scholarly journals Climate change and ocean deoxygenation within intensified surface-driven upwelling circulations

Author(s):  
Andrew Bakun

Ocean deoxygenation often takes place in proximity to zones of intense upwelling. Associated concerns about amplified ocean deoxygenation arise from an arguable likelihood that coastal upwelling systems in the world's oceans may further intensify as anthropogenic climate change proceeds. Comparative examples discussed include the uniquely intense seasonal Somali Current upwelling, the massive upwelling that occurs quasi-continuously off Namibia and the recently appearing and now annually recurring ‘dead zone’ off the US State of Oregon. The evident ‘transience’ in causal dynamics off Oregon is somewhat mirrored in an interannual-scale intermittence in eruptions of anaerobically formed noxious gases off Namibia. A mechanistic scheme draws the three examples towards a common context in which, in addition to the obvious but politically problematic remedy of actually reducing ‘greenhouse’ gas emissions, the potentially manageable abundance of strongly swimming, finely gill raker-meshed small pelagic fish emerges as a plausible regulating factor. This article is part of the themed issue ‘Ocean ventilation and deoxygenation in a warming world’.

Author(s):  
John G. Shepherd ◽  
Peter G. Brewer ◽  
Andreas Oschlies ◽  
Andrew J. Watson

Changes of ocean ventilation rates and deoxygenation are two of the less obvious but important indirect impacts expected as a result of climate change on the oceans. They are expected to occur because of (i) the effects of increased stratification on ocean circulation and hence its ventilation, due to reduced upwelling, deep-water formation and turbulent mixing, (ii) reduced oxygenation through decreased oxygen solubility at higher surface temperature, and (iii) the effects of warming on biological production, respiration and remineralization. The potential socio-economic consequences of reduced oxygen levels on fisheries and ecosystems may be far-reaching and significant. At a Royal Society Discussion Meeting convened to discuss these matters, 12 oral presentations and 23 posters were presented, covering a wide range of the physical, chemical and biological aspects of the issue. Overall, it appears that there are still considerable discrepancies between the observations and model simulations of the relevant processes. Our current understanding of both the causes and consequences of reduced oxygen in the ocean, and our ability to represent them in models are therefore inadequate, and the reasons for this remain unclear. It is too early to say whether or not the socio-economic consequences are likely to be serious. However, the consequences are ecologically, biogeochemically and climatically potentially very significant, and further research on these indirect impacts of climate change via reduced ventilation and oxygenation of the oceans should be accorded a high priority. This article is part of the themed issue ‘Ocean ventilation and deoxygenation in a warming world’.


Author(s):  
J. R. McNeill

This chapter discusses the emergence of environmental history, which developed in the context of the environmental concerns that began in the 1960s with worries about local industrial pollution, but which has since evolved into a full-scale global crisis of climate change. Environmental history is ‘the history of the relationship between human societies and the rest of nature’. It includes three chief areas of inquiry: the study of material environmental history, political and policy-related environmental history, and a form of environmental history which concerns what humans have thought, believed, written, and more rarely, painted, sculpted, sung, or danced that deals with the relationship between society and nature. Since 1980, environmental history has come to flourish in many corners of the world, and scholars everywhere have found models, approaches, and perspectives rather different from those developed for the US context.


2020 ◽  
Vol 26 (3) ◽  
Author(s):  
Linda J. Bilmes

AbstractThe United States has traditionally defined national security in the context of military threats and addressed them through military spending. This article considers whether the United States will rethink this mindset following the disruption of the Covid19 pandemic, during which a non-military actor has inflicted widespread harm. The author argues that the US will not redefine national security explicitly due to the importance of the military in the US economy and the bipartisan trend toward growing the military budget since 2001. However, the pandemic has opened the floodgates with respect to federal spending. This shift will enable the next administration to allocate greater resources to non-military threats such as climate change and emerging diseases, even as it continues to increase defense spending to address traditionally defined military threats such as hypersonics and cyberterrorism.


2021 ◽  
Vol 56 (3) ◽  
pp. 174-177
Author(s):  
Karl Aiginger

AbstractAfter President Trump’s departure, many expected that the transatlantic partnership would return to its previous state with the US playing a leading role. This article challenges that view. Instead, a new world order is foreseen, with different partnerships and spheres of influence. Europe can decide whether it wants to remain small and homogeneous or a larger but also more heterogenous Union that leads in welfare indicators such as life expectancy, fighting poverty and limiting climate change. Expanding this lead and communicating its uniqueness can empower Europe to combine enlargement and deepening, which appears unlikely without changes in governance and self-confidence.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pamela A. Fernández ◽  
Jorge M. Navarro ◽  
Carolina Camus ◽  
Rodrigo Torres ◽  
Alejandro H. Buschmann

AbstractThe capacity of marine organisms to adapt and/or acclimate to climate change might differ among distinct populations, depending on their local environmental history and phenotypic plasticity. Kelp forests create some of the most productive habitats in the world, but globally, many populations have been negatively impacted by multiple anthropogenic stressors. Here, we compare the physiological and molecular responses to ocean acidification (OA) and warming (OW) of two populations of the giant kelp Macrocystis pyrifera from distinct upwelling conditions (weak vs strong). Using laboratory mesocosm experiments, we found that juvenile Macrocystis sporophyte responses to OW and OA did not differ among populations: elevated temperature reduced growth while OA had no effect on growth and photosynthesis. However, we observed higher growth rates and NO3− assimilation, and enhanced expression of metabolic-genes involved in the NO3− and CO2 assimilation in individuals from the strong upwelling site. Our results suggest that despite no inter-population differences in response to OA and OW, intrinsic differences among populations might be related to their natural variability in CO2, NO3− and seawater temperatures driven by coastal upwelling. Further work including additional populations and fluctuating climate change conditions rather than static values are needed to precisely determine how natural variability in environmental conditions might influence a species’ response to climate change.


2019 ◽  
Vol 28 (7) ◽  
pp. 797-811 ◽  
Author(s):  
Brianne Suldovsky ◽  
Asheley Landrum ◽  
Natalie Jomini Stroud

In an era where expertise is increasingly critiqued, this study draws from the research on expertise and scientist stereotyping to explore who the public considers to be a scientist in the context of media coverage about climate change and genetically modified organisms. Using survey data from the United States, we find that political ideology and science knowledge affect who the US public believes is a scientist in these domains. Our results suggest important differences in the role of science media attention and science media selection in the publics “scientist” labeling. In addition, we replicate previous work and find that compared to other people who work in science, those with PhDs in Biology and Chemistry are most commonly seen as scientists.


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