net source of CO2, contributing up to half as much CO2 as has been taken up by the ocean over the same period.
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Recovery of large carnivores in Europe’s modern human-dominated landscapes
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The conservation of large carnivores is a formidable challenge for biodiversity conservation. Using a data set on the past and current status of brown bears (Ursus arctos), Eurasian lynx (Lynx lynx), gray wolves (Canis lupus), and wolverines (Gulo gulo) in European countries, we show that roughly one-third of mainland Europe hosts at least one large carnivore species, with stable or increasing abundance in most cases in 21st-century records. The reasons for this overall conservation success include protective legislation, supportive public opinion, and a variety of practices making coexistence between large carnivores and people possible. The European situation reveals that large carnivores and people can share the same landscape.
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Reducing Greenhouse Gas Emissions from Deforestation and ForestDegradation: Global Land-Use Implications
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Recent climate talks in Bali have made progress toward action on deforestation and forest degradation
in developing countries, within the anticipated post-Kyoto emissions reduction agreements. As a result
of such action, many forests will be better protected, but some land-use change will be displaced to
other locations. The demonstration phase launched at Bali offers an opportunity to examine potential
outcomes for biodiversity and ecosystem services. Research will be needed into selection of priority
areas for reducing emissions from deforestation and forest degradation to deliver multiple benefits,
on-the-ground methods to best ensure these benefits, and minimization of displaced land-use change
into nontarget countries and ecosystems, including through revised conservation investments
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Reduction in carbon uptake during turn of the century drought in western North America
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Fossil fuel emissions aside, temperate North America is a net sink of carbon dioxide at present1–3. Year-to-year variations in this carbon sink are linked to variations in hydroclimate that affect net ecosystem productivity3,4. The severity and incidence of climatic extremes, including drought, have increased as a result of climate warming5–8. Here, we examine the effect of the turn of the century drought in western North America on carbon uptake in the region, using reanalysis data, remote sensing observations and data from global monitoring networks. We show that the area-integrated strength of the western North American carbon sink declined by 30–298Tg C yr−1 during the 2000–2004 drought. We further document a pronounced drying of the terrestrial biosphere during this period, together with a reduction in river discharge and a loss of cropland productivity. We compare our findings with previous palaeoclimate reconstructions7 and show that the last drought of this magnitude occurred more than 800 years ago. Based on projected changes in precipitation and drought severity, we estimate that the present mid-latitude carbon sink of 177–623 Tg C yr−1 in western North America could disappear by the end of the century.
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Reduction of spring warming over East Asia associated with vegetation feedback
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Over East Asia, surface air temperature displays a significant increasing trend particularly in early months of the year for the period of 1982 – 2000. Warming per decade is strongest in late winter, 1.5°C in February and 1.1°C in March, but is significantly reduced in spring, 0.4°C in April and 0.1°C in May. During the analysis period, the reduced temperature increase from late winter to spring is found to be in contrast with the increased vegetation greenness derived from the satellite-measured leaf area index over the domain. We examined this inverse relationship using two climate model experiments— coupled with and without a dynamic vegetation model. In both experiments, strong warming in winter is relatively well reproduced, but weak warming in spring is observed only in the coupled experiment. Analysis of the surface energy budget indicates that weaker spring warming results from an evaporative cooling effect due to the increased vegetation greenness. Over East Asia, the vegetation-evaporation feedback, therefore, may produce seasonal asymmetry in the warming trend.
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Reeves, Bill
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Reframing Environmental Messages to be Congruent with American Values
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Prior research has explored the relationship between values, attitudes about environmental issues, and pro-environmental behavior. These studies have shown a consistent pattern of results — individuals who value self-transcendent life goals tend to care more about environmental problems, favor environmental protection over economic growth, and engage in more proenvironmental behavior. In contrast, indi- viduals who value self-enhancing life goals tend to hold more egoistic concerns about environmental issues, tend to favor economic growth over environmental protection, and tend to engage in fewer environmental behaviors. Research on American values suggests that overall, people in the U.S. tend to hold strong self-enhancing values. These self- enhancing values have largely been considered incongruous with the values that lead to environmental concern and to environmental behavior. In this paper, we synthesize the past research on the relationship between values and environmen- tal behavior. Lessons from the Biodiversity Project are used to illustrate efforts to create effective value-based environmental messages.
Keywords: values, environmental attitudes, proenvironmental behavior, value-based messages
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REfugia in conservation.pdf
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Refugia: identifying and understanding safe havens for biodiversity under climate change
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Identifying and protecting refugia is a priority for conservation under pro- jected anthropogenic climate change, because of their demonstrated ability to facilitate the survival of biota under adverse conditions. Refugia are habitats that components of biodiversity retreat to, persist in and can potentially expand from under changing environmental conditions. However, the study and discussion of refugia has often been ad hoc and descriptive in nature. We therefore: (1) provide a habitat-based concept of refugia, and (2) evaluate methods for the identification of refugia.
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Regional and Global Impacts of Land Cover Change and Sea Surface Temperature Anomalies
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Model results show that, at the global scale, the physical impacts of LCC on temperature and rainfall are less important than large-scale SST anomalies, particularly those due to ENSO. However, in the regions where the land surface has been altered, the impact of LCC can be equally or more important than the SST forcing patterns in determining the seasonal cycle of the surface water and energy balance. Thus, this work provides a context for the impacts of LCC on climate: namely, strong regional-scale impacts that can sig- nificantly change globally averaged fields but that rarely propagate beyond the disturbed regions. This suggests that proper representation of land cover conditions is essential in the design of climate model experiments, particularly if results are to be used for regional-scale assessments of climate change impacts.
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