scholarly journals Societal importance of Antarctic negative feedbacks on climate change: blue carbon gains from sea ice, ice shelf and glacier losses

2021 ◽  
Vol 108 (5) ◽  
Author(s):  
D. K. A. Barnes ◽  
C. J. Sands ◽  
M. L. Paulsen ◽  
B. Moreno ◽  
C. Moreau ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Multiple Stressors ◽  
Economic Benefits ◽  
Blue Carbon ◽  
Glacier Retreat ◽  
Indigenous Species ◽  
Carbon Sinks ◽  
Ice Shelf ◽  
Positive Feedbacks

AbstractDiminishing prospects for environmental preservation under climate change are intensifying efforts to boost capture, storage and sequestration (long-term burial) of carbon. However, as Earth’s biological carbon sinks also shrink, remediation has become a key part of the narrative for terrestrial ecosystems. In contrast, blue carbon on polar continental shelves have stronger pathways to sequestration and have increased with climate-forced marine ice losses—becoming the largest known natural negative feedback on climate change. Here we explore the size and complex dynamics of blue carbon gains with spatiotemporal changes in sea ice (60–100 MtCyear−1), ice shelves (4–40 MtCyear−1 = giant iceberg generation) and glacier retreat (< 1 MtCyear−1). Estimates suggest that, amongst these, reduced duration of seasonal sea ice is most important. Decreasing sea ice extent drives longer (not necessarily larger biomass) smaller cell-sized phytoplankton blooms, increasing growth of many primary consumers and benthic carbon storage—where sequestration chances are maximal. However, sea ice losses also create positive feedbacks in shallow waters through increased iceberg movement and scouring of benthos. Unlike loss of sea ice, which enhances existing sinks, ice shelf losses generate brand new carbon sinks both where giant icebergs were, and in their wake. These also generate small positive feedbacks from scouring, minimised by repeat scouring at biodiversity hotspots. Blue carbon change from glacier retreat has been least well quantified, and although emerging fjords are small areas, they have high storage-sequestration conversion efficiencies, whilst blue carbon in polar waters faces many diverse and complex stressors. The identity of these are known (e.g. fishing, warming, ocean acidification, non-indigenous species and plastic pollution) but not their magnitude of impact. In order to mediate multiple stressors, research should focus on wider verification of blue carbon gains, projecting future change, and the broader environmental and economic benefits to safeguard blue carbon ecosystems through law.

scholarly journals Correction to: Societal importance of Antarctic negative feedbacks on climate change: blue carbon gains from sea ice, ice shelf and glacier losses

2021 ◽  
Vol 108 (6) ◽  
Author(s):  
D. K. A. Barnes ◽  
C. J. Sands ◽  
M. L. Paulsen ◽  
B. Moreno ◽  
C. Moreau ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Blue Carbon ◽  
Ice Shelf ◽  
Negative Feedbacks

scholarly journals Climate change and glacier retreat drive shifts in an Antarctic benthic ecosystem

2015 ◽  
Vol 1 (10) ◽  
pp. e1500050 ◽  
Author(s):  
Ricardo Sahade ◽  
Cristian Lagger ◽  
Luciana Torre ◽  
Fernando Momo ◽  
Patrick Monien ◽  
...  
Keyword(s):  
Climate Change ◽  
Glacier Retreat ◽  
Sediment Runoff ◽  
Ice Shelf ◽  
Ecosystem Responses ◽  
Antarctic Species ◽  
Current Scenario ◽  
Antarctic Benthos ◽  
The Antarctic ◽  
Species Being

The Antarctic Peninsula (AP) is one of the three places on Earth that registered the most intense warming in the last 50 years, almost five times the global mean. This warming has strongly affected the cryosphere, causing the largest ice-shelf collapses ever observed and the retreat of 87% of glaciers. Ecosystem responses, although increasingly predicted, have been mainly reported for pelagic systems. However, and despite most Antarctic species being benthic, responses in the Antarctic benthos have been detected in only a few species, and major effects at assemblage level are unknown. This is probably due to the scarcity of baselines against which to assess change. We performed repeat surveys of coastal benthos in 1994, 1998, and 2010, analyzing community structure and environmental variables at King George Island, Antarctica. We report a marked shift in an Antarctic benthic community that can be linked to ongoing climate change. However, rather than temperature as the primary factor, we highlight the resulting increased sediment runoff, triggered by glacier retreat, as the potential causal factor. The sudden shift from a “filter feeders–ascidian domination” to a “mixed assemblage” suggests that thresholds (for example, of tolerable sedimentation) and alternative equilibrium states, depending on the reversibility of the changes, could be possible traits of this ecosystem. Sedimentation processes will be increasing under the current scenario of glacier retreat, and attention needs to be paid to its effects along the AP.

scholarly journals Coastal Scenic Beauty and Sensitivity at the Balearic Islands, Spain: Implication of Natural and Human Factors

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 456
Author(s):  
Alexis Mooser ◽  
Giorgio Anfuso ◽  
Lluís Gómez-Pujol ◽  
Angela Rizzo ◽  
Allan T. Williams ◽  
...  
Keyword(s):  
Climate Change ◽  
Economic Benefits ◽  
User Preferences ◽  
Balearic Islands ◽  
Future Climate Change ◽  
Sensitivity Index ◽  
Main Concern ◽  
Human Pressure ◽  
Continuous Increase ◽  
Scenic Beauty

Coastal areas globally are facing a significant range of environmental stresses, enhanced by climate change-related processes and a continuous increase of human activities. The economic benefits of tourism are well-known for coastal regions, but, very often, conflicts arise between short-term benefits and long-term conservation goals. Among beach user preferences, five parameters of greater importance stand out from the rest, i.e., safety, facilities, water quality, litter and scenery; the latter is the main concern of this study. A coastal scenic evaluation was carried out in the Balearic Islands and focused on two major issues: coastal scenic beauty together with sensitivity to natural processes and human pressure. The archipelago is renowned as a top international coastal tourist destination that receives more than 13.5 million visitors (2019). Impressive landscape diversity makes the Balearics Islands an ideal field for this research. In total, 52 sites, respectively located in Ibiza (11), Formentera (5), Mallorca (18) and Menorca (18), were field-tested. In a first step, coastal scenic beauty was quantified using the coastal scenic evaluation system (CSES) method, based on the evaluation of 26 physical and human parameters, and using weighting matrices parameters and fuzzy logic mathematics. An evaluation index (“D”) was obtained for each site, allowing one to classify them in one of the five scenic classes established by the method. Twenty-nine sites were included in class I, corresponding to extremely attractive sites (CSES), which were mainly observed in Menorca. Several sound measures were proposed to maintain and/or enhance sites’ scenic value. In a second step, scenic sensitivity was evaluated using a novel methodological approach that makes possible the assessment of three different coastal scenic sensitivity indexes (CSSI), i.e., the natural sensitivity index NSI, the human sensitivity index HSI and the total sensitivity index TSI. Future climate change trends and projection of tourism development, studied at municipality scale, were considered as correction factors. All the islands showed places highly sensitive to environmental processes, while sensitivity to human pressure was essentially observed at Ibiza and Mallorca. Thereafter, sites were categorized into one of three sensitive groups established by the methodology. Results obtained are useful in pointing out very sensitive sceneries as well as limiting, preventing and/or anticipating future scenic degradation linked to natural and human issues.

scholarly journals Response of ocean phytoplankton community structure to climate change over the 21st century: partitioning the effects of nutrients, temperature and light

2010 ◽  
Vol 7 (12) ◽  
pp. 3941-3959 ◽  
Author(s):  
I. Marinov ◽  
S. C. Doney ◽  
I. D. Lima
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Sea Ice ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
Vertical Mixing ◽  
Phytoplankton Community Structure ◽  
Marginal Sea ◽  
Small Phytoplankton ◽  
The Impact

Abstract. The response of ocean phytoplankton community structure to climate change depends, among other factors, upon species competition for nutrients and light, as well as the increase in surface ocean temperature. We propose an analytical framework linking changes in nutrients, temperature and light with changes in phytoplankton growth rates, and we assess our theoretical considerations against model projections (1980–2100) from a global Earth System model. Our proposed "critical nutrient hypothesis" stipulates the existence of a critical nutrient threshold below (above) which a nutrient change will affect small phytoplankton biomass more (less) than diatom biomass, i.e. the phytoplankton with lower half-saturation coefficient K are influenced more strongly in low nutrient environments. This nutrient threshold broadly corresponds to 45° S and 45° N, poleward of which high vertical mixing and inefficient biology maintain higher surface nutrient concentrations and equatorward of which reduced vertical mixing and more efficient biology maintain lower surface nutrients. In the 45° S–45° N low nutrient region, decreases in limiting nutrients – associated with increased stratification under climate change – are predicted analytically to decrease more strongly the specific growth of small phytoplankton than the growth of diatoms. In high latitudes, the impact of nutrient decrease on phytoplankton biomass is more significant for diatoms than small phytoplankton, and contributes to diatom declines in the northern marginal sea ice and subpolar biomes. In the context of our model, climate driven increases in surface temperature and changes in light are predicted to have a stronger impact on small phytoplankton than on diatom biomass in all ocean domains. Our analytical predictions explain reasonably well the shifts in community structure under a modeled climate-warming scenario. Climate driven changes in nutrients, temperature and light have regionally varying and sometimes counterbalancing impacts on phytoplankton biomass and structure, with nutrients and temperature dominant in the 45° S–45° N band and light-temperature effects dominant in the marginal sea-ice and subpolar regions. As predicted, decreases in nutrients inside the 45° S–45° N "critical nutrient" band result in diatom biomass decreasing more than small phytoplankton biomass. Further stratification from global warming could result in geographical shifts in the "critical nutrient" threshold and additional changes in ecology.

scholarly journals Climate Change in the Arctic—The Need for a Broader Gender Perspective in Data Collection

2021 ◽  
Vol 18 (2) ◽  
pp. 628
Author(s):  
Arja Rautio ◽  
Natalia Kukarenko ◽  
Lena Maria Nilsson ◽  
Birgitta Evengard
Keyword(s):  
Climate Change ◽  
Data Collection ◽  
Human Health ◽  
Economic Benefits ◽  
Theoretical Background ◽  
The Arctic ◽  
Gender Analysis ◽  
Roles And Responsibilities ◽  
Disaggregated Data

Climate change in the Arctic affects both environmental, animal, and human health, as well as human wellbeing and societal development. Women and men, and girls and boys are affected differently. Sex-disaggregated data collection is increasingly carried out as a routine in human health research and in healthcare analysis. This study involved a literature review and used a case study design to analyze gender differences in the roles and responsibilities of men and women residing in the Arctic. The theoretical background for gender-analysis is here described together with examples from the Russian Arctic and a literature search. We conclude that a broader gender-analysis of sex-disaggregated data followed by actions is a question of human rights and also of economic benefits for societies at large and of the quality of services as in the health care.

scholarly journals Vulnerability of the North Water ecosystem to climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sofia Ribeiro ◽  
Audrey Limoges ◽  
Guillaume Massé ◽  
Kasper L. Johansen ◽  
William Colgan ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Late Holocene ◽  
Sediment Cores ◽  
Arctic Ecosystems ◽  
Little Auk ◽  
The North ◽  
Water Ecosystem ◽  
North Water

AbstractHigh Arctic ecosystems and Indigenous livelihoods are tightly linked and exposed to climate change, yet assessing their sensitivity requires a long-term perspective. Here, we assess the vulnerability of the North Water polynya, a unique seaice ecosystem that sustains the world’s northernmost Inuit communities and several keystone Arctic species. We reconstruct mid-to-late Holocene changes in sea ice, marine primary production, and little auk colony dynamics through multi-proxy analysis of marine and lake sediment cores. Our results suggest a productive ecosystem by 4400–4200 cal yrs b2k coincident with the arrival of the first humans in Greenland. Climate forcing during the late Holocene, leading to periods of polynya instability and marine productivity decline, is strikingly coeval with the human abandonment of Greenland from c. 2200–1200 cal yrs b2k. Our long-term perspective highlights the future decline of the North Water ecosystem, due to climate warming and changing sea-ice conditions, as an important climate change risk.

scholarly journals Impact of abrupt sea ice loss on Greenland water isotopes during the last glacial period

2019 ◽  
Vol 116 (10) ◽  
pp. 4099-4104 ◽  
Author(s):  
Louise C. Sime ◽  
Peter O. Hopcroft ◽  
Rachael H. Rhodes
Keyword(s):  
Sea Ice ◽  
Temperature Increase ◽  
General Circulation ◽  
Ice Core ◽  
Circulation Model ◽  
Ice Cores ◽  
Nitrogen Isotope ◽  
Ice Shelf ◽  
Last Glacial Period ◽  
Precipitation Seasonality

Greenland ice cores provide excellent evidence of past abrupt climate changes. However, there is no universally accepted theory of how and why these Dansgaard–Oeschger (DO) events occur. Several mechanisms have been proposed to explain DO events, including sea ice, ice shelf buildup, ice sheets, atmospheric circulation, and meltwater changes. DO event temperature reconstructions depend on the stable water isotope (δ18O) and nitrogen isotope measurements from Greenland ice cores: interpretation of these measurements holds the key to understanding the nature of DO events. Here, we demonstrate the primary importance of sea ice as a control on Greenland ice coreδ18O: 95% of the variability inδ18O in southern Greenland is explained by DO event sea ice changes. Our suite of DO events, simulated using a general circulation model, accurately captures the amplitude ofδ18O enrichment during the abrupt DO event onsets. Simulated geographical variability is broadly consistent with available ice core evidence. We find an hitherto unknown sensitivity of theδ18O paleothermometer to the magnitude of DO event temperature increase: the change inδ18O per Kelvin temperature increase reduces with DO event amplitude. We show that this effect is controlled by precipitation seasonality.

Mapping vulnerability to multiple stressors: climate change and globalization in India

2004 ◽  
Vol 14 (4) ◽  
pp. 303-313 ◽  
Author(s):  
Karen O’Brien ◽  
Robin Leichenko ◽  
Ulka Kelkar ◽  
Henry Venema ◽  
Guro Aandahl ◽  
...  
Keyword(s):  
Climate Change ◽  
Multiple Stressors ◽  
Mapping Vulnerability

scholarly journals Coastal and river flood risk analyses for guiding economically optimal flood adaptation policies: a country-scale study for Mexico

2018 ◽  
Vol 376 (2121) ◽  
pp. 20170329 ◽  
Author(s):  
Toon Haer ◽  
W. J. Wouter Botzen ◽  
Vincent van Roomen ◽  
Harry Connor ◽  
Jorge Zavala-Hidalgo ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Flood Risk ◽  
Cost Benefit ◽  
Economic Benefits ◽  
Adaptation Strategies ◽  
Policy Implications ◽  
Flood Protection ◽  
Local Data ◽  
Flood Adaptation

Many countries around the world face increasing impacts from flooding due to socio-economic development in flood-prone areas, which may be enhanced in intensity and frequency as a result of climate change. With increasing flood risk, it is becoming more important to be able to assess the costs and benefits of adaptation strategies. To guide the design of such strategies, policy makers need tools to prioritize where adaptation is needed and how much adaptation funds are required. In this country-scale study, we show how flood risk analyses can be used in cost–benefit analyses to prioritize investments in flood adaptation strategies in Mexico under future climate scenarios. Moreover, given the often limited availability of detailed local data for such analyses, we show how state-of-the-art global data and flood risk assessment models can be applied for a detailed assessment of optimal flood-protection strategies. Our results show that especially states along the Gulf of Mexico have considerable economic benefits from investments in adaptation that limit risks from both river and coastal floods, and that increased flood-protection standards are economically beneficial for many Mexican states. We discuss the sensitivity of our results to modelling uncertainties, the transferability of our modelling approach and policy implications. This article is part of the theme issue ‘Advances in risk assessment for climate change adaptation policy’.

Early Holocene ocean conditions off the Zachariæ Isstrøm, Northeast Greenland

2021 ◽  
Author(s):  
Joanna Davies ◽  
Anders Møller Mathiasen ◽  
Kristiane Kristensen ◽  
Christof Pearce ◽  
Marit-Solveig Seidenkrantz
Keyword(s):  
Climate Change ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Atlantic Water ◽  
The Arctic ◽  
Future Climate Change ◽  
Polar Regions ◽  
Ice Shelf ◽  
Outlet Glacier ◽  
The Impact

&lt;p&gt;The polar regions exhibit some of the most visible signs of climate change globally; annual mass loss from the Greenland Ice Sheet (GrIS) has quadrupled in recent decades, from 51 &amp;#177; 65 Gt yr&lt;sup&gt;&amp;#8722;1&lt;/sup&gt; (1992-2001) to 211 &amp;#177; 37 Gt yr&lt;sup&gt;&amp;#8722;1&lt;/sup&gt; (2002-2011). This can partly be attributed to the widespread retreat and speed-up of marine-terminating glaciers. The Zachariae Isstr&amp;#248;m (ZI) is an outlet glacier of the Northeast Greenland Ice Steam (NEGIS), one of the largest ice streams of the GrIS (700km), draining approximately 12% of the ice sheet interior. Observations show that the ZI began accelerating in 2000, resulting in the collapse of the floating ice shelf between 2002 and 2003. By 2014, the ice shelf extended over an area of 52km&lt;sup&gt;2&lt;/sup&gt;, a 95% decrease in area since 2002, where it extended over 1040km&lt;sup&gt;2&lt;/sup&gt;. Paleo-reconstructions provide an opportunity to extend observational records in order to understand the oceanic and climatic processes governing the position of the grounding zone of marine terminating glaciers and the extent of floating ice shelves. Such datasets are thus necessary if we are to constrain the impact of future climate change projections on the Arctic cryosphere.&lt;/p&gt;&lt;p&gt;A multi-proxy approach, involving grain size, geochemical, foraminiferal and sedimentary analysis was applied to marine sediment core DA17-NG-ST8-92G, collected offshore of the ZI, on &amp;#160;the Northeast Greenland Shelf. The aim was to reconstruct changes in the extent of the ZI and the palaeoceanographic conditions throughout the Early to Mid Holocene (c.a. 12,500-5,000 cal. yrs. BP). Evidence from the analysis of these datasets indicates that whilst there has been no grounded ice at the site over the last 12,500 years, the ice shelf of the ZI extended as a floating ice shelf over the site between 12,500 and 9,200 cal. yrs. BP, with the grounding line further inland from our study site. This was followed by a retreat in the ice shelf extent during the Holocene Thermal Maximum; this was likely to have been governed, in part, by basal melting driven by Atlantic Water (AW) recirculated from Svalbard or from the Arctic Ocean. Evidence from benthic foraminifera suggest that there was a shift from the dominance of AW to Polar Water at around 7,500 cal. yrs. BP, although the ice shelf did not expand again despite of this cooling of subsurface waters.&lt;/p&gt;

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