The start of the Ediacaran period is defined by one of the most severe climate change events recorded in Earth history—the recov- ery from the Marinoan ‘snowball’ ice age, ,635 Myr ago (ref. 1). Marinoan glacial-marine deposits occur at equatorial palaeolati- tudes2, and are sharply overlain by a thin interval of carbonate that preserves marine carbon and sulphur isotopic excursions of about 25 and 115 parts per thousand, respectively3–5; these deposits are thought to record widespread oceanic carbonate precipitation during postglacial sea level rise1,3,4. This abrupt transition records a climate system in profound disequilibrium3,6 and contrasts shar- ply with the cyclical stratigraphic signal imparted by the balanced feedbacks modulating Phanerozoic deglaciation. Hypotheses accounting for the abruptness of deglaciation include ice albedo feedback3, deep-ocean out-gassing during post-glacial oceanic overturn7 or methane hydrate destabilization8–10. Here we report the broadest range of oxygen isotope values yet measured in mar- ine sediments (225% to 112%) in methane seeps in Marinoan deglacial sediments underlying the cap carbonate. This range of values is likely to be the result of mixing between ice-sheet-derived meteoric waters and clathrate-derived fluids during the flushing and destabilization of a clathrate field by glacial meltwater. The equatorial palaeolatitude implies a highly volatile shelf permafrost pool that is an order of magnitude larger than that of the present day. A pool of this size could have provided a massive biogeochem- ical feedback capable of triggering deglaciation and accounting for the global postglacial marine carbon and sulphur isotopic excur- sions, abrupt unidirectional warming, cap carbonate deposition, and a marine oxygen crisis. Our findings suggest that methane released from low-latitude permafrost clathrates therefore acted as a trigger and/or strong positive feedback for deglaciation and warming. Methane hydrate destabilization is increasingly suspected as an important positive feedback to climate change11–13 that coincides with critical boundaries in the geological record14,15 and may represent one particularly important mechanism active during conditions of strong climate forcing.
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Over the past decade, a growing body of research has been conducted on the human dimensions of wildland fire. Building on a relatively small number of foundational studies, this research now addresses a wide range of topics including mitigation activities on private lands, fuels reduction treatments on public land, community impacts and resident behaviors during fire, acceptance of approaches to postfire restoration and recovery, and fire management policy and decisionmaking. As this research has matured, there has been a recognition of the need to examine the full body of resulting literature to synthesize disparate findings and identify lessons learned across studies. These lessons can then be applied to fostering fire-adapted communities—those communities that understand their risk and have taken action to mitigate their vulnerability and increase resilience.
This compendium of social science research findings related to fire-adapted communities has resulted from a project funded by the Joint Fire Science Program (JFSP). As part of these efforts, the research team reviewed more than 200 publications of research results. Then the team convened a workshop with 16 scientists with extensive experience in the human dimensions of fire management issues. Workshop participants evaluated collective findings and discussed their application to support fire management activities. In addition to this compendium, project outputs were: 1) a synthesis of published literature specific to eight management questions identified by the JFSP, 2) a list of future research needs, 3) a bibliography, including abstracts, with accompanying subject area guide, and 4) a video featuring the experiences of agency personnel and community leaders in successful collaborative fire planning settings. This video is accompanied by a field guide for use by agency managers to more effectively participate in building fire-safe communities.
In the sections that follow, we describe our approach to completing this review and present key findings from the literature. Our discussion is organized around five major topical areas: 1) homeowner/community mitigation, 2) public acceptance of fuels treatments on public lands, 3) homeowner actions during a fire, 4) postfire response and recovery, and 5) wildland fire policy and planning. The compendium concludes with a presentation of management implications and a bibliography of all material in this review.
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