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Twenty-five years since foundational publications on valuing ecosystem services for human well-being 1 , 2 , addressing the global biodiversity crisis 3 still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever 4 . Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF) 5 and the UN Sustainable Development Goals 6 , predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature 7 . Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change 8 , pandemic emergence 9 and socio-environmental injustices 10 . On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions 7 , 11 . Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures. Following a wide-ranging review of studies, reports and policies about nature’s multiple values, combinations of values-centred approaches are proposed to improve valuation of nature, address barriers to uptake in decision-making, and make transformative changes towards more just and sustainable futures.

Lakes are important natural resources and carbon gas emitters and are undergoing rapid changes worldwide in response to climate change and human activities. A detailed global characterization of lakes and their long-term dynamics does not exist, which is however crucial for evaluating the associated impacts on water availability and carbon emissions. Here, we map 3.4 million lakes on a global scale, including their explicit maximum extents and probability-weighted area changes over the past four decades. From the beginning period (1984–1999) to the end (2010–2019), the lake area increased across all six continents analyzed, with a net change of +46,278 km 2 , and 56% of the expansion was attributed to reservoirs. Interestingly, although small lakes (<1 km 2 ) accounted for just 15% of the global lake area, they dominated the variability in total lake size in half of the global inland lake regions. The identified lake area increase over time led to higher lacustrine carbon emissions, mostly attributed to small lakes. Our findings illustrate the emerging roles of small lakes in regulating not only local inland water variability, but also the global trends of surface water extent and carbon emissions. Lakes are essential components of the hydrological and biogeochemical cycles. Here, Pi et al develop a global lake dataset called GLAKES via high-resolution satellite images and deep learning to examine global lake changes over four decades.

Nitrous oxide (N 2 O), like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N 2 O concentrations have contributed to stratospheric ozone depletion 1 and climate change 2 , with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N 2 O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. Here we present a global N 2 O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N 2 O emissions. We use bottom-up (inventory, statistical extrapolation of flux measurements, process-based land and ocean modelling) and top-down (atmospheric inversion) approaches to provide a comprehensive quantification of global N 2 O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016. Global N 2 O emissions were 17.0 (minimum–maximum estimates: 12.2–23.5) teragrams of nitrogen per year (bottom-up) and 16.9 (15.9–17.7) teragrams of nitrogen per year (top-down) between 2007 and 2016. Global human-induced emissions, which are dominated by nitrogen additions to croplands, increased by 30% over the past four decades to 7.3 (4.2–11.4) teragrams of nitrogen per year. This increase was mainly responsible for the growth in the atmospheric burden. Our findings point to growing N 2 O emissions in emerging economies—particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N 2 O–climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N 2 O emissions exceeds some of the highest projected emission scenarios 3 , 4 , underscoring the urgency to mitigate N 2 O emissions. Bottom-up and top-down approaches are used to quantify global nitrous oxide sources and sinks resulting from both natural and anthropogenic sources, revealing a 30% increase in global human-induced emissions between 1980 and 2016.

As climate change research becomes increasingly applied, the need for actionable information is growing rapidly. A key aspect of this requirement is the representation of uncertainties. The conventional approach to representing uncertainty in physical aspects of climate change is probabilistic, based on ensembles of climate model simulations. In the face of deep uncertainties, the known limitations of this approach are becoming increasingly apparent. An alternative is thus emerging which may be called a ‘storyline’ approach. We define a storyline as a physically self-consistent unfolding of past events, or of plausible future events or pathways. No a priori probability of the storyline is assessed; emphasis is placed instead on understanding the driving factors involved, and the plausibility of those factors. We introduce a typology of four reasons for using storylines to represent uncertainty in physical aspects of climate change: (i) improving risk awareness by framing risk in an event-oriented rather than a probabilistic manner, which corresponds more directly to how people perceive and respond to risk; (ii) strengthening decision-making by allowing one to work backward from a particular vulnerability or decision point, combining climate change information with other relevant factors to address compound risk and develop appropriate stress tests; (iii) providing a physical basis for partitioning uncertainty, thereby allowing the use of more credible regional models in a conditioned manner and (iv) exploring the boundaries of plausibility, thereby guarding against false precision and surprise. Storylines also offer a powerful way of linking physical with human aspects of climate change.

The scale, rate, and intensity of humans' environmental impact has engendered broad discussion about how to find plausible pathways of development that hold the most promise for fostering a better future in the Anthropocene. However, the dominance of dystopian visions of irreversible environmental degradation and societal collapse, along with overly optimistic Utopias and business-as-usual scenarios that lack insight and innovation, frustrate progress. Here, we present a novel approach to thinking about the future that builds on experiences drawn from a diversity of practices, worldviews, values, and regions that could accelerate the adoption of pathways to transformative change (change that goes beyond incremental improvements). Using an analysis of 100 initiatives, or \"seeds of a good Anthropocene\", we find that emphasizing hopeful elements of existing practice offers the opportunity to: (1) understand the values and features that constitute a good Anthropocene, (2) determine the processes that lead to the emergence and growth of initiatives that fundamentally change human-environmental relationships, and (3) generate creative, bottom-up scenarios that feature well-articulated pathways toward a more positive future.

Both a high number of species and abundance in multiple trophic levels are required for ecosystems to continue to provide the services humans require of them. The importance of biodiversity in depth Numerous experiments have shown that the loss of biodiversity within single trophic groups — groups of organisms consuming resources from a similar level in the food chain — reduces the ability of ecosystems to deliver the services on which humans depend. How the loss of biodiversity in natural ecosystems consisting of multiple interacting trophic groups affects ecosystem functioning has remained unclear. Santiago Soliveres et al . have compiled data on the richness and abundance of 4,600 microbial, plant and animal taxa in 150 grasslands in Germany, together with information on 14 ecosystem services. Their analysis of the data demonstrates that biodiversity across multiple trophic groups is as important for the functioning of ecosystems as land-use intensity or environmental conditions. They conclude that the preservation of high levels of richness and diversity within a wide range of taxa will be key to ensuring that ecosystems continue to deliver the services on which humans rely. The findings also inform conservation and ecosystem management strategies by highlighting the most functionally relevant organisms, which include plants, soil bacteria and herbivorous insects. Many experiments have shown that loss of biodiversity reduces the capacity of ecosystems to provide the multiple services on which humans depend 1 , 2 . However, experiments necessarily simplify the complexity of natural ecosystems and will normally control for other important drivers of ecosystem functioning, such as the environment or land use. In addition, existing studies typically focus on the diversity of single trophic groups, neglecting the fact that biodiversity loss occurs across many taxa 3 , 4 and that the functional effects of any trophic group may depend on the abundance and diversity of others 5 , 6 . Here we report analysis of the relationships between the species richness and abundance of nine trophic groups, including 4,600 above- and below-ground taxa, and 14 ecosystem services and functions and with their simultaneous provision (or multifunctionality) in 150 grasslands. We show that high species richness in multiple trophic groups (multitrophic richness) had stronger positive effects on ecosystem services than richness in any individual trophic group; this includes plant species richness, the most widely used measure of biodiversity. On average, three trophic groups influenced each ecosystem service, with each trophic group influencing at least one service. Multitrophic richness was particularly beneficial for ‘regulating’ and ‘cultural’ services, and for multifunctionality, whereas a change in the total abundance of species or biomass in multiple trophic groups (the multitrophic abundance) positively affected supporting services. Multitrophic richness and abundance drove ecosystem functioning as strongly as abiotic conditions and land-use intensity, extending previous experimental results 7 , 8 to real-world ecosystems. Primary producers, herbivorous insects and microbial decomposers seem to be particularly important drivers of ecosystem functioning, as shown by the strong and frequent positive associations of their richness or abundance with multiple ecosystem services. Our results show that multitrophic richness and abundance support ecosystem functioning, and demonstrate that a focus on single groups has led to researchers to greatly underestimate the functional importance of biodiversity.

The tremendous increases in production of plastic materials has led to an accumulation of plastic pollution worldwide. Many studies have addressed the physical effects of large-sized plastics on organisms, whereas few have focused on plastic nanoparticles, despite their distinct chemical, physical and mechanical properties. Hence our understanding of their effects on ecosystem function, behaviour and metabolism of organisms remains elusive. Here we demonstrate that plastic nanoparticles reduce survival of aquatic zooplankton and penetrate the blood-to-brain barrier in fish and cause behavioural disorders. Hence, for the first time, we uncover direct interactions between plastic nanoparticles and brain tissue, which is the likely mechanism behind the observed behavioural disorders in the top consumer. In a broader perspective, our findings demonstrate that plastic nanoparticles are transferred up through a food chain, enter the brain of the top consumer and affect its behaviour, thereby severely disrupting the function of natural ecosystems.

While it is understood that cities generate the majority of carbon emissions, for most cities, towns, and rural areas around the world no carbon footprint (CF) has been estimated. The Gridded Global Model of City Footprints (GGMCF) presented here downscales national CFs into a 250 m gridded model using data on population, purchasing power, and existing subnational CF studies from the US, China, EU, and Japan. Studies have shown that CFs are highly concentrated by income, with the top decile of earners driving 30%-45% of emissions. Even allowing for significant modeling uncertainties, we find that emissions are similarly concentrated in a small number of cities. The highest emitting 100 urban areas (defined as contiguous population clusters) account for 18% of the global carbon footprint. While many of the cities with the highest footprints are in countries with high carbon footprints, nearly one quarter of the top cities (41 of the top 200) are in countries with relatively low emissions. In these cities population and affluence combine to drive footprints at a scale similar to those of cities in high-income countries. We conclude that concerted action by a limited number of local governments can have a disproportionate impact on global emissions.

The chemical complexity of atmospheric organic aerosol (OA) has caused substantial uncertainties in understanding its origins and environmental impacts. Here, we provide constraints on OA origins through compositional characterization with molecular-level details. Our results suggest that secondary OA (SOA) from monoterpene oxidation accounts for approximately half of summertime fine OA in Centreville, AL, a forested area in the southeastern United States influenced by anthropogenic pollution. We find that different chemical processes involving nitrogen oxides, during days and nights, play a central role in determining the mass of monoterpene SOA produced. These findings elucidate the strong anthropogenic–biogenic interaction affecting ambient aerosol in the southeastern United States and point out the importance of reducing anthropogenic emissions, especially under a changing climate, where biogenic emissions will likely keep increasing.