A polycentric food sovereignty approach to climate resilience in the Philippines

Enhancing climate resilience in agrarian communities requires improving the underlying socioecological conditions for farmers to engage in adaptation and mitigation strategies, alongside collaborative and redistributive community development to reduce vulnerabilities. To overcome barriers to climate resilience in the Philippines, a grassroots farmer-led organization comprised of resource-poor smallholders, scientists, and nongovernmental organizations have organized a polycentric network over the past 30 years to implement food sovereignty initiatives. We explore the extent to which the network’s decentralized and farmer-led organizational structure; programming and services; promotion of diversified, organic, and agroecological farming systems; and political organizing and advocacy create broadly accessible and diverse pathways for resource-poor smallholders to build climate resilience. We find that the Magsasaka at Siyentipiko para sa Pag-Unlad ng Agrikultura’s (Farmer-Scientist Partnership for Development) polycentric governance approach directly addresses the root causes of vulnerability, particularly in working to reclaim farmer rights and control over resources, connecting local and global struggles, and revitalizing agrobiodiversity and place-based knowledge.

Net heterotrophy in High Arctic first-year and multi-year spring sea ice

The net productivity of sea ice is determined by the physical and geochemical characteristics of the ice–ocean system and the activity of organisms inhabiting the ice. Differences in habitat suitability between first-year and multi-year sea ice can affect the ice algal community composition and acclimation state, introducing considerable variability to primary production within each ice type. In this study, we characterized the biogeochemical variability between adjacent first-year and multi-year sea ice floes in the Lincoln Sea of the Canadian High Arctic, during the May 2018 Multidisciplinary Arctic Program—Last Ice sampling campaign. Combining measurements of transmitted irradiance from a remotely operated underwater vehicle with laboratory-based oxygen optode incubations, this work shows widespread heterotrophy (net oxygen uptake) in the bottom 10 cm of both ice types, particularly in thick multi-year ice (>2.4 m) and early morning of the 24-h day. Algal acclimation state and species composition varied between ice types despite similar net community production due to widespread light and nutrient limitation. The first-year ice algal community was increasingly dominated over spring by the potentially toxin-producing genus Pseudonitzschia that was acclimated to high and variable light conditions characteristic of a thinner ice habitat with mobile snow cover. In comparison, the multi-year ice harbored more shade-acclimated algae of mixed composition. This work highlights the potential for heterotrophy in sea ice habitats of the High Arctic, including first measurements of such O2-uptake in multi-year ice floes. Observed differences in photophysiology between algae of these sea ice types suggests that a shift toward higher light availability and a younger sea ice cover with climate change does not necessarily result in a more productive system. Instead, it may favor future sea ice algal communities of different species composition, with lower photosynthetic potential but greater resilience to stronger and more variable light conditions.

Key challenges for tropospheric chemistry in the Southern Hemisphere

This commentary paper from the recently formed International Global Atmospheric Chemistry (IGAC) Southern Hemisphere Working Group outlines key issues in atmospheric composition research that particularly impact the Southern Hemisphere. In this article, we present a broad overview of many of the challenges for understanding atmospheric chemistry in the Southern Hemisphere, before focusing in on the most significant factors that differentiate it from the Northern Hemisphere. We present sections on the importance of biogenic emissions and fires in the Southern Hemisphere, showing that these emissions often dominate over anthropogenic emissions in many regions. We then describe how these and other factors influence air quality in different parts of the Southern Hemisphere. Finally, we describe the key role of the Southern Ocean in influencing atmospheric chemistry and conclude with a description of the aims and scope of the newly formed IGAC Southern Hemisphere Working Group.

Quantifying the impact of future extreme heat on the outdoor work sector in the United States

Outdoor workers perform critical societal functions, often despite higher-than-average on-the-job risks and below-average pay. Climate change is expected to increase the frequency of days when it is too hot to safely work outdoors, compounding risks to workers and placing new stressors on the personal, local, state, and federal economies that depend on them. After quantifying the number of outdoor workers in the contiguous United States and their median earnings, we couple heat-based work reduction recommendations from the U.S. Centers for Disease Control and Prevention with an analysis of hourly weather station data to develop novel algorithms for calculating the annual number of unsafe workdays due to extreme heat. We apply these algorithms to projections of the frequency of extreme heat days to quantify the exposure of the outdoor workforce to extreme heat and the associated earnings at risk under different emissions scenarios and, for the first time, different adaptation measures. With a trajectory of modest greenhouse gas emissions reductions, outdoor worker exposure to extreme heat would triple that of the late 20th-century baseline by mid-century, and earnings at risk would reach an estimated $39.3 billion annually. By the late century with that same trajectory, exposure would increase four-fold compared to the baseline with an estimated $49.2 billion in annual earnings at risk. Losses are considerably higher with a limited-mitigation trajectory. While universal adoption of 2 specific adaptation measures in conjunction could reduce mid-century and late-century economic risks by roughly 90% and 93%, respectively, practical limitations to their adoption suggest that emissions mitigation policies will be critical for ensuring the well-being and livelihoods of outdoor workers in a warming climate.

An operational overview of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) Northeast Pacific field deployment

The goal of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) field campaign is to develop a predictive understanding of the export, fate, and carbon cycle impacts of global ocean net primary production. To accomplish this goal, observations of export flux pathways, plankton community composition, food web processes, and optical, physical, and biogeochemical (BGC) properties are needed over a range of ecosystem states. Here we introduce the first EXPORTS field deployment to Ocean Station Papa in the Northeast Pacific Ocean during summer of 2018, providing context for other papers in this special collection. The experiment was conducted with two ships: a Process Ship, focused on ecological rates, BGC fluxes, temporal changes in food web, and BGC and optical properties, that followed an instrumented Lagrangian float; and a Survey Ship that sampled BGC and optical properties in spatial patterns around the Process Ship. An array of autonomous underwater assets provided measurements over a range of spatial and temporal scales, and partnering programs and remote sensing observations provided additional observational context. The oceanographic setting was typical of late-summer conditions at Ocean Station Papa: a shallow mixed layer, strong vertical and weak horizontal gradients in hydrographic properties, sluggish sub-inertial currents, elevated macronutrient concentrations and low phytoplankton abundances. Although nutrient concentrations were consistent with previous observations, mixed layer chlorophyll was lower than typically observed, resulting in a deeper euphotic zone. Analyses of surface layer temperature and salinity found three distinct surface water types, allowing for diagnosis of whether observed changes were spatial or temporal. The 2018 EXPORTS field deployment is among the most comprehensive biological pump studies ever conducted. A second deployment to the North Atlantic Ocean occurred in spring 2021, which will be followed by focused work on data synthesis and modeling using the entire EXPORTS data set.

Rise of the rare biosphere

Ocean ecosystems are changing, and the climate envelope paradigm predicts a steady shift, approximately poleward, of species ranges. The Gulf of Maine presents a test case of this paradigm, as temperatures have warmed extremely rapidly. Some species have shifted northeastward, matching predictions. Others—namely harmful algal species like Pseudo-nitzschia australis and Karenia mikimotoi—do not appear to have followed climate trajectories, arriving as surprises in the Gulf of Maine. Rare-biosphere dynamics offer one possible ecological lens for understanding and predicting this type of surprise. Rare species in the plankton, possibly more so than southerly ones, may provide management challenges in the future. Improved monitoring and broader coordination of monitoring of the rare biosphere could help develop early warning systems for harmful and toxic algae. A better theoretical understanding of rare biosphere dynamics is also needed. A challenge for the next cohort of ecosystem projections is to predict the newly emerging harmful species of the type that catch us by surprise.

Simulated impacts of relative climate change and river discharge regulation on sea ice and oceanographic conditions in the Hudson Bay Complex

In this analysis, we examine relative contributions from climate change and river discharge regulation to changes in marine conditions in the Hudson Bay Complex using a subset of five atmospheric forcing scenarios from the Coupled Model Intercomparison Project Phase 5 (CMIP5), river discharge data from the Hydrological Predictions for the Environment (HYPE) model, both naturalized (without anthropogenic intervention) and regulated (anthropogenically controlled through diversions, dams, reservoirs), and output from the Nucleus for European Modeling of the Ocean Ice-Ocean model for the 1981–2070 time frame. Investigated in particular are spatiotemporal changes in sea surface temperature, sea ice concentration and thickness, and zonal and meridional sea ice drift in response to (i) climate change through comparison of historical (1981–2010) and future (2021–2050 and 2041–2070) simulations, (ii) regulation through comparison of historical (1981–2010) naturalized and regulated simulations, and (iii) climate change and regulation combined through comparison of future (2021–2050 and 2041–2070) naturalized and regulated simulations. Also investigated is use of the diagnostic known as e-folding time spatial distribution to monitor changes in persistence in these variables in response to changing climate and regulation impacts in the Hudson Bay Complex. Results from this analysis highlight bay-wide and regional reductions in sea ice concentration and thickness in southwest and northeast Hudson Bay in response to a changing climate, and east-west asymmetry in sea ice drift response in support of past studies. Regulation is also shown to amplify or suppress the climate change signal. Specifically, regulation amplifies sea surface temperatures from April to August, suppresses sea ice loss by approximately 30% in March, contributes to enhanced sea ice drift speed by approximately 30%, and reduces meridional circulation by approximately 20% in January due to enhanced zonal drift. Results further suggest that the offshore impacts of regulation are amplified in a changing climate.

Community health workers as a sustainable health care innovation

Health care delivery in the Circumpolar North is challenged by a scarcity of culturally relevant health care services, few medical providers trained in cross-cultural care, and high costs of transportation. Community health workers (CHWs) are primarily Indigenous individuals who provide on-the-ground health care and health promotion services in their own communities. The CHWs’ scope of work varies from health education to clinical care and often focuses on upstream factors that impact the public’s health. Although often overlooked and underutilized, the CHW role is an innovative approach to promoting more sustainable and culturally relevant care within health systems. Investigating and understanding the potential ways that CHW-integrated health care systems support health and wellness could allow for a clearer understanding of how to translate this approach to other regions seeking a transition to sustainability in health and wellness. Drawing on experiences with CHWs in the Circumpolar North, this article introduces a conceptual model summarizing pathways that describe how integrating CHWs supports wellness in their communities. The proposed model includes five pathways for how CHWs could support wellness: (1) the recruitment of CHWs from within a community promotes community capacity and control; (2) the CHW role allows them to advocate to address structural and systemic inequalities that contribute to ill health, if CHWs are supported to organize their communities around wellness; (3) CHWs have the potential to support and empower community members; (4) CHWs have the potential to develop culturally relevant, feasible, and effective health promotion strategies; and (5) CHWs have the potential to build on community strengths. This model allows for CHW-integrated health care systems to be critically examined to both test and refine this proposed model, and support and empower community health workers as a transition to a more sustainable health care delivery system that reduces inequities and promotes health.

Contamination characteristics, mass concentration, and source analysis of metal elements in PM2.5 in Lanzhou, China

PM2.5 and its bound metals pose a serious threat to human health. Understanding their contamination characteristics and source could provide implication for controlling their spreading and ensuring air quality. In this article, 1,600 of PM2.5 samples were collected from 5 urban sites in Lanzhou, China. The contamination characteristics of PM2.5, its relationship with meteorological factors, and the source of its bound metals were studied based on multiple linear regression analysis, enrichment factor (EF), principal component analysis and correlation analysis. The outcomes show that the PM2.5 concentrations in winter (0.117 mg·m–3) and spring (0.083 mg·m–3) are higher than those in summer (0.043 mg·m–3) and autumn (0.048 mg·m–3). The influence degree of meteorological factors on PM2.5 concentration is in the order of wind speed > atmospheric pressure > temperature > humidity. The major source of Fe and Cu in PM2.5 is construction dust, Pb and As is industrial, and Hg is coal combustion. In addition, Cd, V, Co, and Mn are mainly derived from dust produced by weathering of soil or rock. In general, the spatiotemporal distribution of PM2.5 and its bound metals are different, which is closely related to geographical location, source, and meteorological factors. The results in this article could provide support for the scientific formulation to prevent air pollution in Lanzhou.