Long-term legacy of delayed climate mitigation in global glacier response

2021 ◽  
Author(s):  
Fabien Maussion ◽  
Quentin Lejeune ◽  
Ben Marzeion ◽  
Matthias Mengel ◽  
David Rounce ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Greenhouse Gas ◽  
Sea Level ◽  
Climate Mitigation ◽  
Delayed Response ◽  
Glacier Change ◽  
Mountain Glaciers ◽  
Glacier Runoff ◽  
The Impact

<p>Mountain glaciers have a delayed response to climate change and are expected to continue to melt long after greenhouse gas emissions have stopped, with consequences both for sea-level rise and water resources. In this contribution, we use the Open Global Glacier Model (OGGM) to compute global glacier volume and runoff changes until the year 2300 under a suite of stylized greenhouse gas emission characterized by (i) the year at which anthropogenic emissions culminate, (ii) their reduction rates after peak emissions and (iii) whether they lead to a long-term global temperature stabilization or decline. We show that even under scenarios that achieve the Paris Agreement goal of holding global-mean temperature below 2 °C, glacier contribution to sea-level rise will continue well beyond 2100. Because of this delayed response, the year of peak emissions (i.e. the timing of mitigation action) has a stronger influence on mit-term global glacier change than other emission scenario characteristics, while long-term change is dependent on all factors. We also discuss the impact of early climate mitigation on regional glacier change and the consequences for glacier runoff, both short-term (where some basins are expected to experience an increase of glacier runoff) and long-term (where all regions are expecting a net-zero or even negative glacier contribution to total runoff), underlining the importance of mountain glaciers for regional water availability at all timescales.</p>

Sea-level rise and its possible impacts given a ‘beyond 4°C world’ in the twenty-first century

2011 ◽  
Vol 369 (1934) ◽  
pp. 161-181 ◽  
Author(s):  
Robert J. Nicholls ◽  
Natasha Marinova ◽  
Jason A. Lowe ◽  
Sally Brown ◽  
Pier Vellinga ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Temperature Rise ◽  
Full Range ◽  
Ice Sheets ◽  
Time Frame ◽  
First Century ◽  
Climate Mitigation ◽  
Twenty First Century ◽  
The Impact

The range of future climate-induced sea-level rise remains highly uncertain with continued concern that large increases in the twenty-first century cannot be ruled out. The biggest source of uncertainty is the response of the large ice sheets of Greenland and west Antarctica. Based on our analysis, a pragmatic estimate of sea-level rise by 2100, for a temperature rise of 4°C or more over the same time frame, is between 0.5 m and 2 m—the probability of rises at the high end is judged to be very low, but of unquantifiable probability. However, if realized, an indicative analysis shows that the impact potential is severe, with the real risk of the forced displacement of up to 187 million people over the century (up to 2.4% of global population). This is potentially avoidable by widespread upgrade of protection, albeit rather costly with up to 0.02 per cent of global domestic product needed, and much higher in certain nations. The likelihood of protection being successfully implemented varies between regions, and is lowest in small islands, Africa and parts of Asia, and hence these regions are the most likely to see coastal abandonment. To respond to these challenges, a multi-track approach is required, which would also be appropriate if a temperature rise of less than 4°C was expected. Firstly, we should monitor sea level to detect any significant accelerations in the rate of rise in a timely manner. Secondly, we need to improve our understanding of the climate-induced processes that could contribute to rapid sea-level rise, especially the role of the two major ice sheets, to produce better models that quantify the likely future rise more precisely. Finally, responses need to be carefully considered via a combination of climate mitigation to reduce the rise and adaptation for the residual rise in sea level. In particular, long-term strategic adaptation plans for the full range of possible sea-level rise (and other change) need to be widely developed.

scholarly journals Impact of Human Intervention and Sea Level Rise on Water-Logging Scenarios inside Polders-24 And 25 of Bangladesh

2022 ◽  
Vol 12 (3) ◽  
pp. 73-83
Author(s):  
Jamal M Haider ◽  
Haque M Aminul ◽  
Hossain Md Jahid ◽  
Haque Anisul
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Region ◽  
Storm Surges ◽  
Climate Change Scenarios ◽  
South Central ◽  
Water Logging ◽  
Natural Man ◽  
The Impact

Coastal region of Bangladesh possesses a fragile ecosystem and is exposed to hazards like cyclones, floods, storm surges, and water-logging. A detail understanding on the impact of water-logging due to various natural, man-made and climate change scenarios is still lacking. Considering this research gap, the present research is aimed to study impacts of these scenarios inside polders-24 and 25 which are situated on the western part of the coastal region. In this Study as natural scenario, sedimentation in the Hari River; as man-made scenario, new polders in the south-central region and as SLR scenario, an extreme sea level rise of 1.48m are considered. Long-term satellite images are analyzed, and numerical model is applied in the study area. The result shows that water-logging is more acute inside polder-25 compared to polder-24. Sedimentation in Hari River aggravates the water-logging condition. Dredging in Hari River does improve the situation. Journal of Engineering Science 12(3), 2021, 73-83

scholarly journals Long-term invasion dynamics of Spartina increase vegetation diversity and geomorphological resistance of salt marshes against sea level rise

2020 ◽  
Author(s):  
Dirk Granse ◽  
Sigrid Suchrow ◽  
Kai Jensen
Keyword(s):  
Salt Marsh ◽  
Species Diversity ◽  
Sea Level Rise ◽  
Sea Level ◽  
Salt Marshes ◽  
High Marsh ◽  
Marsh Vegetation ◽  
Vegetation Diversity ◽  
The Impact

AbstractThe cordgrass Spartina anglica C.E. Hubbard (Poaceae) is an invasive transformer in many salt marsh ecosystems worldwide. Relatively little is known about the capacity of Spartina to accelerate salt marsh succession and to protect salt marshes against sea level rise. We analyzed long-term changes in vegetation and elevation in mainland salt marshes of the European Wadden Sea in Schleswig-Holstein, Germany, to estimate the impact of non-native Spartina on the geomorphological resistance of salt marshes to sea level rise and on changes in species diversity. From 1989 to 2019, the Spartina-zone shifted and expanded upwards to elevations of the high marsh zone and Spartina increased in frequency in several salt marsh vegetation communities. At sites where Spartina dominated the vegetation already three decades ago, elevation and species diversity increased with a higher rate compared to sites lacking Spartina. The median change rates reached for elevation MHT +8.6 versus +1.5 mm per year, for species richness +3 versus $$\pm$$ ± 0 species per three decades, and for evenness +0.04 versus −0.08 per three decades, regarding plots with versus without former Spartina dominance, respectively. Invasion of salt marshes by Spartina and its continued, long-term presence were associated with increased elevation and species diversity in the face of sea level rise.

scholarly journals Future sea level rise constrained by observations and long-term commitment

2016 ◽  
Vol 113 (10) ◽  
pp. 2597-2602 ◽  
Author(s):  
Matthias Mengel ◽  
Anders Levermann ◽  
Katja Frieler ◽  
Alexander Robinson ◽  
Ben Marzeion ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Greenhouse Gas ◽  
Sea Level ◽  
Past Century ◽  
Intergovernmental Panel ◽  
Adaptation Measures ◽  
Equilibrium Response ◽  
Semiempirical Models

Sea level has been steadily rising over the past century, predominantly due to anthropogenic climate change. The rate of sea level rise will keep increasing with continued global warming, and, even if temperatures are stabilized through the phasing out of greenhouse gas emissions, sea level is still expected to rise for centuries. This will affect coastal areas worldwide, and robust projections are needed to assess mitigation options and guide adaptation measures. Here we combine the equilibrium response of the main sea level rise contributions with their last century's observed contribution to constrain projections of future sea level rise. Our model is calibrated to a set of observations for each contribution, and the observational and climate uncertainties are combined to produce uncertainty ranges for 21st century sea level rise. We project anthropogenic sea level rise of 28–56 cm, 37–77 cm, and 57–131 cm in 2100 for the greenhouse gas concentration scenarios RCP26, RCP45, and RCP85, respectively. Our uncertainty ranges for total sea level rise overlap with the process-based estimates of the Intergovernmental Panel on Climate Change. The “constrained extrapolation” approach generalizes earlier global semiempirical models and may therefore lead to a better understanding of the discrepancies with process-based projections.

scholarly journals Long-Term Regional Environmental Risk Assessment and Future Scenario Projection at Ningbo, China Coupling the Impact of Sea Level Rise

2019 ◽  
Vol 11 (6) ◽  
pp. 1560
Author(s):  
Yongjiu Feng ◽  
Qianqian Yang ◽  
Xiaohua Tong ◽  
Jiafeng Wang ◽  
Shurui Chen ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Environmental Risk ◽  
Socioeconomic Development ◽  
Principal Component ◽  
Storm Surges ◽  
Disaster Mitigation ◽  
Northern Coast ◽  
The Impact

Regional environmental risk (RER) denotes potential threats to the natural environment, human health and socioeconomic development caused by specific risks. It is valuable to assess long-term RER in coastal areas with the increasing effects of global change. We proposed a new approach to assess coastal RER considering spatial factors using principal component analysis (PCA) and used a future land use simulation (FLUS) model to project future RER scenarios considering the impact of sea level rise (SLR). In our study, the RER status was classified in five levels as highest, high, medium, low and lowest. We evaluated the 30 m × 30 m gridded spatial pattern of the long-term RER at Ningbo of China by assessing its 1975–2015 history and projecting this to 2020–2050. Our results show that RER at Ningbo has increased substantially over the past 40 years and will slowly increase over the next 35 years. Ningbo’s city center and district centers are exposed to medium-to-highest RER, while the suburban areas are exposed to lowest-to-medium lower RER. Storm surges will lead to strong RER increases along the Ningbo coast, with the low-lying northern coast being more affected than the mountainous southern coast. RER at Ningbo is affected principally by the combined effects of increased human activity, rapid population growth, rapid industrialization, and unprecedented urbanization. This study provides early warnings to support practical regulation for disaster mitigation and environmental protection.

Evidence of acceleration in regional sea-level rise in the North Sea

2021 ◽  
Author(s):  
Riccardo Riva ◽  
David Steffelbauer ◽  
Jos Timmermans ◽  
Jan Kwakkel ◽  
Mark Bakker
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
North Sea ◽  
Accurate Determination ◽  
Natural Variability ◽  
Reconstruction Technique ◽  
Tide Gauges ◽  
The Impact ◽  
Global Mean

<p>Tide gauges are the main source of information about sea-level changes in the Industrial Age. When looking at global mean values, century-long reconstructions produce rates between 1-2 mm/yr, while estimates over the last three decades reveal a much faster rise of about 3 mm/yr, as also indicated by satellite altimetry observations. In spite of this evidence for a recent acceleration, its quantification remains a challenging and relevant task, because results are highly dependent on the length of the record and on the reconstruction technique, whereas decision makers require clear proof to legitimise action. While global mean results are very important to understand climate change, regional to local variations are more relevant for the purpose of planning mitigation and adaptation measures. However, mainly due to natural variability, looking at individual tide gauge stations hampers the accurate determination of linear and non-linear trends.<br>We developed a time series analysis framework to determine whether SLR is accelerating by detecting the presence of a break-point in the long-term trend. We applied the framework to tide gauges in the southern North Sea, where several stations provide high-quality and uninterrupted records spanning more than a century (1890-2018). On average, coastal sea level rise increased from ~1.8 mm/yr over the first century of our study to ~2.8 mm/yr over the last 25 years, albeit with large inter-station differences. We performed several tests to assess the impact of natural variability on the observed trend changes and verified that stable break-points are only detected since the late 1970s, with the exact year depending on the chosen time-window. Therefore, we believe that the high sea-level rates observed over the last few decades are likely representing long-term changes.</p>

scholarly journals Attributing long-term sea-level rise to Paris Agreement emission pledges

2019 ◽  
Vol 116 (47) ◽  
pp. 23487-23492 ◽  
Author(s):  
Alexander Nauels ◽  
Johannes Gütschow ◽  
Matthias Mengel ◽  
Malte Meinshausen ◽  
Peter U. Clark ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Sea Level ◽  
21St Century ◽  
Paris Agreement ◽  
Mean Sea Level ◽  
Global Mean Sea Level ◽  
Global Mean

The main contributors to sea-level rise (oceans, glaciers, and ice sheets) respond to climate change on timescales ranging from decades to millennia. A focus on the 21st century thus fails to provide a complete picture of the consequences of anthropogenic greenhouse gas emissions on future sea-level rise and its long-term impacts. Here we identify the committed global mean sea-level rise until 2300 from historical emissions since 1750 and the currently pledged National Determined Contributions (NDC) under the Paris Agreement until 2030. Our results indicate that greenhouse gas emissions over this 280-y period result in about 1 m of committed global mean sea-level rise by 2300, with the NDC emissions from 2016 to 2030 corresponding to around 20 cm or 1/5 of that commitment. We also find that 26 cm (12 cm) of the projected sea-level-rise commitment in 2300 can be attributed to emissions from the top 5 emitting countries (China, United States of America, European Union, India, and Russia) over the 1991–2030 (2016–2030) period. Our findings demonstrate that global and individual country emissions over the first decades of the 21st century alone will cause substantial long-term sea-level rise.

Could climate engineering save the Greenland Ice Sheet?

2016 ◽  
Author(s):  
Patrick J. Applegate ◽  
K. Keller
Keyword(s):  
Sea Level Rise ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Sea Level ◽  
Computer Model ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Upper Atmosphere ◽  
Climate Engineering ◽  
Air Temperatures

Engineering the climate through albedo modification (AM) could slow, but probably would not stop, melting of the Greenland Ice Sheet. Albedo modification is a technology that could reduce surface air temperatures through putting reflective particles into the upper atmosphere. AM has never been tested, but it might reduce surface air temperatures faster and more cheaply than reducing greenhouse gas emissions. Some scientists claim that AM would also prevent or reverse sea-level rise. But, are these claims true? The Greenland Ice Sheet will melt faster at higher temperatures, adding to sea-level rise. However, it's not clear that reducing temperatures through AM will stop or reverse sea-level rise due to Greenland Ice Sheet melting. We used a computer model of the Greenland Ice Sheet to examine its contributions to future sea level rise, with and without AM. Our results show that AM would probably reduce the rate of sea-level rise from the Greenland Ice Sheet. However, sea-level rise would likely continue even with AM, and the ice sheet would not regrow quickly. Albedo modification might buy time to prepare for sea-level rise, but problems could arise if policymakers assume that AM will stop sea-level rise completely.

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