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The latitudinal diversity gradient (LDG), where the number of species increases from the poles to the Equator, ranks among the broadest and most notable biodiversity patterns on Earth. The pattern of species-rich tropics relative to species-poor temperate areas has been recognized for well over a century, but the generative mechanisms are still debated vigorously. We use simulations to test whether spatio-temporal climatic changes could generate large-scale patterns of biodiversity as a function of only three biological processes-speciation, extinction and dispersal-omitting adaptive niche evolution, diversity-dependence and coexistence limits. In our simulations, speciation resulted from range disjunctions, whereas extinction occurred when no suitable sites were accessible to species. Simulations generated clear LDGs that closely match empirical LDGs for three major vertebrate groups. Higher tropical diversity primarily resulted from higher low-latitude speciation, driven by spatio-temporal variation in precipitation rather than in temperature. This suggests that spatio-temporal changes in low-latitude precipitation prompted geographical range disjunctions over Earth's history, leading to high rates of allopatric speciation that contributed to LDGs. Overall, we show that major global biodiversity patterns can derive from interactions of species' niches (fixed a priori in our simulations) with dynamic climate across complex, existing landscapes, without invoking biotic interactions or niche-related adaptations.

Climate change is an immediate and future threat to food security globally. The consequences for fisheries and agriculture production potential are well studied, yet the possible outcomes for aquaculture (that is, aquatic farming)-one of the fastest growing food sectors on the planet-remain a major gap in scientific understanding. With over one-third of aquaculture produced in marine waters and this proportion increasing, it is critical to anticipate new opportunities and challenges in marine production under climate change. Here, we model and map the effect of warming ocean conditions (Representative Concentration Pathway scenario 8.5) on marine aquaculture production potential over the next century, based on thermal tolerance and growth data of 180 cultured finfish and bivalve species. We find heterogeneous patterns of gains and losses, but an overall greater probability of declines worldwide. Accounting for multiple drivers of species growth, including shifts in temperature, chlorophyll and ocean acidification, reveals potentially greater declines in bivalve aquaculture compared with finfish production. This study addresses a missing component in food security research and sustainable development planning by identifying regions that will face potentially greater climate change challenges and resilience with regards to marine aquaculture in the coming decades. Understanding the scale and magnitude of future increases and reductions in aquaculture potential is critical for designing effective and efficient use and protection of the oceans, and ultimately for feeding the planet sustainably.

Climate warming has caused the seasonal timing of many components of ecological food chains to advance. In the context of trophic interactions, the match-mismatch hypothesis postulates that differential shifts can lead to phenological asynchrony with negative impacts for consumers. However, at present there has been no consistent analysis of the links between temperature change, phenological asynchrony and individual-to-population-level impacts across taxa, trophic levels and biomes at a global scale. Here, we propose five criteria that all need to be met to demonstrate that temperature-mediated trophic asynchrony poses a growing risk to consumers. We conduct a literature review of 109 papers studying 129 taxa, and find that all five criteria are assessed for only two taxa, with the majority of taxa only having one or two criteria assessed. Crucially, nearly every study was conducted in Europe or North America, and most studies were on terrestrial secondary consumers. We thus lack a robust evidence base from which to draw general conclusions about the risk that climate-mediated trophic asynchrony may pose to populations worldwide.

Objective: The Lighthouse Project (2017-2018) explored the role that faith-based organizations (FBOs) might play as resilience hubs for climate-related stresses and extreme weather emergencies in disadvantaged urban environments of three cities. This paper discusses the role that public health played in these initiatives and makes an appeal for more participatory, community-engaged public health in light of the persistent gaps in its approach to equitable climate change preparedness., Methods: Pilots were initiated in the Greater Toronto and Hamilton Area (GTHA): Brampton's Emergency Managers offered pre-selected FBO volunteers specialized training to be part of the city's emergency response in establishing FBO sites as emergency muster stations. An environmental organization in Hamilton explored how its existing networks could rally around a local social resilience challenge, and a community organizer in Toronto undertook network building to support mostly newcomer populations in one inner-city neighbourhood. All pilots used a mix of cold calling, workshops, municipal presentations, and participation in local programming and public events. Two convened local working groups., Results: By the end of the pilot, Brampton's Emergency Management Office had made one contractual relationship with an FBO and its volunteers. In Hamilton, a multi-stakeholder network emerged to support the climate preparedness of agencies serving local vulnerable populations. In Toronto, a residents' working group was established to address neighbour well-being and emergency response in one apartment tower. Work in all three communities is ongoing., Conclusion: Multi-stakeholder support for community organizations and local volunteers can enable partnerships in neighbourhood-level climate resilience-before, during and after extreme weather events. Public Health, while not typically top-of-mind as a key ally in this work, is well positioned to make a contribution. Consistent with place-based approaches, an emergent community development design enabled community animators to catalyze collaborations to suit the on-the-ground realities of each site.

Setting: Climate change is one of the greatest threats to global health in the twenty-first century and has recently been declared a health emergency. The lack of effective dissemination of emerging evidence on climate change health risks, effects, and innovative interventions to health professionals presents one of the greatest challenges to climate action today., Intervention: To identify and address the knowledge gaps at the intersection of health and climate change, the Canadian Coalition for Global Health Research (CCGHR) established a Working Group on Climate Change and Health (WGCCH). WGCCH is evolving organically into a community of practice (CoP) that aims to elevate knowledge brokering on climate change and health and expand to global multi-, inter-, and transdisciplinary realms., Outcomes: To date, the WGCCH established a regular webinar series to share expert knowledge from around the world on intersections between climate change and health, developed short summaries on climate change impacts on broad health challenges, supported young professional training, and enhanced climate health research capacity and skills through collegial network development and other collaborative projects that emerged from CoP activities., Implications: This paper proposes that WGCCH may serve as an example of an effective strategy to address the lack of opportunities for collaborative engagement and mutual learning between health researchers and practitioners, other disciplines, and the general public. Our experiences and lessons learned provide opportunities to learn from the growing pains and successes of an emerging climate change and health-focused CoP.

Setting: Public health practitioners are called to effectively communicate with the public on climate change. The climate crisis requires swift action that starts with public awareness of climate-related health impacts and leads to public support for individual, community and systemic actions to mitigate and adapt to climate change., Intervention: This paper discusses learnings about public opinion research and communication strategies and how a health-focused climate communication campaign-#MakeItBetter-could help to increase awareness and engage new audiences, including public health partners, in conversations about climate change in order to reduce climate-related health impacts for current and future generations. The #MakeItBetter campaign was grounded in evidence-informed messaging, being sensitive to health inequities. Emerging research and pre-campaign testing suggest that framing climate change as a health issue is a promising practice., Outcomes: The #MakeItBetter campaign appeals to parents/caregivers to learn more about climate-related health impacts, take protective action for children and support multi-level climate action. The campaign launch secured 89 news stories, including multicultural media coverage. Longer-term evaluation is required to determine the campaign's effectiveness in building public support for climate action., Implications: An innovative approach to climate communication that draws on the intersections between behavioural and climate sciences and engages in multi-sectoral collaboration can spur both climate action and health protection, aiding public health practitioners and partners in effectively communicating the urgency for climate action. More work is needed to support communication on climate change as an inequity multiplier and promote climate action and community resilience for health equity co-benefits.

Climate change is increasingly impacting population health outcomes related to several areas of public health service delivery across Canada, and internationally. As a result, public health practitioners are increasingly looking for guidance on how to begin planning for and adapting to a myriad of health-related climate impacts. This paper outlines several benefits for local or regional health agencies in conducting climate change and health vulnerability assessments (CCHVAs), based on the author's experience in conducting two of Canada's first comprehensive assessments. These benefits include, but are not limited to establishing suitable baseline understandings of past, present, and future climate-related health risks; providing guidance on mechanisms to reduce health inequities that may be exacerbated by climate change; generating credibility for health agencies to engage with climate change and pursue collaborative, intersectoral relationships with a range of likely and unlikely allies; identifying suitable, cost-effective adaptation options in the form of public health programming; and encouraging decision-makers to produce proactive policy actions to redress potential climate impacts on population health. Completing a CCHVA can directly optimize health agencies' and their allies' efforts to respond to the health imperatives associated with climate change, while also fueling adaptation options that yield co-benefits across a variety of sectors.