Questions

• What is sea level rise and what causes it?
• What are the expected impacts of sea level rise on Sausalito?
• I live well above Richardson Bay, why should I care about sea level rise?
• What is known about the amount and timing of sea level rise in Sausalito?
• What has Sausalito already done to start planning for sea level rise?
• How can we plan for rising seas in Sausalito if the level and timing are not known precisely?
• What are the benefits of preparing now for sea level rise?
• What options do coastal communities have for adapting to sea level rise?
• What tools has the Sea Level Rise Task Force created?
• What are the key next steps for Sausalito's SLR planning efforts?
• Why are regional collaborations a core principle of all sea level rise planning?

What is sea level rise and what causes it?

Sea level rise is an increase in the level of the world's oceans due to the effects of global warming. The average global sea level has risen 8 inches in the last century, and the rate has increased over recent decades.^[1] Even if greenhouse gas emissions are reduced and the earth stops warming, the sea levels will continue to rise for centuries.^[2]

Global warming is causing the global (average) sea level to rise in two major ways. First, glaciers and ice sheets worldwide are melting and adding water to the ocean. Second, the volume of the ocean is expanding as the water warms. A third, much smaller contributor to sea level rise is a decline in the amount of liquid water on land—aquifers, lakes and reservoirs, rivers, soil moisture. This shift of liquid water from land to ocean is largely due to groundwater pumping.  

What are the expected impacts of sea level rise on Sausalito?

Even a small amount of sea level rise can have devastating effects on coastal communities like Sausalito, leading to flooding, erosion, water table elevation, and lost habitat for fish, birds, and plants. Destructive flooding and erosion alone could affect homes, businesses, roads, the sewer system, stormwater drainage, and other infrastructure. From flooding at Gate 5 road and the North 101 on-ramp, to erosion at Swede’s Beach and Tiffany Beach, there are multiple signs that Sausalito is currently being impacted by rising water levels.^[3]

Bay Area scientists have analyzed the most current sea level rise data along with the conditions in Sausalito and in a 2017 BayWAVE report^[4] identified the following as our most critical vulnerabilities:

• The sewer and stormwater infrastructure that serves all residences and businesses in Sausalito is vulnerable. The sewer pipes are susceptible to increasing water infiltration, risking overburdening the wastewater treatment facility, while the pump stations along Bridgeway are threatened by flooding. As for the stormwater pipes, which empty directly into the Bay using gravity, rising waters could cause them to back up and flood inland areas.
• The primary transportation system and circulation routes in Sausalito are vulnerable, affecting both normal flow and evacuation routes. This creates safety concerns by impacting ingress, egress and access for both emergency personnel and members of the public. For example, the Bridgeway transportation corridor in Old Town, Downtown, and New Town are vulnerable to flooding. In addition, northern access to Highway 101 could become flooded, redirecting traffic to the narrow winding hillside roads.
• A number of shoreline restaurants, hotels, residences, and businesses are vulnerable to permanent flooding.
• The ferry landing and parking lot are vulnerable, putting public transit for commuters, residents, and tourists at risk.
• Many of Sausalito’s shoreline parks and beaches will flood during storms and will be susceptible to shoreline erosion. In recent years, Tiffany Beach and Swede’s Beach have become extremely narrow, a preview of what could happen to other recreational areas.
• Parts of the Marinship could experience permanent water inundation, impacting many businesses and marine services. This area currently floods during storms and high tides, and the flooding will become worse, eventually leading to permanent inundation.

To get a feeling of what permanent sea level rise could look like in the future, walk around Sausalito during king tides. These tides occur 6-8 times each year, and are 1-2 feet higher than average daily high tides that already cause temporary flooding on Bridgeway at 101 and in the Marinship. King tides help us understand what Sausalito would look like given the 1-2 feet of permanent water inundation that is expected during the next few decades.

I live well above Richardson Bay, why should I care about sea level rise?

Although much of the housing in Sausalito is well above current sea level, many City services and infrastructure are located in areas that will be inundated by water if adaptation measures are not implemented. The sewer system, stormwater system, and major access routes are essential to our community’s public health, safety and economy. The main sewer pipes, for example, are located underneath Bridgeway and are vulnerable to sea level rise, especially in the low lying areas of Old Town through which almost all wastewater flows.

In order for Sausalito to be livable—whether it be on a houseboat, near Caledonia, or high on the hill—we must increase the resilience of our infrastructure. In addition, sea level rise must become integrated with our disaster preparedness planning, as key evacuation routes could become flooded during storm surge, king tides, or El Niño events.
 

What is known about the amount and timing of sea level rise in Sausalito?

What Is Known
Data shows that the sea level in San Francisco has risen eight inches between 1900 and 2000, and that this rise has accelerated 2.5x since then.^[5]

Of course, the amount and timing of future SLR is not known precisely but scientists have created SLR models to project a range of sea levels based on current and future global warming. These projections will continue to improve as scientific understanding increases and as the impacts of local, state, national and global policy choices play out.

• From now until 2050, differences in sea-level rise projections from various models and under different emissions scenarios are relatively minor. For the San Francisco area, we should expect a 1-2 foot rise in water levels.
• After 2050, sea-level rise projections increasingly depend on the trajectory of greenhouse gas emissions and the rate of ice sheet loss, thus there are a wide range of projections. For the San Francisco area, we should expect anywhere from 2.5 - 7 foot rise in waters.

Key Unknown Factors
Only a range of sea level increases can be projected because the exact amount depends on two major unknown factors:

• The level of future greenhouse gas emissions. The degree of global warming, thus sea level rise, depends on how much global society can “bend the curve” to lower greenhouse gas emissions. Our current and near-term energy and transportation choices can definitely slow but not stop climate change and sea level rise.
• The rates of ice sheet loss and glacier melt due to global warming. The ice sheets in Antarctica and Greenland, which hold 98% of the world's land ice, could melt slowly, or there could be a major chaotic collapse which defies precise prediction. Note that sea-based or floating ice (e.g., icebergs and the north pole) do not directly contribute to sea level rise, just as the melting of floating ice cubes does not overflow a glass of water.

Global Average SLR Projections
The scientists at the National Oceanic and Atmospheric Administration (NOAA) categorize their global average SLR projections in five paths from a low sea level (small increase in temperature and rate of ice sheet loss) to a high sea level (high increase in temperature and rate of ice sheet loss).^[6] The diagram below plots NOAA’s range of global projections along a vertical scale in meters.

 

Sausalito Projections and Probabilities

The global average sea level rise slightly differs from what will happen locally in Sausalito, based on local conditions such as subsidence, ocean currents, and whether the land is still rebounding from the compressive weight of Ice Age glaciers. For Sausalito, we can expect the following:^[7]

• 0.5 - 0.8 feet of sea level rise by 2030
• 1.1 - 1.9’ by 2050
• 2.4 - 6.9’ by 2100

To help interpret those numbers, the low end of the range reflects a likely case of 66% probability, which that should be applied to lower-stakes decisions (e.g., planning for parks where rising waters may not be too impactful). The high end of the range reflects a 0.05% chance of occurring, which should be considered for higher-stakes decisions (e.g., planning for infrastructure that must have a decades-long lifespan, where additional rising waters could be catastrophic).

An engineering analogy can help explain the rationale behind using the high end of the range in certain high-stakes decision-making. When a bridge is being designed, the steel is not engineered just to meet the likely load requirements. Rather, the engineers start with the maximum number of cars and trucks at their maximum possible weight. Then they add an additional factor of safety, sometimes double that projected load. We need to do a similar thing with sea level rise planning: when the stakes are high, we need to plan for the worst case and possibly even an extra safety factor. Even though this possibility has less of a chance of actually happening, extra prudence is a valid and sound approach for reasonably ensuring public safety.

Projections of future sea-level rise, especially under high emissions scenarios, have increased substantially over the last few years, primarily due to new and improved understanding of continental ice sheet loss.

What has Sausalito already done to start planning for sea level rise?

Sausalito has already completed some of the groundwork for SLR planning although there is still much work to do. For example, the Sausalito General Plan (ratified in January 2021 by the City Council), elevated the critical nature of SLR by weaving considerations of rising seas into the Programs, Policies, and Objectives of the General Plan. This clearly articulated the community’s long-term commitment to address sea level rise through meaningful adaptations.

Going back a bit in history, Sausalito’s Sustainability Commission created the 2015 Climate Action Plan to focus the “mitigation” of climate change (including sea level rise) by reducing our greenhouse gas emissions (the Climate Plan informed several portions of the 2021 General Plan). Currently, the Sustainability Commission has focused its important work on promoting electric vehicle usage, the electrification of homes, and several other programs to reduce Sausalito’s greenhouse gases through our near-term energy and transportation choices.

But even if greenhouse gas emissions are reduced and the earth stops warming, the sea levels will continue to rise for centuries.^[8] Members of the community recognized that SLR was already having direct, significant impacts on Sausalito’s infrastructure and a concentrated effort was needed. Thus the City Council created the Sea Level Rise Task Force in April 2021 to focus on “adaptation," and begin to chart the path towards adapting to the reality of sea level rise based on the direction set by the General Plan. Importantly, grant-making organizations clearly differentiate between grants to mitigate climate change and grants to adapt to sea level rise, further justifying our community’s separate efforts on these two critical fronts.

The SLR Task Force has built on the themes and priorities in the General Plan, and in November 2021 delivered a Sea Level Rise Report and Recommendations with immediate, medium-term and long-term recommended actions. This report is based on the best available science, data, and hours of meetings and interviews with industry experts, regulators, academics, and researchers. It outlines a course of action for the City of Sausalito by highlighting immediate, medium, and long-term opportunities to address the impacts of sea level rise.

How can we plan for rising seas in Sausalito if the level and timing are not known precisely?

Historical data shows that sea level is rising, and rising at an increasing rate. Scientists have high confidence in the projected range of sea level rise between now and 2050. Sausalito will have to adapt to rising seas because even if global greenhouse gas emissions go down to zero, the waters will continue to rise for centuries. Thus we need to start planning for higher water levels now, and plan in a manner that accommodates uncertain timing for specific sea levels. Instead of planning based on a specific year (e.g., 2030), most SLR plans being developed around the world are based on amounts of sea level rise (e.g., 1 foot) or particular triggers (e.g., flooding of Bridgeway twice a year).

This type of plan, called an Adaptation Pathway,^[9] addresses uncertainty in SLR projections, and allows for flexibility and adjustment over time. Adaptation Pathways involve a decision-making process with a sequence of manageable steps and decision-points (based on SLR amount or triggers). When those decision points are reached we would look to deploy the next level of adaptation.

To illustrate the structure of an adaptation pathway, imagine an important but low-lying road. In the short term, city planners could opt to construct a horizontal levee that protects the road to some degree, but then once the sea level rises 10” or the road floods more than 3 times a year (the trigger), another adaptation measure must be used. Perhaps elevating the road would be the best option at this point. In this example, planners chose an adaptation pathway that implements several different options, the first being a low-regret short-term option that preserves additional options for an uncertain future. The road is then monitored and certain signals would trigger the next adaptation measure. Thus a city can plan and adapt without being concerned with specific time frames.

To help with planning, Marin County has selected six sea level rise scenarios, based on three levels of permanent sea-level rise (10”, 20”, 60”) plus temporary storm surge (SS) for each.^[10] Those three paired levels (10” and 10”+SS, 20” and 20”+SS, 60” and 60”+SS) are being used for planning in the near-, middle- and long-term throughout the Bay Area. One can think of the three paired time frames as roughly equating to 2030, 2050, and 2100.^[11] These six scenarios are the basis for visualizing sea level rise in Sausalito’s interactive SLR map. By having common scenarios and a common language, Sausalito can plan effectively and in concert with our neighbors, especially those in Richardson Bay.

Waiting for scientific certainty on the degree of sea level rise before making plans is neither a safe nor prudent option. As with earthquakes, we need to plan for rising water without knowing the specific timing or magnitude. Projections of sea-level rise over the next three decades can inform preparedness efforts, adaptation actions, and hazard mitigation that can be undertaken today—which will prevent much greater losses in the future than if action is not taken. Consideration of high and even extreme sea levels in decisions with implications past 2050 is needed to safeguard the people and assets of Sausalito, Marin County, and all coastal California.

What are the benefits of preparing now for sea level rise?

As a waterfront community, Sausalito is extremely vulnerable to sea level rise. Rising waters will impact a wide range of policy decisions and programs in Sausalito, including infrastructure, housing, circulation, transportation, land uses, and economic growth. While projections on the amount and timing of sea level rise are not definitive, Sausalito will save time, money and heartache by preparing now.

Sausalito has the opportunity to act now to proactively address critical infrastructure and public safety issues by developing an assessment of the vulnerabilities related to SLR; evaluating a range of adaptation measures; pursuing Regional, State, and Federal funding opportunities; and engaging in regional collaborations specifically related to sea level rise.

The general benefits to acting now regarding SLR preparations include:^[12]

• Planning ahead means adaptation actions can be strategic and phased. Early planning can allow Sausalito to adopt a phased approach that calls for escalating actions when certain predetermined conditions or “triggers” are reached.
• Acting now can “buy time” before more significant responses are needed. Putting certain adaptation projects and strategies in place now can help postpone and extend the period before which subsequent, more difficult-to-implement actions are needed.
• Early implementation allows us to test approaches and learn what works best. Acting sooner rather than later will let us monitor, evaluate, and revise certain adaptations in the coming years before SLR threats become more critical.
• Taking action earlier may make overall adaptation efforts more affordable. Undertaking a multiyear, multistep strategic plan for SLR adaptation can allow us to spread costs over a longer period of time.
• The coming decade is a key window for SLR preparation. Some adaptation strategies—such as fortifying certain tidal marshes—may not be effective against SLR unless they are implemented before the Bay rises to higher levels.

Long-term planning to protect against higher water levels involves projects with long lead times, greater financing needs, and more coordination—all of which require earlier start times. The earlier we get started planning for rising seas, the more effective our adaptation actions will be, the less impact they may have on our flora and fauna and people, and the more fiscally responsible we will be as a community.

Significant rise in the sea level is not something we are going to see in the next few years so there is no need for immediate alarm—but we can’t use this as an excuse not to do anything for 10-20 years. The buildings and infrastructure that we build today should be informed by what we know today about significant sea level rise that is coming in the next few decades.  

What options do coastal communities have for adapting to Sea Level Rise?

Coastal communities like Sausalito have a broad variety of options for adapting to sea level rise, several of which may be deployed simultaneously. Much work needs to be done to determine exactly which adaptations are best for our community based on our unique site characteristics, specific vulnerabilities, priorities, budget, and current technology. This involves a years-long planning process heavily influenced by stakeholder engagement.

To date, scientists, engineers, and planners have identified several categories of adaptations, each with pros and cons:

• “Grey” infrastructure involves engineering adaptations such as seawalls, levees, pump stations, riprap, tidal gates. In general, these protection measures may only last for a few decades, because at some point in the future SLR will exceed the design parameters of the engineered solutions.
• “Green” infrastructure involves nature-based adaptations primarily to prevent shoreline erosion through grasses/oyster beds, wetlands conversion, levees with wetlands transition zones. In the long run, these protection measures will only mitigate king tides and storm surges, and do not mitigate permanent Sea Level Rise.
• Accommodation measures involve lifestyle adaptations such as elevating structures above future tides, floodable and floatable developments (floating homes).
• Avoidance measures involve restricting development through local zoning/permitting changes, while Retreat measures involve removing structures and infrastructure and/or relocating them to higher locations thus allowing lands to become fully or partially inundated.

Sausalito may need to simultaneously deploy several types of adaptations. The best adaptations will cover several of our priority vulnerabilities, be cost effective, be accepted by the community, last for decades, and be extensible. When we produce an initial SLR Adaptation Plan, it will be continuously revised and updated based on unfolding conditions, updated projections, past experience, and community input. Thus the exact adaptations we deploy will most likely evolve over time.

What tools has the Sea Level Rise Task Force created?

The goal of the Sea Level Rise Task Force has been to create basic tools that City staff and the community can use in an on-going SLR effort whose end goal would be to create an Sea Level Rise Adaptation Plan (which most coastal communities in the United States are already working on). Those tools include:

• SLR Website: the foundation of communication and engagement with the community at large, including frequently asked questions, task force updates, the interactive map, and further educational resources.
• Interactive Sea Level Rise Map:^[13] This interactive map enables residents to explore how the six SLR scenarios will affect the city, including our wastewater and storm drain infrastructure. You can specify a sea level scenario, scroll through town, zooming in and out, and turn specific layers off and on to show only the information you want to see. You can also specify a street address to focus on a particular property—and its vulnerability to critical parts of Sausalito infrastructure, namely our stormwater network and wastewater treatment system.
• A Vulnerability Assessment in spreadsheet format that characterizes Sausalito's assets (e.g., infrastructure, residences, businesses) according to various SLR criteria (e.g., height above sea level, sensitivity to rising waters, adaptive capacity). Based on the County of Marin’s 2017 Vulnerability Assessment for Sausalito,^[14] local knowledge and more detail has been added while significant gaps in knowledge are highlighted. This vulnerability assessment will be the basis for all future SLR adaptation planning.
• Opportunities for nature-based adaptations and potential pilot projects including California Coastal Conservancy plan to include Dunphy Park in a SF Restoration Authority proposal for a living shorelines project.
• A Sea Level Rise Adaptation Planning Methodology based on best practices,^[15] which involves assessing our major vulnerabilities, identifying adaptation options, and laying out adaptation pathways (phased adaptations of major vulnerabilities based on amounts of sea level rise).
• Compilation of Marin County network and collaboration opportunities with key scientists and governmental organizations.
• A high-level Communications Plan for involving the community in long-range SLR planning. Highlights include key stakeholders, goals, and strategies to inform and engage the community.
• A preliminary set of funding mechanisms involving grants and opportunities such as geologic hazard abatement districts.
• An annotated bibliography of resources (e.g., scientific articles, technical reports, other community’s adaptation plans, government guidance).

What are the key next steps for Sausalito’s SLR planning efforts?

The Sea Level Rise Task Force has taken the first steps in our Sea Level Rise Adaptation Planning Methodology, and that process should continue (see below). The overarching goals are to assess vulnerabilities and identify adaptation options, all the while engaging stakeholders to ensure community feasibility, with the end product being an Adaptation Plan.  To move this process forward, the Task Force has recommended that the City Council allocate budget and resources, while more fully engaging the broader Sausalito community in sea level rise issues.

Specifically, the Sea Level Rise Task Force recommended that the City of Sausalito undertake the following immediate steps:

1. Approve funding to complete the vulnerability assessment and adopt the CalOES criteria to assess vulnerabilities.
2. Apply a SLR planning lens to infrastructure and other planning priorities, including the Capital Improvement Program.
3. Hire to eliminate silos, create partnerships and pursue grant funding around sea level rise.
4. Approve funding and staff time for communications and public outreach including a statistically significant survey and website updates.

The end result of the SLR Adaptation Planning process will be a set of adaptation actions structured as “Adaptation Pathways.” Our Adaptation Plan will include individual adaptation pathways for each priority vulnerable asset (for example, the Sewer System adaptation pathway might be different from the Transportation System adaptation pathway although they could share common elements). Moving forward, the initial SLR Adaptation Plan will be continuously revised and updated based on unfolding conditions, updated projections, past experience, and community input

Engaging with community stakeholders and our neighbors (including Marin City and Tam Junction) is a critical part of the process. In addition, the City would be remiss if it did not account for the potential impacts of its planning on climate justice, economic needs and social disparities in our community and along our coastline.

Why are regional collaborations a core principle of all sea level rise planning?

Rising waters do not respect city boundaries, thus broad SLR adaptation can only be achieved through collaborative action. It is critical that Sausalito work with our neighbors in Richardson Bay and around the entire San Francisco Bay. We live in a highly networked region where impacts in one area (and responses to them) have cascading effects. We can also benefit from the scientific expertise and practical experiences of other communities around the Bay.

Sausalito's adaptation actions could have unintended, cascading negative impacts on our neighbors. For example, researchers have found that constructing a seawall along the southern tip of the Bay near San Jose would increase flooding in the northern tip near Napa—a city about 60 miles away.^[16] On a smaller scale, a sea wall on one property can severely negatively affect a neighboring unprotected property due to accelerated beach loss.^[17]

Sausalito’s current collaborative efforts involve coordinating among our neighboring communities in Richardson Bay via the BayWAVE Southern Marin working group which includes Marin City, Tam Valley, Mill Valley, and Belvedere and Tiburon. We anticipate additional regional dialogue as a result of the cooperative efforts detailed in the recent Bay Adapt Regional Strategy for a Rising Bay. Collective action can be expedited by shared goals that help communities find and enact their own solutions. No one agency, jurisdiction or community can or should handle sea level rise alone.

Further Information

Other ways to learn more about SLR effects upon our fair city:

• Refer to informative Resources in order to do a deep dive into the subjects surrounding Sea Level Rise. For example, you can learn more about global warming’s influence on sea level projections and different strategies for adapting to SLR.
• Check back to this FAQ page, as we will be adding more questions and answers on a regular basis.

Footnotes

^[1] National Oceanic and Atmospheric Administration, Is Sea Level Rising? https://oceanservice.noaa.gov/facts/sealevel.html , (accessed 12 September 2021)

^[2] BayWAVE, Marin Shoreline Sea Level Rise Vulnerability Assessment, 2017, pg 164 (accessible through the MarinCounty.org website).

^[3] Per the Sausalito Landslide Task Force Report and Recommendation (2019), this impact may be the result of sea level rise, subsidence, or both.

^[4] BayWAVE, Marin Shoreline Sea Level Rise Vulnerability Assessment, 2017, pg 164 (accessible through the MarinCounty.org website).

^[5] From 1900 to 2000 the waters rose a steady 0.08 inch per year, while from 2000 to 2020 they accelerated to a 0.2 inch per year increase (a 2.5x increase). Sea Level Rise Vulnerability and Consequences Assessment (2020), Chapter 2: Sea Level Rise Climate Science and Scenarios. City and County of San Francisco.

^[6] Climate Change: Global Sea Level, April 2022, NOAA, (accessed 9 November 2022)

^[7] The experts at California Legislative Analysis Office have provided these projections for San Francisco, whose Presidio tide gauge is the closest to Sausalito. This would not reflect any hyper-local additional perceived sea level rise due to subsidence, for example. Refer to the following for more detail: Summary of LAO Report Preparing for Rising Seas: How the State Can Help Support Local Coastal Adaptation Efforts, California Legislative Analysts Office, December 2019.

^[8] IPCC, 2021, Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (Summary for Policymakers). Section B.5.4

^[9] Adaptation pathways are widely recommended by regional and national experts (e.g, San Francisco Estuary Institute and National Oceanic and Atmospheric Administration) as the appropriate structure for an Adaptation Plan.

^[10] Marin County’s Sea Level Rise Model Comparison Memo provides details on why these 6 scenarios were chosen.

^[11] The actual projected ranges published by the State of California for permanent SLR in San Francisco are 6”-9.6” in 2030, 13.2”-22.8” for 2050, 28.8”-82.8” for 2100.

^[12] Preparing for Rising Seas: How the State Can Help Support Local Coastal Adaptation Efforts. California Legislative Analyst’s Office, December 2019, Figure 8.

^[13] The Sausalito SLR interactive map combines Lidar data (laser-based remote sensing data) with the OCOF (CoSMoS/Our Coast Our Future) sea level rise model from the USGS. Rather than relying on historic flooding and storm records, CoSMoS uses wind and pressure from global climate models to project coastal storms under changing climatic conditions during the 21st century.

^[14] BayWAVE, Marin Shoreline Sea Level Rise Vulnerability Assessment, 2017, pg 164 (accessible through the MarinCounty.org website).

^[15] The Task Force synthesized a five-step planning process based upon the best aspects of three respected methodologies: BCDC’s Bay Adapt Regional Strategy for a Rising Bay (“Bay Adapt”, finalized October 2021), the 5-step NOAAs process specific to Coastal Adaptation Planning and the more general California Adaptation Planning Guide for Climate Resilience put out by the Governor's Office on Emergency Services  (Cal OES). Sea Level Rise Adaptation Planning is an emerging field and there are no "established methodologies" or "industry standards". As data, experience, and knowledge evolve then Sausalito's thinking, methodologies, and solutions will have to evolve also.

^[16] Economic evaluation of sea-level rise adaptation strongly influenced by hydrodynamic feedbacks. Michelle A. Hummel, Robert Griffin, Katie Arkema, Anne D. Guerry. Proceedings of the National Academy of Sciences Jul 2021, 118 (29) e2025961118; DOI: 10.1073/pnas.2025961118

^[17] Brucal, A., Lynham, J. Coastal armoring and sinking property values: the case of seawalls in California. Environmental Economics and Policy Studies 23, 55–77 (2021). https://doi.org/10.1007/s10018-020-00278-3