Government of Canada

The climate intervention approach marine cloud brightening (MCB) would aim to reduce climate warming by injecting sea salt aerosol (iSSA) into the lower troposphere to increase cloud albedo, reflect more sunlight, and cool the surface. Due to the short atmospheric lifetime of tropospheric aerosol, MCB iSSA emissions and their resulting radiative forcing are regional by nature. This presents a significant challenge and opportunity, as there are many potential MCB implementation patterns that could produce widely varying climate responses. Previous modeling studies suggest that MCB implementation in the subtropical oceans can cause global cooling but often result in remote regional temperature and precipitation responses that may be considered undesirable. Here, we use three Earth system models (ESMs) to estimate the impact of MCB implementation in 14 different ocean regions, assessing MCB forcing and cooling efficiency in each region and examining the patterns of temperature response from each case. We find that iSSA emissions in the midlatitude oceans produce stronger cloud forcing, greater cooling efficiency, and more spatially uniform cooling. With this information, we evaluate a novel MCB emission strategy that emits iSSA in the midlatitude oceans. The ESMs show this iSSA emission pattern produces temperature and precipitation responses across all three ESMs that are quite similar in pattern (but of opposite sign) to the greenhouse gas (GHG) response. Thus, compared to previously tested iSSA injection patterns, midlatitude MCB implementations may be more suitable when intending to maintain climates close to present-day conditions.

Historically, research and monitoring of bird populations has been conducted with in-person point counts; however, passive acoustic monitoring (PAM) recordings transcribed by experts (“PAM point counts”) are rapidly replacing in-person surveys as an approach for counting birds. We reviewed the literature and used case-matched datasets from North America’s boreal forest to show that despite similarities in data structure, in-person and PAM point counts have fundamental differences in the detection process that lead to differences in detectability estimates from distance and removal sampling models. Observer effects on cue rate were more pronounced in PAM than in-person point counts. Cue rate estimates from PAM were significantly higher than from point counts due to earlier time of first detection in PAM point counts, the availability of data with higher-resolution time intervals in removal models, and the exclusion of visual detections. In contrast, exclusion of visual detections from point-count data estimates resulted in lower estimates of perceptibility. Cumulative lower values of detectability estimates from in-person point counts resulted in 15% higher density estimates on average when applied as statistical offsets. We suggest some of the differences in detectability estimates between survey methods are due to human error and/or failure of statistical assumptions and that availability estimates for species that are at least 90% aurally-detected should be preferentially derived from PAM data to reduce bias in density estimates for conservation applications and facilitate continued integration of historic and contemporary point-count datasets. Future research should focus on alternatives to removal modelling and understanding the detection process of automated classifiers to continue to improve detectability estimates and maximize the ability to integrate datasets across data types.

Introduction Giraffe populations across Africa face increasing pressures from habitat loss, poaching, and climate-driven resource scarcity, often intensifying interactions with nearby communities. In eastern Kenya, these pressures have contributed to emerging human-giraffe conflict (HGC), including crop losses, competition for water, and occasional livestock injuries. Although this reticulated giraffes play an important ecosystem role in the African savanna and the socio-economic well-being of African communities, their interactions with people, and how communities perceive and navigate HGC especially in non-tourism regions remains understudied.Methods To address this gap, we conducted 400 structured interviews with households around Bour-Algy Giraffe Sanctuary to assess local interactions with giraffes, attitudes, perceived risks, conflict drivers and preferred strategies for coexistence.Results On average, respondents generally possessed positive attitudes towards giraffes and, on average, respondents did not see giraffes as a risk: to personal or children's safety, of disease transfer, to cattle productivity, or the integrity of the land. Risk perception even decreased if a respondent had encountered a giraffe. Interestingly, giraffes were perceived not to cause damage to land or other property by 59% of participants thus highlighting that it may be possible to promote co-existence in the region for a majority of people. Competition for water, lack of awareness on giraffe ecology, giraffe habitat encroachment, and poverty were raised as the four main cause of conflict. Respondents supported the use of fire, torches, and dogs as way to deter giraffes from farms.Discussion Our findings reveal a landscape where conflict exists but remains manageable, and where strong community support for giraffe presence provides a foundation for conflict transformation. Because of the proximity of giraffes to farms and homesteads, economic activities such as agriculture and cultural tourism, women-led acacia tree nurseries, invasive prosopis control and utilization along with opening up water corridors may motivate communities and minimize HGC. Our work provides a basis for action by the community and policy makers to promote giraffe-farmer co-existence in eastern Kenya.

This review systematically synthesizes technological synergies within a Community Energy System (CES), emphasizing cold-climate contexts where heating-dominant demand profiles and strong seasonality create distinct operational challenges. Drawing on 115 studies (2010–2024), the paper explores how integrated thermal, electrical, and digital infrastructures support net-zero and climate-resilient communities in regions with substantial heating requirements. Thermal–electrical coupling emerges as a foundational mechanism in cold climates, where heating loads dominate annual energy demand and drive winter peak constraints. Power-to-Heat (P2H) systems, cold-climate heat pumps, and hybrid configurations combining Thermal Energy Storage (TES) with Battery Energy Storage Systems (BESS) enable multi-timescale flexibility, allowing renewable energy to be shifted from hours to seasons. District Energy Systems (DES) act as a thermal backbone, enabling this integration across extended heating seasons and transforming thermal demand into a grid-balancing resource. Digital technologies further enhance system coordination under variable climatic conditions. Artificial Intelligence (AI), the Internet of Things (IoT), and Advanced Metering Infrastructure (AMI) support real-time optimization, demand response, and cross-vector control within Renewable Energy Communities (RECs) and Virtual Power Plants (VPPs). At the system level, decentralized architectures—including microgrids, Non-Wire Alternatives (NWAs), and peer-to-peer (P2P) trading—strengthen resilience by maintaining thermal and electrical continuity during grid disruptions. Building on these findings, the review synthesizes cross-cutting technological synergies and proposes deployment pathways tailored to cold-climate CES, supported by comparative case studies. Despite demonstrated benefits, widespread adoption remains constrained by high upfront costs, interoperability challenges, and fragmented regulatory frameworks. The review concludes with policy, governance, and research recommendations to enable scalable, equitable, and climate-responsive CES deployment in heating-dominated regions.

Interactions between groundwater and surface water (GW-SW) strongly influence streamflow dynamics and solute transport, especially in urban catchments where discharging groundwater can be a notable source of contaminants, such as chloride (Cl-). Across the Great Lakes Basin, extensive road salt use has led to chronically high Cl- concentrations in groundwater, raising concerns about its long-term contribution to surface water salinization. Understanding the spatiotemporal dynamics of GW-SW exchange is essential for evaluating Cltransport and its impacts on urban water quality. This study examines GW-SW interactions and Cl- dynamics in an urban stream in southern Ontario, Canada, over a 2-year field campaign (May 2022 - April 2024), aiming to characterize exchange variability, assess groundwater's role in shaping in-stream Cl- concentrations, and evaluate local hydrogeologic controls. A multimethod approach was used, including streambed temperature mapping and vertical profiles, seepage meters, hydraulic gradient measurements, and geochemical sampling (delta 18O, delta 2H, and Cl-) to assess exchange dynamics and relative groundwater contributions. Results revealed spatial variability in groundwater discharge, with persistent upward flow confirmed by temperature-based methods and Darcy's Law. Concentrations of Cl- in groundwater consistently exceeded aquatic life guidelines (120-640 mg/L), particularly in the streambed drive-points, indicating persistent Clloading to surface water, even outside of winter months. These findings highlight the importance of groundwater as a long-term Cl- source in urban streams and demonstrate the value of an integrated approach for evaluating GW-SW interactions in cold-region watersheds.