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The outcome is in the assumptions: analyzing the effects on atmospheric CO2 levels of increased use of bioenergy from forest biomass
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Recently, several studies have quantified the effects on atmospheric CO2 concentration of an increased harvest level in forests. Although these studies agreed in their estimates of forest productivity, their conclusions were contradictory. This study tested the effect of four assumptions by which those papers differed. These assump- tions regard (1) whether a single or a set of repeated harvests were considered, (2) at what stage in stand growth harvest takes place, (3) how the baseline is constructed, and (4) whether a carbon-cycle model is applied. A main finding was that current and future increase in the use of bioenergy should be studied considering a series of repeated harvests. Moreover, the time of harvest should be determined based on economical principles, thus taking place before stand growth culminates, which has implications for the design of the baseline scenario. When the most realistic assumptions are used and a carbon-cycle model is applied, an increased harvest level in forests leads to a permanent increase in atmospheric CO2 concentration.
Keywords: atmosphere, bioenergy, carbon, climate change, Faustmann, impulse response functions
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The payoff of conservation investments in tropical countryside
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The future of biodiversity and ecosystem services hinges on har- monizing agricultural production and conservation, yet there is no planning algorithm for predicting the efficacy of conservation investments in farmland. We present a conservation planning framework for countryside (working agricultural landscapes) that calculates the production and conservation benefits to the current baseline of incremental investments. Our framework is analogous to the use of reserve design algorithms. Unlike much countryside modeling, our framework is designed for application in data- limited contexts, which are prevalent. We apply our framework to quantify the payoff for Costa Rican birds of changing farm plot and border vegetation. We show that installing windbreaks of native vegetation enhances both bird diversity and farm income, espe- cially when complementing certain crop types. We make predic- tions that differ from those of approaches currently applied to agri-environment planning,: e.g., although habitat with trees has lower local species richness than farm plot habitats (1– 44% lower), replacing any plot habitat with trees should boost regional rich- ness considerably. Our planning framework reveals the small, targeted changes on farms that can make big differences for biodiversity.
biodiversity conservation planning countryside biogeography ecological-economic models matrix
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The Perfect Ocean for Drought
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The 1998 –2002 droughts spanning the United States, southern Europe, and South- west Asia were linked through a common oceanic influence. Cold sea surface temperatures (SSTs) in the eastern tropical Pacific and warm SSTs in the western tropical Pacific and Indian oceans were remarkably persistent during this period. Climate models show that the climate signals forced separately by these regions acted synergistically, each contributing to widespread mid-latitude drying: an ideal scenario for spatially expansive, synchronized drought. The warmth of the Indian and west Pacific oceans was unprecedented and consistent with greenhouse gas forcing. Some implications are drawn for future drought.
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The physical basis for increases in precipitation extremes in simulations of 21st-century climate change
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Global warming is expected to lead to a large increase in atmospheric water vapor content and to changes in the hydrological cycle, which include an intensification of precipitation extremes. The intensity of precipitation extremes is widely held to increase proportionately to the increase in atmospheric water vapor content. Here, we show that this is not the case in 21st-century climate change scenarios simulated with climate models. In the tropics, precipitation extremes are not simulated reliably and do not change consistently among climate models; in the extratropics, they consistently increase more slowly than atmospheric water vapor content. We give a physical basis for how precipitation extremes change with climate and show that their changes depend on changes in the moist-adiabatic temperature lapse rate, in the upward velocity, and in the temperature when precipitation ex- tremes occur. For the tropics, the theory suggests that improving the simulation of upward velocities in climate models is essential for improving predictions of precipitation extremes; for the extra- tropics, agreement with theory and the consistency among climate models increase confidence in the robustness of predictions of precipitation extremes under climate change.
global warming hydrological cycle rainfall extreme events
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The potential for behavioral thermoregulation to buffer ‘‘cold-blooded’’ animals against climate warming
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Increasing concern about the impacts of global warming on biodi- versity has stimulated extensive discussion, but methods to trans- late broad-scale shifts in climate into direct impacts on living animals remain simplistic. A key missing element from models of climatic change impacts on animals is the buffering influence of behavioral thermoregulation. Here, we show how behavioral and mass/energy balance models can be combined with spatial data on climate, topography, and vegetation to predict impacts of in- creased air temperature on thermoregulating ectotherms such as reptiles and insects (a large portion of global biodiversity). We show that for most ‘‘cold-blooded’’ terrestrial animals, the primary thermal challenge is not to attain high body temperatures (al- though this is important in temperate environments) but to stay cool (particularly in tropical and desert areas, where ectotherm biodiversity is greatest). The impact of climate warming on ther- moregulating ectotherms will depend critically on how changes in vegetation cover alter the availability of shade as well as the animals’ capacities to alter their seasonal timing of activity and reproduction. Warmer environments also may increase mainte- nance energy costs while simultaneously constraining activity time, putting pressure on mass and energy budgets. Energy- and mass-balance models provide a general method to integrate the complexity of these direct interactions between organisms and climate into spatial predictions of the impact of climate change on biodiversity. This methodology allows quantitative organism- and habitat-specific assessments of climate change impacts.
Australia biophysical model climate change terrestrial ectotherm GIS
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The potential transient dynamics of forests in New England under historical and projected future climate change
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Projections of vegetation distribution that incorporate the transient responses of vegetation to climate change are likely to be more efficacious than those that assume an equilibrium between climate and vegetation. We examine the non-equilibrium dynamics of a temperate forest region under historic and projected future climate change using the dynamic ecosystem model LPJ-GUESS. We parameterized LPJ-GUESS for the New England region of the United Sates utilizing eight forest cover types that comprise the regionally dominant species. We developed a set of climate data at a monthly-step and a 30-arc second spatial resolution to run the model. These datasets consist of past climate observations for the period 1901–2006 and three general circulation model projections for the period 2007–2099. Our baseline (1971–2000) simulation reproduces the distribution of forest types in our study region as compared to the National Land Cover Data 2001 (Kappa statistic00.54). Under historic and nine future climate change scenarios, maple-beech-basswood, oaks and aspen- birch were modeled to move upslope at an estimated rate of 0.2, 0.3 and 0.5 myr−1 from 1901 to 2006, and continued this trend at an accelerated rate of around 0.5, 0.9 and 1.7 myr−1 from 2007 to 2099. Spruce-fir and white pine-cedar were modeled to contract to mountain ranges and cooler regions of our study region under projected future climate change scenarios. By the end of the 21st century, 60% of New England is projected to be dominated by oaks relative to 21% at the beginning of the 21st century, while northern New England is modeled to be dominated by aspen-birch. In mid and central New England, maple-beech-basswood, yellow birch-elm and hickories co-occur and form novel species associations. In addition to warming-induced northward and upslope shifts, climate change causes more complex changes in our simulations, such as reversed conversions between forest types that currently share similar bioclimatic ranges. These results underline the importance of considering community interactions and transient dynamics in modeling studies of climate change impacts on forest ecosystems.
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The Present and Future Possibilities of Landscape Scale Conservation: AppLCC Ethnographic Study Video of Presentation
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The Landscape Conservation Cooperative (LCC) program was created under a secretarial order to develop regional conservation partnerships – under the Department of the Interior – that aimed to coordinate regional conservation planning in response to climate change impacts. Because they were partner-driven efforts, each of the 22 LCCs followed a distinct trajectory and implemented diverse projects, meaning that there is value in exploring how specific LCCs, such as the AppLCC, approached regional conservation. This study assesses the successes, limitations, and impacts of the AppLCC, with the aim of providing insights for future regional conservation partnership.
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Integrating Cultural Resource Preservation at a Landscape Level
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Cultural Resources Fellowship
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The Present and Future Possibilities of Landscape Scale Conservation: AppLCC Ethnographic Study Video of Presentation
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The Landscape Conservation Cooperative (LCC) program was created under a secretarial order to develop regional conservation partnerships – under the Department of the Interior – that aimed to coordinate regional conservation planning in response to climate change impacts. Because they were partner-driven efforts, each of the 22 LCCs followed a distinct trajectory and implemented diverse projects, meaning that there is value in exploring how specific LCCs, such as the AppLCC, approached regional conservation. This study assesses the successes, limitations, and impacts of the AppLCC, with the aim of providing insights for future regional conservation partnership.
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Integrating Cultural Resource Preservation at a Landscape Level
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Cultural Resources Fellowship
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The Problem of Perfection.pdf
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NIC-PEK
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The proportionality of global warming to cumulative carbon emissions
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The global temperature response to increasing atmospheric CO2 is often quantified by metrics such as equilibrium climate sensitivity and transient climate response1. These approaches, however, do not account for carbon cycle feedbacks and therefore do not fully represent the net response of the Earth system to anthropogenic CO2 emissions. Climate–carbon modelling experiments have shown that: (1) the warming per unit CO2 emitted does not depend on the background CO2 concentration2; (2) the total allowable emissions for climate stabilization do not depend on the timing of those emissions3–5; and (3) the temperature response to a pulse of CO2 is approximately constant on timescales of decades to centuries3,6–8. Here we generalize these results and show that the carbon–climate response (CCR), defined as the ratio of temper- ature change to cumulative carbon emissions, is approximately independent of both the atmospheric CO2 concentration and its rate of change on these timescales. From observational constraints, we estimate CCR to be in the range 1.0–2.1 6C per trillion tonnes of carbon (TtC) emitted (5th to 95th percentiles), consistent with twenty-first-century CCR values simulated by climate–carbon models. Uncertainty in land-use CO2 emissions and aerosol forcing, however, means that higher observationally constrained values cannot be excluded. The CCR, when evaluated from climate– carbon models under idealized conditions, represents a simple yet robust metric for comparing models, which aggregates both climate feedbacks and carbon cycle feedbacks. CCR is also likely to be a useful concept for climate change mitigation and policy; by combining the uncertainties associated with climate sensitivity, carbon sinks and climate–carbon feedbacks into a single quantity, the CCR allows CO2-induced global mean temperature change to be inferred directly from cumulative carbon emissions.
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