As many have noticed, Brazil and the Amazon basin have been experiencing a deepening drought over the last decades, but floods are five times more frequent than a hundred years ago. Intensifying flood events result in casualties, property and agricultural losses, and sea level rise is expected to increase their likelihood. 

Earth.Org takes a closer look.

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The Amazon River Delta is the largest in the world by quite a wide margin. It discharges a fifth of all ocean-bound freshwater into the Atlantic, more than the next seven largest rivers combined. The low-lying wetlands around the Amazon riverbed are incredibly rich in resources and biodiversity, and provide sustenance and livelihoods to around 1.5 million locals. 

Humans have often opted to develop communities around deltas, as they offer an interface between land, freshwater and the sea. The Amazon Delta is no exception, and the increasing pace of urbanization and commercial activities in the area are straining its natural resources and resilience. This is partly due to a massive influx of people from the more arid Northeast of Brazil, and other, less economically vibrant locations. While the Delta has seen less environmental degradation than other parts of the Amazon, the rapid development based around forestry and agroforestry has led to poorly developed urban settlements, sometimes lacking basic sanitation and infrastructure. 

As sea level rise increases the likelihood of intense floods, many of the aforementioned agglomerations will suffer heavy damage to what infrastructure they have, and their inhabitants will risk disease from poor sewage dissemination in the flood waters and mosquito proliferation.

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 3m; extreme = 5m). Population displacement indicated bottom right.

Sea Level Rise Methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

You might also like: Sea Level Rise by 2100 – The Persian Gulf

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

• Costa, Sandra Maria Fonseca da, Monique Bruna Silva do Carmo, and Paulo Roxo Barja. “The urban hierarchy at the delta of the Amazon River and the importance of small cities.” urbe. Revista Brasileira de Gestão Urbana 11 (2019).

Qatar and Bahrain, both found on the Persian Gulf, are extremely vulnerable to sea level rise. The bulk of their populations and commercial activities are stacked on their shorelines, and little effort has been expended to adapt to a rapidly changing environment. 

Earth.Org takes a closer look.

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The Kingdom of Bahrain consists of 40 islands with a small overall area of 767  km² and one of the highest population densities in the world at 1,700 persons per km². Most of its activity and population is concentrated on coastal areas that do not exceed 5 m elevation above sea level, and the highest point is only 134m high. As climate change progresses, more frequent and intense droughts are predicted to afflict Bahrain, but its greatest challenge is the slow advance of sea level rise. 

Based on the Intergovernmental Panel on Climate Change’s predictions, 1.5 m of sea level rise would submerge 27% of the Kingdom’s land area. This puts its urban, industrial, recreational and critical infrastructures at risk and forces decision-makers to design a comprehensive adaptation plan if they are to avoid insurmountable economic losses. 

Qatar is in a similar situation. It is experiencing rapid demographic growth in its mainly coastal urban areas, including its capital city Doha. The city’s most important political and economic sectors (West Bay, Al Corniche and Al Dafna) are all located on the shoreline, which makes sea level rise an extremely expensive problem. While storm surge and flash floods are rare here, over 18% of Qatar’s land area is low enough to be permanently reclaimed if the oceans rise 5m above pre-industrial levels. 

Both Bahrain and Qatar are facing economic challenges for the long run, as they must generate employment for its exploding young, educated population. A heavy dependence on few commodities like oil has made national budgets unstable, making it difficult to implement and stay committed to long-term plans. Unfortunately, sea level rise is a challenge that will span decades, and progressive yet steady work will be key to mitigating its effects. The UN provides many avenues to help fund and execute adaptation strategies, and these have historically been under-used by Arab countries. The onus is on them to begin reaching out and committing their thoughts, time and money to solving a problem that cares little for political and economical issues. 

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 1m; extreme = 3m). Population displacement indicated bottom right.

Sea Level Rise Methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

You might also like: Sea Level Rise by 2100 – The Persian Gulf

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

• Laurent A. Lambert, Cristina D’Alessandro (2019). Climate Change, Sea Level Rise, and Sustainable Urban Adaptation in Arab Coastal Cities. Middle East Institute.

Kuwait’s eponymous capital city is located on the Persian Gulf, and concentrates most of the country’s population, culture, economy and decision making. Like the rest of the Gulf, it is highly vulnerable to sea level rise, and it may have to work with its neighbors to fend off the swelling waters. 

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Though considered arable, the Kuwait inner ranges are quite inhospitable, and much of the country’s oil-based trade goes through maritime channels. It is considered a maritime and mercantile country, and is highly dependent on the coastal zone for its drinking water, fisheries, water cooling for power plants and recreation. In fact, the bulk of its urban, commercial and industrial infrastructure is located near the shoreline, as is 90% of its population. 

Kuwait natural freshwater resources are very limited. It is an arid country, with high temperatures and evaporation rates, and low humidity and precipitation rates, with no surface water bodies. Desalination plants provide most of the drinking water, which is heavily subsidized, thus encouraging irresponsible usage and waste. The largest source of water for industrial and agricultural use is the groundwater reserve, which has been excessively pumped and whose quality is deteriorating. This is due to saltwater intrusion, and return of pumped up irrigation water with fertilizers and pesticides. 

Near the northern shores of Kuwait is a small group of islands, the largest of which is called Bubiyan island. An uninhabited salt marsh, its lies very low and faces full submersion within the next few decades. It serves as an important rest area for migratory birds on the Turkey-India, and the Eurasia-Africa routes. 

Earth.Org has modelled sea level rise from Kuwait City northward to illustrate the need for a rapid decarbonization. 

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 1m; extreme = 3m). Population displacement indicated bottom right.

Sea Level Rise Methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

You might also like: Sea Level Rise by 2100 – The Persian Gulf

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

• AlAli, E. H. “Groundwater history and trends in Kuwait.” WIT Transactions on Ecology and the Environment 112 (2008): 153-164.

• El Raey, Mohamed. “Impact of sea level rise on the Arab Region.” University of Alexandria. Arab Academy of Science, Technology, and Maritime (2010).

The countries of the Persian Gulf are highly arid and dependent on groundwater reserves to fend of drought and water scarcity. Further, cities and critical infrastructures are often found on the coast, and this combination makes the area extremely vulnerable to sea level rise. 

Earth.Org takes a closer look.

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Article adapted and reposted from Carboun.com, written by Karim Elgendy. 

As the last ice age ended, the earth’s climate began to warm up, glaciers and ice sheets started to melt, and sea levels rose globally. With sea levels rising, seawater (once again) flooded into the Gulf (also known as the Persian Gulf or Arabia Gulf), whose sea floor was exposed for millennia and covered in sand dunes (except for lakes and the Tigris-Euphrates river meandering across it towards the Arabian sea).

Sea levels rose by 125 meters until they peaked 1 – 2 meters above today’s levels, 4,000–5,000 years ago. They then dropped to the present levels and settled for the last 2500 years.

But since the beginning of the 20th century the world witnessed a new type of sea level rise, driven by Climate Change caused by human activity. Seas rose by 0.16-0.21 meters between 1900-2016 and are set to rise much faster if current trends continue. Naturally, the low-lying coastal areas around the Gulf are at risk again. The only difference being that we have now built cities and infrastructure on them.

To protect these investments and communities living there, we must mitigate further climate change by cutting our Carbon Emissions enough to meet the 1.5 degree target.

Cities of the region must also collaborate to develop a pan-regional comprehensive resilience strategy that protects their built environment, their infrastructure, and the future of the next generations who would like to call this region home.

In order to illustrate the need for action, Earth.Org has modelled what extreme sea level rise could look like in the Persian Gulf by the end of the century.

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 1m; extreme = 3m). Population displacement indicated bottom right.

Sea Level Rise Methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

You might also like: Sea Level Rise by 2100 – New York City

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

Amsterdam and the rest of the Netherlands have learnt to co-exist with water bodies, implementing sophisticated flood control systems over the last 50 years. However, sea level rise is projected to overrun the barriers and drainage systems, meaning Amsterdam will have to invest and adapt to avoid severe flooding.

Earth.Org has mapped the extreme flooding Amsterdam could experience by 2100.

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The Netherlands has been dealing with floods for hundreds of years, and has learnt to handle them. After a 1953 flood killed nearly 2000 people, a massive network of dams and levees was built. Indeed, 26% percent of the country is below sea level, and many agglomerations are built around water bodies with flood potential. 

From dikes, dams and floodgates to floodable amenities like the Water Square Berthemplein and salt-tolerant crops, the Netherlands has the most sophisticated water control systems in the world. In fact, most experts in the field selling their services to places at risk, like Bangladesh, are Dutch. 

Despite this, the infrastructure in place today cannot protect Amsterdam forever. Meteorologists from Utrecht University say that a long term, controlled withdrawal will have to be considered. This is because the area and population that rising sea levels will put at risk would require unimaginable investment and work to protect. 

Earth.Org has modelled what some of these future extreme flooding scenarios could look like in Amsterdam by 2100.

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 2m; extreme = 4m). Population displacement indicated bottom right.

Methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

You might also like: Sea Level Rise by 2100 – New York City

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

Heavy rainfall and overflowing rivers cause frequent floods in Côte d’Ivoire, costing around US $1.2 billion per year. Coastal erosion and sea level rise are set to amplify the damage in the next few decades, and the country must prepare if they are to mitigate this. 

Earth.Org has mapped what extreme flooding could look like by 2100 to illustrate the need for action.

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Sea level rise is occurring faster than the global average around West Africa, menacing under-developed areas with the additional burden of regular flooding. The impacts of such events are many, be it damage to houses, infrastructure and valuable ecosystems, or aquifer and crop contamination with salt water or the propagation of water-borne disease through sewage overflow. 

Erosion is also a major factor in determining how fast the ocean reclaims land. Parts of the West African coast have been eroding at a shocking 1.8 m per year as a result of natural and human influences. Sea level rise and regular wave mechanics slowly gnaw away at the shores, but unregulated sand mining and the destruction of natural flood barriers such as mangroves are more deplorable causes. 

The city of Abidjan could find some of its critical infrastructures, such as ports and hospitals, inundated and damaged before long, and the construction of a 260 m seawall is unlikely to do much. Temporary respite could come from the nearby Comoe River and Grand Bassam lagoon. The river usually carries large amounts of silt down to the shore and helps prevent erosion, but recently, silt has clogged its outlet into the sea, diverting its water into the lagoon. Attempts have been made to open channels to the ocean, but these are always rapidly filled up again. 

Officials have stated that it would cost US $30 million to build a stable canal, which is quite costly for a temporary solution. The urgent need for protection has been brought up with the International Union for the Conservation of Nature (IUCN), and consensus is that natural barriers such as mangroves and coastal dunes may be the best option at the moment.

The lack of longer-term solutions is not reassuring for a country whose capital could face some disastrous flooding by the end of the century. Earth.Org has mapped such an event to illustrate the need for action. 

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 1m; extreme = 3m). Population displacement indicated bottom right.

Sea level rise mapping methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

Mapping by Braundt Lau. Article written by Owen Mulhern. 

You might also like: Sea Level Rise by 2100 – Miami

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

Vancouver has drafted a plan to stave sea level rise away, but they have yet to carry it out. Ice sheet melts magnified by Vancouver’s strong winter downpours result in frequent and damaging floods. 

Earth.Org plotted the flooding risk Vancouver could suffer by 2100 according to the current sea level rise rate.

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Situated in the Burrard Peninsula, Vancouver is bordered by bodies of water where regions located in the lower mainland are at the highest risk of sinking. Population growth requires urban expansion, further increasing flood risk. Compared to the historical Fraser River flood 1984, what lies ahead could be catastrophic. Forecasts have estimated a total of 250,000 people displaced and US $30 billion in damages by 2100.

Vancouver’s flood control system was recently evaluated and 74 dikes proved to be too weak to go against future floods. The frequency of 1-in-100 year and 1-in-200 year floods could increase up to ten-fold in the next few decades, driving officials to undertake the Coastal Adaptation Plan (CAP) to strengthen the infrastructure. This plan has yet to begin, despite being announced nearly two years ago. While a task of this scale is difficult to implement, a sense of urgency is not alarmist at this point but rational. 

As a call for awareness, Earth.Org has mapped what extreme flooding would look like in Vancouver by 2100 if no action were taken.

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 3m; extreme = 5m). Population displacement indicated bottom right.

Sea level rise mapping methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

Mapping by Braundt Lau. Article written by Eva Angla Seputra and Owen Mulhern. 

You might also like: Sea Level Rise by 2100 – Miami

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

Accelerating sea level rise, coastal erosion and subsiding land is putting the agglomeration around Houston at risk of regular flooding in the next few decades. The state of Texas recognizes the danger faced by Houston and is planning to invest US $12 billion in preventive measures.

Earth.org takes a closer look.

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The combination of high tides and sea level rise is already increasing flood risk in the city of Houston. Between 2005 and 2017, homes in the Texas Gulf Coast lost more than US $76 million in value due to tidal floods alone, not including hurricane risk. A historic flood hit the city in September of 2019, and rescue forces were called upon to perform over a thousand water rescues. 

Slightly higher sea levels can make a big difference in extreme storm surge occurrence. A 1-in-100 year flooding event (whose intensity has a 1% chance of occurring in any given year) could become a 1-in-10 year flood by 2050. This is made worse by land subsidence due to excessive groundwater extraction, a widespread problem in Texas. After Hurricane Harvey incurred US $127 billion in damages in Houston, state officials decided to invest over US $12 billion in sea level rise solutions, including storm surge protection, drainage and erosion control. 

While the right measures are being taken in Texas, other states and countries may not have the means to mount an adequate response. Earth.Org has mapped what flooding would look like around Houston by 2100 if not action were taken.

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 2m; extreme = 5m). Population displacement indicated bottom right.

Sea level rise mapping methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

Mapping by Braundt Lau. Article written by Owen Mulhern. 

You might also like: Sea Level Rise by 2100 – Miami

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

The Commonwealth of the North Mariana Islands (CNMI) is an island chain located in the western Pacific. Saipan, the archipelago’s main island, is identified as critically vulnerable to sea level rise and changes in rainfall patterns by the CNMI Climate Change Working Group. Sea level around the islands is expected to rise by more than 1 metre by 2100, which puts the majority of the islands’ low lying areas at high risk.

Earth.Org has mapped what extreme flooding could look like by 2100 to illustrate the need for action.

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CNMI consists of 15 islands, which are the northernmost islands in the Mariana Archipelago. The majority of the population resides on the islands of Saipan, Tinian and Rota, with Saipan being the largest in terms of size. Sea level has been rising in CNMI at a rate of about 7.62 mm per year, which is more than twice the global average, with an expected 1 m by the end of the century. 

Saipan is an important location of CNMI, out of 53,883 permanent residents, 52,263 of them live on Saipan. Its western coastal plain is composed of natural habitat, residential neighbourhoods and the primary business district of Garapan. A vulnerability assessment was done by the CNMI Climate Change Working Group and the result identified nearly all of the villages and resources in the area as being critically vulnerable to sea-level rise and changes in rainfall patterns. Around 80% of the coast is expected to be inundated using the projection of 0.91 metres of sea level rise, which could force mass relocation inland or off the islands. 

Earth.Org has mapped what severe flooding could look like on Saipan by 2100 to illustrate. 

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 1m; extreme = 3m). Population displacement indicated bottom right.

Sea level rise mapping methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

Mapping by Braundt Lau. Article written by Wing Ki Leung and Owen Mulhern. 

You might also like: Sea Level Rise by 2100 – Miami

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.

Wallis and Futuna is a French overseas territory located midway between New Caledonia and Tahiti. A study has shown that several hundred seaside homes in Uvea, central island of the Wallis archipelago, would have to be evacuated with as little as 50 cm of sea level rise. 

Earth.Org has mapped what extreme flooding could look like by 2100 to illustrate the need for preparation.

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Wallis and Futuna does not face an immediate threat of submersion, but it still faces serious challenges due to climate change. Composed of two distinct archipelagos, the Wallis and the Horn archipelagos, the French overseas collectivity is home to around 14,000 residents. Most of whom reside in and near the islands’ low-lying coastal zones. 

A study led by the Secretariat of the Pacific Regional Environmental Programme (Sprep) used a model to illustrate the potential submersion of Uvea, central island of the Wallis archipelago; it used a range from 0.5 to 3 metres sea level rise. The result was alarming, with only 0.5 metres of sea level rise, several hundreds of seaside homes in the area would be under threat. Coastal erosion can already be observed, chipping away at beaches and uprooting coastal vegetation. Other impacts include aquifer contamination and crop failure, along with damage to critical infrastructure like ports, roads and hospitals. 

To combat erosion, several measures have been implemented at a local level, for example, shoring up the seafront, installation for sea walls and planting erosion-resistant vegetation. However, these initiatives are just local and temporary solutions, a long-term protection against the significant sea level rise is still not found.

Earth.Org has mapped the worst case scenario floods the islands could experience as a call to action. 

Sea level rise projections by 2100 for two scenarios with the amount of rise in meters indicated (mild = 2m; extreme = 4m). Population displacement indicated bottom right.

Sea level rise mapping methodology

Global mean sea level is projected to rise by 2m at the end of this century. However, in order to determine local sea level rise (SLR), one has to take into account local coastal flood levels which could be 2.8m above Mean Higher-High Water (MHHW) at extreme forecasts. These local levels bring variability to the projected SLR from 1m to 6.5m (eg. Rio vs Kolkata).

The SLR scenarios used in this study are based on the forecasts from Climate Central – Coastal Risk Screening Tool  with the following parameters:

• Sea level Projection Source
• Coastal Flood Level
• Pollution Scenario
• Luck

Sea level Projection Source:

From two highly cited journals by Kopp et al., estimating SLR mainly due to ocean thermal expansion and ice melt. The mid-range scenario projected 0.5-1.2m of SLR based on different representative concentration pathways (RCP) defined by the IPCC. While the pessimistic scenario added more mechanisms of ice-sheet melting, estimating SLR at 1m-2.5m in 2100, with a projection of 10m SLR at 2300.

Coastal Flooding

More frequent coastal flooding is a direct impact of sea-level rise. Based on the Global tides and surge reanalysis by Muis et al., (2016), it is estimated that the extreme coastal water level could be from 0.2 – 2.8m over the mean level. While in extreme cases like China and the Netherlands it could experience 5-10m of extreme sea levels. Here, the coastal local flood level is added on top of the projected SLR.

Pollution Scenario:

Allows choosing the RCP, the greenhouse gas concentration trajectory defined by the IPCC.  The mild level is based on RCP4.5, of 2°C temperature rise; while the Extreme level is based on RCP 8.5, of 4°C temperature rise.

Luck:

Applies to the baseline SLR, defined in the “Sea level projection” section, upon which we add flooding. “Mild” refers to the mid-range scenario of 0.5-1.2m, and “extreme” to the pessimistic scenario of 1-2.5m. We used the high-end value of each scenario (mild = 1m; extreme = 2.5m).

Mapping by Braundt Lau. Article written by Wing Ki Leung and Owen Mulhern. 

You might also like: Sea Level Rise by 2100 – Miami

References:

• Kulp, Scott A., and Benjamin H. Strauss. “New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding.” Nature communications 10.1 (2019): 1-12.

• Florczyk, A. J., Corbane, C., Ehrlich, D., Freire, S., Kemper, T., Maffenini, L., Melchiorri, M., Politis, P., Schiavina, M., Sabo, F. & Zanchetta, L. (2019). GHSL Data Package 2019 Public Release.

• Kopp, R. E., DeConto, R. M., Bader, D. A., Hay, C. C., Horton, R. M., Kulp, S., Oppenheimer, M., Pollard, D. & Strauss, B. H. (2017). Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections. Earth’s Future, 5(12), 1217–1233.

• Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J., Strauss, B. H. & Tebaldi, C. (2014). Probabilistic 21st and 22nd Century Sea-Level Projections at a Global Network of Tide-Gauge Sites. Earth’s Future, 2(8), 383–406.

• Kulp, S. A. & Strauss, B. H. (2019). New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications, 10(1), 4844. Retrieved June 21, 2020, from http://www.nature.com/articles/s41467-019-12808-z

• Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. (2016). A Global Reanalysis of Storm Surges and Extreme Sea Levels. Nature Communications, 7.