The human impact on life on Earth has increased sharply since the 1970s, driven by the demands of a growing population with rising average per capita income. Nature is currently supplying more materials than ever before, but this has come at the high cost of unprecedented global declines in the extent and integrity of ecosystems, distinctness of local ecological communities, abundance and number of wild species, and the number of local domesticated varieties. Such changes reduce vital benefits that people receive from nature and threaten the quality of life of future generations. Both the benefits of an expanding economy and the costs of reducing nature’s benefits are unequally distributed. The fabric of life on which we all depend—nature and its contributions to people—is unravelling rapidly. Despite the severity of the threats and lack of enough progress in tackling them to date, opportunities exist to change future trajectories through transformative action. Such action must begin immediately, however, and address the root economic, social, and technological causes of nature’s deterioration.

The Millennium Ecosystem Assessment (MA) introduced a new framework for analyzing social-ecological systems that has had wide influence in the policy and scientific communities. Studies after the MA are taking up new challenges in the basic science needed to assess, project, and manage flows of ecosystem services and effects on human well-being. Yet, our ability to draw general conclusions remains limited by focus on discipline-bound sectors of the full social-ecological system. At the same time, some polices and practices intended to improve ecosystem services and human well-being are based on untested assumptions and sparse information. The people who are affected and those who provide resources are increasingly asking for evidence that interventions improve ecosystem services and human well-being. New research is needed that considers the full ensemble of processes and feedbacks, for a range of biophysical and social systems, to better understand and manage the dynamics of the relationship between humans and the ecosystems on which they rely. Such research will expand the capacity to address fundamental questions about complex socialecological systems while evaluating assumptions of policies and practices intended to advance human well-being through improved ecosystem services.

Ecosystem service (ES) trade-offs arise from management choices made by humans, which can change the type, magnitude, and relative mix of services provided by ecosystems. Trade-offs occur when the provision of one ES is reduced as a consequence of increased use of another ES. In some cases, a trade-off may be an explicit choice; but in others, trade-offs arise without premeditation or even awareness that they are taking place. Trade-offs in ES can be classified along three axes: spatial scale, temporal scale, and reversibility. Spatial scale refers to whether the effects of the trade-off are felt locally or at a distant location. Temporal scale refers to whether the effects take place relatively rapidly or slowly. Reversibility expresses the likelihood that the perturbed ES may return to its original state if the perturbation ceases. Across all four Millennium Ecosystem Assessment scenarios and selected case study examples, trade-off decisions show a preference for provisioning, regulating, or cultural services (in that order). Supporting services are more likely to be "taken for granted." Cultural ES are almost entirely unquantified in scenario modeling; therefore, the calculated model results do not fully capture losses of these services that occur in the scenarios. The quantitative scenario models primarily capture the services that are perceived by society as more important-provisioning and regulating ecosystem services-and thus do not fully capture tradeoffs of cultural and supporting services. Successful management policies will be those that incorporate lessons learned from prior decisions into future management actions. Managers should complement their actions with monitoring programs that, in addition to monitoring the short-term provisions of services, also monitor the long-term evolution of slowly changing variables. Policies can then be developed to take into account ES trade-offs at multiple spatial and temporal scales. Successful strategies will recognize the inherent complexities of ecosystem management and will work to develop policies that minimize the effects of ES trade-offs.Ecology and Society 11(1): 28 http://www.ecologyandsociety.org/vol11/iss1/art28/ Ecology and Society 11(1): 28 two anonymous reviewers, and the many others who commented on previous versions of the "trade-offs working group" documents. Figures 2 and 4 were kindly prepared by Kathryn M. Rodríguez-Clark.

Humanity is on a deeply unsustainable trajectory. We are exceeding planetary boundaries and unlikely to meet many international sustainable development goals and global environmental targets. Until recently, there was no broadly accepted framework of interventions that could ignite the transformations needed to achieve these desired targets and goals. As a component of the IPBES Global Assessment, we conducted an iterative expert deliberation process with an extensive review of scenarios and pathways to sustainability, including the broader literature on indirect drivers, social change and sustainability transformation. We asked, what are the most important elements of pathways to sustainability? Applying a social–ecological systems lens, we identified eight priority points for intervention (leverage points) and five overarching strategic actions and priority interventions (levers), which appear to be key to societal transformation. The eight leverage points are: (1) Visions of a good life, (2) Total consumption and waste, (3) Latent values of responsibility, (4) Inequalities, (5) Justice and inclusion in conservation, (6) Externalities from trade and other telecouplings, (7) Responsible technology, innovation and investment, and (8) Education and knowledge generation and sharing. The five intertwined levers can be applied across the eight leverage points and more broadly. These include: (A) Incentives and capacity building, (B) Coordination across sectors and jurisdictions, (C) Pre‐emptive action, (D) Adaptive decision‐making and (E) Environmental law and implementation. The levers and leverage points are all non‐substitutable, and each enables others, likely leading to synergistic benefits. Transformative change towards sustainable pathways requires more than a simple scaling‐up of sustainability initiatives—it entails addressing these levers and leverage points to change the fabric of legal, political, economic and other social systems. These levers and leverage points build upon those approved within the Global Assessment's Summary for Policymakers, with the aim of enabling leaders in government, business, civil society and academia to spark transformative changes towards a more just and sustainable world. A free Plain Language Summary can be found within the Supporting Information of this article.

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of soil stability enabled the 2014 catastrophic failure of the Mount Polley tailings dam (5).Furthermore, the issuance of mine permits relies on the promise of mitigations that lack field validation. Canadian industrial projects typically underdeliver on their mitigations, such as restoring fish habitat (6). Unverified technologies can fail, as evidenced by the 2014 fish kill downstream of Teck Resources' wastewater treatment plant (7).Finally, mine assessment and permitting do not require incorporation of transparent, independent, and peer-reviewed science (8). For example, Teck's Elk Valley permit allows contaminant discharges up to 65 times above scientifically established protective thresholds for fish (9). Political borders do not block the downstream flow of this contaminated water into Montana and Idaho (10).Stakes are high. Upstream Canadian mines threaten downstream economies, waters, and ways of life, even as the United States is currently weakening its own federal environmental regulations (11). Rather than a race to the bottom, we urge our governments to honor their mutual obligations to protect our shared transboundary waters as codified in the Boundary Waters Treaty of 1909 (12) and immediately collaborate on binational environmental reviews that are founded upon independent, transparent, and peer-reviewed science.

What does the future hold for the world’s ecosystems and benefits that people obtain from them? While the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) has identified the development of scenarios as a key to helping decision makers identify potential impacts of different policy options, it currently lacks a long-term scenario strategy. IPBES will decide how it will approach scenarios at its plenary meeting on 22–28 February 2016, in Kuala Lumpur. IPBES now needs to decide whether it should create new scenarios that better explore ecosystem services and biodiversity dynamics. For IPBES to capture the social-ecological dynamics of biodiversity and ecosystem services, it is essential to engage with the great diversity of local contexts, while also including the global tele-coupling among local places. We present and compare three alternative scenario strategies that IPBES could use and then suggest a bottom-up, cross-scale scenario strategy to improve the policy relevance of future IPBES assessments. We propose five concrete steps as part of an effective, long term scenario development process for IPBES in cooperation with the scientific community.

Macrobenthic species abundances and blomasses were determined at 31 statlons from Pointe-a-Plerre to La Brea, Trinldad. Thls area is subject to chronic natural 011 seepage and spillage from oil production activities. Multivariate analysis was used to define those environmental variables which best explained community composition. The deeper sltes were impoverished due to the development of anoxia below a pycnocline which formed during the wet season. Abundance/biomass comparison (ABC) plots indicated that macrobenthic communltles near an oil refinery were grossly to moderately stressed while those close to the Trinidad Pltch Lake, one of the largest natural oil seeps In the world, were not. Taxonomic aggregation of the species data to family level resulted In little loss of information in the multlvarlate analyses and apparently Improved the ability of ABC curves to discriminate pollution. Comparisons of the severity of community degradation at these sites using a phylum-level meta-analysis of 'production' were compatible with NE Atlantlc data, which augurs well for the more global applicability of this approach. A feature of the Tnnidad samples is that they all separate along the upper edge of the meta-analys~s 'wedge', due malnly to their higher average proportion of Crustacea relative to Echlnodermata and Mollusca. This IS explained In terms of the estuarine character of the reglon, and suggests that the unexplained vertlcal axis in Warwick & Clarke's (companion article) ordination may be related to natural environmental characteristics INTRODUCTIONOne of the challenges of the benthic community approach to pollution monitoring is to develop a suite of objective analytical protocols which are easy to apply and accessible to laboratories with less sophisticated resources. Comparison of several appropriate methods which may fit these criteria (Gray et al. 1988) shows that they give essentially the same results for a strong pollution gradient (Warwick 1 9 8 8~) .Further, there is little if any loss of information if the data are analysed at higher taxonomic levels (Warwick 1988a, b, Ferraro & Cole 1990, and phylum-level analysis may permit comparative studies of the severity of pollution effects from physically dlssirnilar and geographically distant areas (Warwick & Clarke 1993). These findings may be helpful in many areas of the tropics where the taxonomy of the benthic fauna is not well-known or well-documented. However, the question remains as to whether such techniques are drectly applicable to these areas. In particular, the phylum-level meta-analysis approach has only been applied to NE Atlantic sites. Since it depends on a predictable phyletic composition in unperturbed situations and also on predictable changes in this composition with increasing levels of perturbation, its validity for use on a more global scale needs testing. Here we have done t h s in a tropical setting where natural and man-induced perturbations are many and varied. Firstly, we have assessed the level of community degradati...