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ABSTRACT. Consumption and assi~mlation rates of marine zooplankton feeding on large, abundant aggregates, known as marine snow, were measured for the first time. Two common zooplankton species, the euphausiid Euphausia pacifica and the copepod Calanuspacificus, consumed diverse types of field-collected marine snow, including diatom flocs, abandoned larvacean houses, and dinoflagellate aggregates, regardless of their composition, C:N ratio, age, or the availability of alternate dispersed food. Ingest~on rates of aggregates by E. pacifica increased with Increasing marine snow concentration, although in situ concentrations of aggregates were not sufficient to elic~t a maximum ingestion rate Ingestion rates of aggregates by E. pacifica at higher aggregate concentrations were from 9 to 15 pg C euphausiid-' h-'. Assimilation efficiencies of euphausiids grazing on marine snow were 83 % (dinoflagellate snow) and 64 to 75% (diatom/larvacean house snow) These results indicate that marine snow can be an ~mportant food source for marine zooplankton and that consumption of large aggregates 1s likely to play a role in the cycling of carbon and the structure of food webs In the pelagic zone of the ocean.

Recent reports and scholarship suggest that adapting to current climate variability may represent a 'no regrets' strategy for adapting to climate change. Addressing 'adaptation deficits' and other approaches that target existing vulnerabilities are helpful for responding to current climate variability, but we argue that they may not be sufficient for adapting to climate change. Through a review and unique synthesis of the natural hazards and climate adaptation literatures, we identify why the dynamics of vulnerability matter for adaptation efforts. We draw on vulnerability theory and the natural hazards and climate adaptation literatures to outline how adaptation to climate variability, combined with the shifting societal landscape can sometimes lead to unintended consequences and increased vulnerability. Moreover, we argue that public perceptions of risk associated with current climate variability do not necessarily position communities to adapt to the impacts from climate change. We suggest that decision makers faced with adapting to climate change must consider the dynamics of vulnerability in a connected system-how choices made in one part of the system might impact other valued outcomes or even create new vulnerabilities. We conclude by suggesting the need for greater engagement with various publics on the tradeoffs involved in adaptation action and for improving communication about the complicated nature of the dynamics of vulnerability.

Despite hazard mitigation efforts and scientific and technological advances, extreme weather events continue to cause substantial losses. The impacts of extreme weather result from complex interactions among physical and human systems across spatial and temporal scales. This article synthesizes current interdisciplinary knowledge about extreme weather, including temperature extremes (heat and cold waves), precipitation extremes (including floods and droughts), and storms and severe weather (including tropical cyclones). We discuss hydrometeorological aspects of extreme weather; projections of changes in extremes with anthropogenic climate change; and how social vulnerability, coping, and adaptation shape the societal impacts of extreme weather. We find four critical gaps where work is needed to improve outcomes of extreme weather: (a) reducing vulnerability; (b) enhancing adaptive capacity, including decision-making flexibility; (c) improving the usability of scientific information in decision making, and (d) understanding and addressing local causes of harm through participatory, community-based efforts formulated within the larger policy context. 1 Click here for quick links to Annual Reviews content online, including: • Other articles in this volume • Top cited articles • Top downloaded articles • Our comprehensive search Further ANNUAL REVIEWS Extreme weather: weather conditions and weather-related events that are rare at a particular location and time or can cause significant impacts Vulnerability: the susceptibility of people or systems to damage or harm Climate change mitigation: human intervention to reduce emissions and/or concentrations of carbon dioxide and other greenhouse gases Adaptation: long-term or fundamental changes people make to systematically reduce potential harm (or take advantage of opportunities) from changing weather stressors

ABSTRACT. Climate change and its associated consequences pose an increasing risk to public lands in the western United States. High-level mandates currently require federal agencies to begin planning for adaptation, but the extent to which these mandates have resulted in policies being implemented that affect on the ground practices is unclear. To examine the status of adaptation efforts, we conducted an original survey and semistructured interviews with land managers from the four major federal land management agencies in the U.S. states of Colorado, Utah, and Wyoming. The survey was designed to examine current planning for adaptation on public lands and how it differs from prior planning, the major challenges facing land managers in this region, the major barriers preventing managers from planning for adaptation, and the major hurdles associated with implementing adaptation plans. Our results show that some adaptation planning is currently taking place, but that few adaptation projects have made it to the implementation phase. Overall, respondents considered lack of information at relevant scales, budget constraints, lack of specific agency direction, and lack of useful information to be the most common barriers to adaption planning. Budget constraints, lack of perceived importance to the public, and lack of public awareness or demand to take action were reported to be the biggest hurdles to implementation of adaptation projects. Agencies showed differing levels of adaptation activity, and reported different barriers to adaptation and hurdles to implementation. Reasons for the differences and implications for future research and policy are discussed.

The Paris Agreement established a global goal on adaptation and invites parties to review the effectiveness of adaptation actions. However, the measurement of adaptation success remains elusive. Focusing on the capabilities of households and governments to pursue a range of adaptation futures provides a more robust foundation. The Paris Agreement established a global goal on adaptation (Article 7, para. 1) and invites Parties to "review the adequacy and effectiveness of adaptation" in a global stocktake (Article 7, para 14c). However, creating universally applicable measures of adaptation success remains elusive given that most adaptation projects are implemented at the local level, and start from wildly differing baseline conditions. Further, the adaptation process is never truly "finished" in a changing, evolving climate 1. Berrang-Ford et al. 2 propose tracking government adaptation policy instruments as a way to assess progress. However, these and other approaches do not address what constitutes "success", focusing instead on government planning, or how vulnerability is changing-leaving open the question of vulnerability of whom, This comment evolved from a special session on adaptation success convened by the authors at Adaptation Futures 2018, the 5th International Climate Change Adaptation Conference in Cape Town. We thank the over 100 session participants from around the world, including participants from government agencies, donors, non-governmental organizations, students, humanitarian agencies, academics, policy-makers and members of civil society.