scholarly journals Ocean ventilation and deoxygenation in a warming world: introduction and overview

2017 ◽  
Vol 375 (2102) ◽  
pp. 20170240 ◽  
Author(s):  
John G. Shepherd ◽  
Peter G. Brewer ◽  
Andreas Oschlies ◽  
Andrew J. Watson
Keyword(s):  
Climate Change ◽  
Ocean Circulation ◽  
Economic Consequences ◽  
Oxygen Solubility ◽  
Ocean Ventilation ◽  
Wide Range ◽  
Indirect Impacts ◽  
Warming World ◽  
Ventilation Rates ◽  
Oral Presentations

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’.

scholarly journals High-latitude ocean ventilation and its role in Earth's climate transitions

2017 ◽  
Vol 375 (2102) ◽  
pp. 20160324 ◽  
Author(s):  
Alberto C. Naveira Garabato ◽  
Graeme A.  MacGilchrist ◽  
Peter J. Brown ◽  
D. Gwyn Evans ◽  
Andrew J. S. Meijers ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
High Latitude ◽  
Climate System ◽  
High Latitudes ◽  
Overturning Circulation ◽  
Ocean Ventilation ◽  
Earth’S Climate ◽  
Warming World ◽  
Climate Transitions

The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered. This article is part of the themed issue ‘Ocean ventilation and deoxygenation in a warming world’.

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

2017 ◽  
Vol 375 (2102) ◽  
pp. 20160327 ◽  
Author(s):  
Andrew Bakun
Keyword(s):  
Climate Change ◽  
Coastal Upwelling ◽  
Dead Zone ◽  
Small Pelagic Fish ◽  
Ocean Ventilation ◽  
The Us ◽  
Warming World ◽  
Gill Raker ◽  
Interannual Scale ◽  
Ocean Deoxygenation

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’.

scholarly journals Multivariate Sub-Regional Ocean Indicators in the Mediterranean Sea: From Event Detection to Climate Change Estimations

2021 ◽  
Vol 8 ◽  
Author(s):  
Mélanie Juza ◽  
Joaquín Tintoré
Keyword(s):  
Climate Change ◽  
Mediterranean Sea ◽  
Ocean Circulation ◽  
Heat Waves ◽  
Mesoscale Eddy ◽  
Value Added ◽  
Policy Decision ◽  
Balearic Islands ◽  
Wide Range ◽  
The Mediterranean

The increasing science and society requests for ocean monitoring from global to regional and local scales, the need for integration and convergence into a globally consistent ocean observing system as well as the need for improvement of access to information are now internationally recognized goals to progress toward the sustainable management of a healthy ocean. To respond to these challenges at regional level, the Balearic Islands Coastal Observing and Forecasting System (SOCIB) is developing a comprehensive set of ocean indicators in the Mediterranean Sea and around the Balearic Islands, key environments that are strongly affected by climate change and human pressure. This new SOCIB value-added product addresses the sub-regional ocean variability from daily (events) to interannual/decadal (climate) scales. A user-friendly interface has been implemented to monitor, visualize and communicate ocean information that is relevant for a wide range of sectors, applications and regional end-users. These sub-regional indicators allowed us to detect specific events in real time. Remarkable events and features identified include marine heat waves, atmospheric storm, extreme river discharge, mesoscale eddy, deep convection among others, all of them being oceanic phenomena that directly impact the ocean circulation and marine ecosystems. The long-term variations, in response to climate change, are also addressed highlighting and quantifying trends in physical and biogeochemical components of the ocean as well as sub-regional differences. At both (sub-) regional, national and international levels, a society-aligned science will have stronger impact on policy decision-makings and will support society to implement specific actions to address worldwide environmental challenges.

scholarly journals Implications of climate change for agricultural productivity in the early twenty-first century

2010 ◽  
Vol 365 (1554) ◽  
pp. 2973-2989 ◽  
Author(s):  
Jemma Gornall ◽  
Richard Betts ◽  
Eleanor Burke ◽  
Robin Clark ◽  
Joanne Camp ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Agricultural Productivity ◽  
Climate Change Impacts ◽  
Global Scale ◽  
Climate Projections ◽  
Pests And Diseases ◽  
Early Twenty ◽  
Wide Range ◽  
Indirect Impacts

This paper reviews recent literature concerning a wide range of processes through which climate change could potentially impact global-scale agricultural productivity, and presents projections of changes in relevant meteorological, hydrological and plant physiological quantities from a climate model ensemble to illustrate key areas of uncertainty. Few global-scale assessments have been carried out, and these are limited in their ability to capture the uncertainty in climate projections, and omit potentially important aspects such as extreme events and changes in pests and diseases. There is a lack of clarity on how climate change impacts on drought are best quantified from an agricultural perspective, with different metrics giving very different impressions of future risk. The dependence of some regional agriculture on remote rainfall, snowmelt and glaciers adds to the complexity. Indirect impacts via sea-level rise, storms and diseases have not been quantified. Perhaps most seriously, there is high uncertainty in the extent to which the direct effects of CO 2 rise on plant physiology will interact with climate change in affecting productivity. At present, the aggregate impacts of climate change on global-scale agricultural productivity cannot be reliably quantified.

A MODELING SYSTEM FOR CLIMATE CHANGE RISK ASSESSMENT, MANAGEMENT AND HEDGING IN COASTAL AREAS

2017 ◽  
Author(s):  
Sergei Soldatenko ◽  
Sergei Soldatenko ◽  
Genrikh Alekseev ◽  
Genrikh Alekseev ◽  
Alexander Danilov ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Coastal Areas ◽  
Mitigation Strategies ◽  
System Structure ◽  
The Arctic ◽  
Risk Modeling ◽  
Wide Range ◽  
Adverse Weather ◽  
The Impact

Every aspect of human operations faces a wide range of risks, some of which can cause serious consequences. By the start of 21st century, mankind has recognized a new class of risks posed by climate change. It is obvious, that the global climate is changing, and will continue to change, in ways that affect the planning and day to day operations of businesses, government agencies and other organizations and institutions. The manifestations of climate change include but not limited to rising sea levels, increasing temperature, flooding, melting polar sea ice, adverse weather events (e.g. heatwaves, drought, and storms) and a rise in related problems (e.g. health and environmental). Assessing and managing climate risks represent one of the most challenging issues of today and for the future. The purpose of the risk modeling system discussed in this paper is to provide a framework and methodology to quantify risks caused by climate change, to facilitate estimates of the impact of climate change on various spheres of human activities and to compare eventual adaptation and risk mitigation strategies. The system integrates both physical climate system and economic models together with knowledge-based subsystem, which can help support proactive risk management. System structure and its main components are considered. Special attention is paid to climate risk assessment, management and hedging in the Arctic coastal areas.

The Biology of Mediterranean-Type Ecosystems

2018 ◽  
Author(s):  
Karen J. Esler ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Invasive Species ◽  
Habitat Loss ◽  
Endemic Species ◽  
Geographic Area ◽  
Cutting Edge ◽  
Wide Range ◽  
The Mediterranean ◽  
Mediterranean Type Ecosystems

The world’s mediterranean-type climate regions (including areas within the Mediterranean, South Africa, Australia, California, and Chile) have long been of interest to biologists by virtue of their extraordinary biodiversity and the appearance of evolutionary convergence between these disparate regions. Comparisons between mediterranean-type climate regions have provided important insights into questions at the cutting edge of ecological, ecophysiological and evolutionary research. These regions, dominated by evergreen shrubland communities, contain many rare and endemic species. Their mild climate makes them appealing places to live and visit and this has resulted in numerous threats to the species and communities that occupy them. Threats include a wide range of factors such as habitat loss due to development and agriculture, disturbance, invasive species, and climate change. As a result, they continue to attract far more attention than their limited geographic area might suggest. This book provides a concise but comprehensive introduction to mediterranean-type ecosystems. As with other books in the Biology of Habitats Series, the emphasis in this book is on the organisms that dominate these regions although their management, conservation, and restoration are also considered.

scholarly journals Stomatal conductance limited the CO2 response of grassland in the last century

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Juan C. Baca Cabrera ◽  
Regina T. Hirl ◽  
Rudi Schäufele ◽  
Andy Macdonald ◽  
Hans Schnyder
Keyword(s):  
Climate Change ◽  
Stomatal Conductance ◽  
Nitrogen Nutrition ◽  
Physiological Control ◽  
Co2 Response ◽  
Nitrogen Acquisition ◽  
Wide Range ◽  
Park Grass Experiment ◽  
Conductance Changes ◽  
Canopy Stomatal Conductance

Abstract Background The anthropogenic increase of atmospheric CO2 concentration (ca) is impacting carbon (C), water, and nitrogen (N) cycles in grassland and other terrestrial biomes. Plant canopy stomatal conductance is a key player in these coupled cycles: it is a physiological control of vegetation water use efficiency (the ratio of C gain by photosynthesis to water loss by transpiration), and it responds to photosynthetic activity, which is influenced by vegetation N status. It is unknown if the ca-increase and climate change over the last century have already affected canopy stomatal conductance and its links with C and N processes in grassland. Results Here, we assessed two independent proxies of (growing season-integrating canopy-scale) stomatal conductance changes over the last century: trends of δ18O in cellulose (δ18Ocellulose) in archived herbage from a wide range of grassland communities on the Park Grass Experiment at Rothamsted (U.K.) and changes of the ratio of yields to the CO2 concentration gradient between the atmosphere and the leaf internal gas space (ca – ci). The two proxies correlated closely (R2 = 0.70), in agreement with the hypothesis. In addition, the sensitivity of δ18Ocellulose changes to estimated stomatal conductance changes agreed broadly with published sensitivities across a range of contemporary field and controlled environment studies, further supporting the utility of δ18Ocellulose changes for historical reconstruction of stomatal conductance changes at Park Grass. Trends of δ18Ocellulose differed strongly between plots and indicated much greater reductions of stomatal conductance in grass-rich than dicot-rich communities. Reductions of stomatal conductance were connected with reductions of yield trends, nitrogen acquisition, and nitrogen nutrition index. Although all plots were nitrogen-limited or phosphorus- and nitrogen-co-limited to different degrees, long-term reductions of stomatal conductance were largely independent of fertilizer regimes and soil pH, except for nitrogen fertilizer supply which promoted the abundance of grasses. Conclusions Our data indicate that some types of temperate grassland may have attained saturation of C sink activity more than one century ago. Increasing N fertilizer supply may not be an effective climate change mitigation strategy in many grasslands, as it promotes the expansion of grasses at the disadvantage of the more CO2 responsive forbs and N-fixing legumes.

scholarly journals Incorrect Asian aerosols affecting the attribution and projection of regional climate change in CMIP6 models

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Zhili Wang ◽  
Lei Lin ◽  
Yangyang Xu ◽  
Huizheng Che ◽  
Xiaoye Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Radiative Forcing ◽  
Impact Analysis ◽  
Climate Model ◽  
Regional Climate ◽  
Eastern China ◽  
Coupled Model ◽  
Regional Climate Change ◽  
Anthropogenic Aerosol ◽  
Wide Range

AbstractAnthropogenic aerosol (AA) forcing has been shown as a critical driver of climate change over Asia since the mid-20th century. Here we show that almost all Coupled Model Intercomparison Project Phase 6 (CMIP6) models fail to capture the observed dipole pattern of aerosol optical depth (AOD) trends over Asia during 2006–2014, last decade of CMIP6 historical simulation, due to an opposite trend over eastern China compared with observations. The incorrect AOD trend over China is attributed to problematic AA emissions adopted by CMIP6. There are obvious differences in simulated regional aerosol radiative forcing and temperature responses over Asia when using two different emissions inventories (one adopted by CMIP6; the other from Peking university, a more trustworthy inventory) to driving a global aerosol-climate model separately. We further show that some widely adopted CMIP6 pathways (after 2015) also significantly underestimate the more recent decline in AA emissions over China. These flaws may bring about errors to the CMIP6-based regional climate attribution over Asia for the last two decades and projection for the next few decades, previously anticipated to inform a wide range of impact analysis.

scholarly journals A potential feedback loop underlying glacial-interglacial cycles

2021 ◽  
Author(s):  
Els Weinans ◽  
Anne Willem Omta ◽  
George A. K. van Voorn ◽  
Egbert H. van Nes
Keyword(s):  
Ocean Circulation ◽  
Feedback Loop ◽  
Atmospheric Temperature ◽  
Earth System ◽  
Biological Productivity ◽  
Ocean Ventilation ◽  
The Earth ◽  
Main Driver ◽  
Underlying Mechanisms ◽  
Convergent Cross Mapping

AbstractThe sawtooth-patterned glacial-interglacial cycles in the Earth’s atmospheric temperature are a well-known, though poorly understood phenomenon. Pinpointing the relevant mechanisms behind these cycles will not only provide insights into past climate dynamics, but also help predict possible future responses of the Earth system to changing CO$$_2$$ 2 levels. Previous work on this phenomenon suggests that the most important underlying mechanisms are interactions between marine biological production, ocean circulation, temperature and dust. So far, interaction directions (i.e., what causes what) have remained elusive. In this paper, we apply Convergent Cross-Mapping (CCM) to analyze paleoclimatic and paleoceanographic records to elucidate which mechanisms proposed in the literature play an important role in glacial-interglacial cycles, and to test the directionality of interactions. We find causal links between ocean ventilation, biological productivity, benthic $$\delta ^{18}$$ δ 18 O and dust, consistent with some but not all of the mechanisms proposed in the literature. Most importantly, we find evidence for a potential feedback loop from ocean ventilation to biological productivity to climate back to ocean ventilation. Here, we propose the hypothesis that this feedback loop of connected mechanisms could be the main driver for the glacial-interglacial cycles.

scholarly journals Group Facilitation on Societal Disruption and Collapse: Insights from Deep Adaptation

2021 ◽  
Vol 13 (11) ◽  
pp. 6280
Author(s):  
Jem Bendell ◽  
Katie Carr
Keyword(s):  
Climate Change ◽  
Environmental Degradation ◽  
First Person ◽  
Group Facilitation ◽  
Environmental Destruction ◽  
Difficult Conversations ◽  
Radical Uncertainty ◽  
Direct And Indirect Impacts ◽  
Indirect Impacts

This article synthesises the practice and rationale behind ways of facilitating gatherings on topics of societal disruption and collapse, which is argued to be useful for lessening damaging responses. The authors draw on first-person inquiry as facilitators of gatherings, both online and in person, in the post-sustainability field of ‘Deep Adaptation,’ particularly since 2018. This term describes an agenda and framework for people who believe in the probable, inevitable or unfolding collapse of industrial consumer societies, due to the direct and indirect impacts of human-caused climate change and environmental degradation. Some of the principles of Deep Adaptation facilitation are summarised, such as containment, to enable co-responsibility for a safe enough space for difficult conversations. Another key principle is welcoming radical uncertainty in response to the anxieties that people feel from their anticipation of collapse. A third principle is making space for difficult emotions, which are welcomed as a natural and ongoing response to our predicament. A fourth aspect is a curiosity about processes of othering and separation. This paper provides a review of the theories that a reason for environmental destruction is the process of othering people and nature as being less significant or meaningful. One particular modality called Deep Relating is outlined.

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