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Uihlein, Bill
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UMRCC 1988.pdf
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UMRCC 1989 Chairmans Letter.pdf
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TUD-VAN
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UMRCC 1989.pdf
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UMRCC 1990.pdf
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TUD-VAN
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Unburnable Carbon – Are the world’s financial markets carrying a carbon bubble?
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The Carbon Tracker initiative is a new way of looking at the carbon emissions
problem. It is focused on the fossil fuel reserves held by publically listed
companies and the way they are valued and assessed by markets. Currently
financial markets have an unlimited capacity to treat fossil fuel reserves
as assets. As governments move to control carbon emissions, this market
failure is creating systemic risks for institutional investors, notably the
threat of fossil fuel assets becoming stranded as the shift to a low-carbon
economy accelerates.
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Climate Science Documents
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Understanding Interaction Effects of Climate Change and Fire Management on Bird Distributions through Combined Process and Habitat Models
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Avian conservation efforts must account for changes in vegetation composition and structure associated with climate change. We modeled vegetation change and the probability of occurrence of birds to project changes in winter bird distributions associated with climate change and fire management in the northern Chihuahuan Desert (southwestern U.S.A.). We simulated vegetation change in a process-based model (Landscape and Fire Simulator) in which anticipated climate change was associated with doubling of current atmospheric carbon dioxide over the next 50 years. We estimated the relative probability of bird occurrence on the basis of statistical models derived from field observations of birds and data on vegetation type, topography, and roads. We selected 3 focal species, Scaled Quail ( Callipepla squamata), Loggerhead Shrike ( Lanius ludovicianus), and Rock Wren ( Salpinctes obsoletus), that had a range of probabilities of occurrence for our study area. Our simulations projected increases in relative probability of bird occurrence in shrubland and decreases in grassland and Yucca spp. and ocotillo ( Fouquieria splendens) vegetation. Generally, the relative probability of occurrence of all 3 species was highest in shrubland because leaf-area index values were lower in shrubland. This high probability of occurrence likely is related to the species’ use of open vegetation for foraging. Fire suppression had little effect on projected vegetation composition because as climate changed there was less fuel and burned area. Our results show that if future water limits on plant type are considered, models that incorporate spatial data may suggest how and where different species of birds may respond to vegetation changes.
Keywords: climate change, conservation planning, desert birds, ecosystem modeling, fire suppression
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Understanding Soil Time
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Efforts to maintain soils in a sustainable
manner are complicated by interactions among
soil components that respond to perturbation
at vastly different rates.
VOL 321 SCIENCE
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Understanding strategies for seed dispersal by wind under contrasting atmospheric conditions
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Traits associated with seed dispersal vary tremendously among sympatric wind-dispersed plants. We used two contrasting tropical tree species, seed traps, micrometeorology, and a mechanistic model to evaluate how variation in four key traits affects seed dispersal by wind. The conceptual framework of movement ecology, wherein external factors (wind) interact with internal factors (plant traits) that enable movement and determine when and where movement occurs, fully captures the variable inputs and outputs of wind dispersal models and informs their interpretation. We used model calculations to evaluate the spatial pattern of dispersed seeds for the 16 factorial combinations of four traits. The study species differed dramatically in traits related to the timing of seed release, and a strong species by season interaction affected most aspects of the spatial pattern of dispersed seeds. A rich interplay among plant traits and seasonal differences in atmo- spheric conditions caused this interaction. Several of the same plant traits are crucial for both seed dispersal and other aspects of life history variation. Observed traits that limit dispersal are likely to be constrained by their life history consequences.
atmospheric turbulence conditional seed release Coupled Eulerian-Lagrangian closure (CELC) model long distance dispersal tropical forest
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Understanding the changing hydrologic regime and storage requirements in the Upper Colorado River basin
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The changing hydrologic regime of the Upper Colorado River Basin presents a daunting challenge for water resources management. A major source of concern is that of ascertaining the nature of runoff variability and re- calibrating the systemic management and planning based on a more reliable envelope of water supply variations to meet societal needs. In this letter, we examine the long-term variability and change in the Upper Colorado annual runoff volume—quantified as shifts in the mean, interannual variability, and persistence—in a recent tree-ring based reconstruction extending back to 762AD. A simple model for reservoir storage requirement shows sensitivity to the changing hydrologic regime, with episodes of abrupt shifts toward significantly higher storage requirements, often not readily evident in runoff statistics. The results also suggest that benchmarking of climate models for regional water resources assessment should focus on the runoff statistics that are most relevant for storage requirement computations.
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