To calculate Sea Level Rise Risk, the following variable is used:
This risk is calculated only for sites within 30 km of sea and with altitude within 20 meters above sea level.
Sea Level Rise Risk analyzes hazard associated with permanent increase in mean sea level. This risk is based on absolute rise thresholds, representing long-term and largely irreversible changes.
The indicator directly assesses threat of permanent coastal flooding, accelerated erosion and increased frequency and severity of flooding during storm surges.
The methodology described for Sea Level Rise Risk assessment aligns with most recent scientific assessments and operational tools developed by world's major space and climate agencies.
The approach is robust because it is based on authoritative projection data and defines risk levels based on well-documented physical impact thresholds.
Impact descriptions for each risk level ('nuisance' flooding, erosion, saltwater intrusion, permanent flooding) are directly supported by IPCC report conclusions.
'Nuisance Flooding' concept, mentioned in lower risk levels, is technical term defined and monitored by operational agencies like NOAA.
In conclusion, our methodology is directly based on global scientific consensus data (IPCC AR6) and uses a risk scale whose thresholds and impact descriptions are fully coherent with scientific conclusions of IPCC and operational observations of agencies like NOAA.
The methodology described for Sea Level Rise Risk assessment aligns with most recent scientific assessments and operational tools developed by world's major space and climate agencies.
The approach is robust because it is based on authoritative projection data and defines risk levels based on well-documented physical impact thresholds. • NASA Sea Level Projection Tool This NASA online tool provides data directly from latest and most authoritative climate report: Sixth Assessment Report (AR6) of Intergovernmental Panel on Climate Change (IPCC). Using this tool means, in effect, using global scientific consensus data. The tool allows exploring SLR projections for different emission scenarios (SSP) and provides localized data accounting for vertical ground movements (subsidence or uplift). • Climate Change 2021: The Physical Science Basis Chapter 9 ('Ocean, Cryosphere and Sea Level Change') is comprehensive scientific document behind NASA tool data.
Impact descriptions for each risk level ('nuisance' flooding, erosion, saltwater intrusion, permanent flooding) are directly supported by IPCC report conclusions. • Special Report on the Ocean and Cryosphere in a Changing Climate • Climate Change 2022: Impacts, Adaptation and Vulnerability These reports are most comprehensive synthesis of expected sea level rise impacts. They confirm and scientifically document that: • Risk B and C (0.15 - 0.50 m): Few tens of centimeters rise causes exponential increase in extreme sea level event frequency. Events that historically occurred once per century could occur annually by century's end at many locations. This validates our descriptions of 'nuisance flooding' becoming common. • Risk D (0.50 - 1.00 m): This threshold is often cited as tipping point for many coastal areas. SROCC report highlights how at these levels saltwater intrusion becomes serious problem and existing coastal defenses begin to become inadequate. • Risk E and F (≥ 1.00 - 1.50 m): Exceeding 1 meter rise is considered point of no return for many small island states and coastal ecosystems. IPCC reports discuss how these SLR levels would trigger cascading impacts, population displacements and permanent loss of vast coastal areas, validating our 'High' and 'Very High' risk descriptions.
'Nuisance Flooding' concept, mentioned in lower risk levels, is technical term defined and monitored by operational agencies like NOAA. • NOAA Sea Level Rise Portal NOAA has established specific flood thresholds for US coasts. Their thresholds for 'minor flooding' (corresponding to nuisance flooding) are typically reached with sea level rise of about 0.3-0.5 meters above mean high tide. This provides independent operational validation for thresholds we defined in risk levels B and C, confirming that precisely at that SLR level flooding becomes perceptible and disruptive problem.
In conclusion, our methodology is directly based on global scientific consensus data (IPCC AR6) and uses a risk scale whose thresholds and impact descriptions are fully coherent with scientific conclusions of IPCC and operational observations of agencies like NOAA.