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1.5°C or 2°C: a conduit’s view from the science-policy interface at COP20 in Lima, Peru
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An average global 2°C warming compared to pre-industrial times is commonly understood as the most important target in climate policy negotiations. It is a temperature target indicative of a fiercely debated threshold between what some consider acceptable warming and warming that implies dangerous anthropogenic interference with the climate system and hence to be avoided. Although this 2°C target has been officially endorsed as scientifically sound and justified in the Copenhagen Report issued by the 15th Conference of the Parties (COP) of the United Nations Framework Convention on Climate Change (UNFCCC) in 2009, the large majority of countries (over two-thirds) that have signed and ratified the UNFCCC strongly object to this target as the core of the long-term goal of keeping temperatures below a certain danger level. Instead, they promote a 1.5°C target as a more adequate limit
for dangerous interference. At COP16 in Cancun, parties to the convention recognized the need to consider strengthening the long-term global goal in the so-called 2013–2015 Review, given improved scientific knowledge, including the possible adoption of the 1.5°C target. In this perspective piece, I examine the discussions of a structured expert dialogue (SED) between selected Intergovernmental Panel on Climate Change (IPCC) authors, myself included, and parties to the convention to assess the adequacy of the long-term goal. I pay particular attention to the uneven geographies and power differentials that lay behind the ongoing political debate regarding an adequate target for protecting ecosystems, food security, and sustainable development.
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Climate Science Documents
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2012 was Warmest and Second Most Extreme Year on Record for the Contiguous U.S.
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2012 marked the warmest year on record for the contiguous United States with the year consisting of a record warm spring, second warmest summer, fourth warmest winter and a warmer-than-average autumn.
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News & Events
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A drought-induced pervasive increase in tree mortality across Canada’s boreal forests
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Drought-induced tree mortality is expected to increase worldwide under projected future climate changes (1–4). The Canadian boreal forests, which occupy about 30% of the boreal forests worldwide and 77% of Canada’s total forested land, play a critical role in the albedo of Earth’s surface (5) and in its global carbon budget (6). Many of the previously reported regional-scale impacts of drought on tree mortality have affected low- and middle-latitude tropical regions (2) and the temperate forests of the western United States (3), but no study has examined high-latitude boreal regions with multiple species at a regional scale using long-term forest permanent sampling plots (7–9). Here, we estimated tree mortality in natural stands throughout Canada’s boreal forests using data from the permanent sampling plots and statistical models. We found that tree mortality rates increased by an overall average of 4.7%yr−1 from 1963 to 2008, with higher mortality rate increases in western regions than in eastern regions (about 4.9 and 1.9% yr−1 ,respectively).The water stress created by regional drought may be the dominant contributor to these widespread increases in tree mortality rates across tree species, sizes, elevations, longitudes and latitudes. Western Canada seems to have been more sensitive to drought than eastern Canada.
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Climate Science Documents
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A globally coherent fingerprint of climate change impacts across natural systems
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Causal attribution of recent biological trends to climate change is complicated because non-climatic influences dominate local, short-term biological changes. Any underlying signal from climate change is likely to be revealed by analyses that seek systematic trends across diverse species and geographic regions; however, debates within the Intergovernmental Panel on Climate Change (IPCC) reveal several definitions of a ‘systematic trend’. Here, we explore these differences, apply diverse analyses to more than 1,700 species, and show that recent biological trends match climate change predictions. Global meta-analyses documented significant range shifts averaging 6.1 km per decade towards the poles (or metres per decade upward), and significant mean advancement of spring events by 2.3 days per decade. We define a diagnostic fingerprint of temporal and spatial ‘sign-switching’ responses uniquely predicted by twentieth century climate trends. Among appropriate long-term/large-scale/multi-species data sets, this diagnostic fingerprint was found for 279 species. This suite of analyses generates ‘very high confidence’ (as laid down by the IPCC) that climate change is already affecting living systems.
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Climate Science Documents
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A large source of low-volatility secondary organic aerosol
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Forests emit large quantities of volatile organic compounds (VOCs) to the atmosphere. Their condensable oxidation products can form secondary organic aerosol, a significant and ubiquitous component of atmospheric aerosol 1,2, which is known to affect the Earth’s radiation balance by scattering solar radiation and by acting as cloud condensation nuclei 3. The quantitative assessment of such climate effects remains hampered by a number of factors, including an incom- plete understanding of how biogenic VOCs contribute to the formation of atmospheric secondary organic aerosol. The growth of newly formed particles from sizes of less than three nanometres up to the sizes of cloud condensation nuclei (about one hundred nanometres) in many continental ecosystems requires abundant, essentially non- volatile organic vapours4–6, but the sources and compositions of such vapours remain unknown. Here we investigate the oxidation of VOCs, in particular the terpene a-pinene, under atmospherically relevant conditions in chamber experiments. We find that a direct pathway leads from several biogenic VOCs, such as monoterpenes, to the for- mation of large amounts of extremely low-volatility vapours. These vapours form at significant mass yield in the gas phase and condense irreversibly onto aerosol surfaces to produce secondary organic aero- sol, helping to explain the discrepancy between the observed atmo- spheric burden of secondary organic aerosol and that reported by many model studies2. We further demonstrate how these low-volatility vapours can enhance, or even dominate, the formation and growth of aerosol particles over forested regions, providing a missing link between biogenic VOCs and their conversion to aerosol particles. Our findings could help to improve assessments of biosphere–aerosol– climate feedback mechanisms 6–8, and the air quality and climate effects of biogenic emissions generally.
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Climate Science Documents
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A Review of Climate-Change Adaptation Strategies for Wildlife Management and Biodiversity Conservation
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We reviewed the literature and climate- change adaptation plans that have been developed in United States, Canada, England, Mexico, and South Africa and finding 16 general adaptation strategies that relate directly to the conservation of biological diversity. These strategies can be grouped into four broad categories: land and water protection and management; direct species management; monitoring and planning; and law and policy. Tools for implementing these strategies are similar or identical to those already in use by conservationists worldwide (land and water conservation, ecological restoration, agrienvironment schemes, species translocation, captive propagation, monitoring, natural resource planning, and legislation/regulation). Although the review indicates natural resource managers already have many tools that can be used to address climate-change effects, managers will likely need to apply these tools in novel and innovative ways to meet the unprecedented challenges posed by climate change.
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General Resources Holdings
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A Stream Classification System for the Appalachian Landscape Conservation Cooperative
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Unifying state-based stream classifications into a single consistent system, principal investigators at The Nature Conservancy developed a hierarchical classification system and map for stream and river systems for the Appalachian LCC that represents the region’s natural flowing-water aquatic habitats. This river classification information is needed to develop and implement instream flow standards and management recommendations so that environmental flows can become integral to all water management decisions from the onset.
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Research
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Appalachian LCC Coordinator is Panelist at National Conference on Science, Policy and the Environment
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Appalachian LCC Coordinator and Chief Scientist, Dr. Jean Brennan, participated as an invited speaker at the 16th National Conference and Global Forum on Science, Policy and the Environment in Washington DC.
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News & Events
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Assessment and Restoration of Southern Appalachian Brook Trout
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This project will complete an assessment of brook trout in-stream habitat, water quality, and fish distribution information in all Jocassee Gorges streams during the first two years of the project.
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Projects
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Braven Beaty: The Nature Conservancy - Clinch Valley Program
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Braven Beaty discusses his work in the Appalachian region with mussels, the biological importance of the Clinch-Powell River Basin, and how the Appalachian LCC helped to preserve freshwater mussel populations.
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