Item O5 0.5
� � �, BOARD OF COUNTY COMMISSIONERS
County of Monroe � ��r�i
�r � s�� Mayor Heather Carruthers,District 3
The Florida.Keys Mayor Pro Tem Michelle Coldiron,District 2
Craig Cates,District 1
David Rice,District 4
Sylvia J.Murphy,District 5
County Commission Meeting
April 15, 2020
Agenda Item Number: 0.5
Agenda Item Summary #6592
BULK ITEM: Yes DEPARTMENT: Sustainability
TIME APPROXIMATE: STAFF CONTACT: Rhonda Haag (305) 453-8774
N/A
AGENDA ITEM WORDING: Approval to accept the updated Unified Regional Sea Level Rise
Projections (2020) of the Southeast Florida Regional Climate Change Compact and direct staff to
utilize the updated projections as the basis for sea level rise adaptation planning activities.
ITEM BACKGROUND: Board action is necessary to formally accept the updated Unified
Regional Sea Level Rise Projection (2019) of the Southeast Florida Regional Climate Change
Compact.
This action provides the Board with a sea level rise projection and support document to guide risk
assessments and sea level rise adaptation planning county-wide and in coordination with the region
of southeast Florida.
The Southeast Florida Regional Climate Change Compact (Compact), updates the Unified Regional
Sea Level Rise Projection at least every 5 years to provide ongoing and current guidance for
regionally consistent sea level rise adaptation planning and decision-making. The Compact
published the first Unified Regional Sea Level Rise (SLR) Projection for Southeast Florida in 2011
and updated the projection in 2015. The 2019 projection, the Compact's third Unified Regional SLR
Projection, provides an update to the amount of anticipated sea level rise in Southeast Florida
through 2120. These projections represent a consensus from a technical Work Group consisting of
members from the academic community and federal agencies, with support from local government
staff, and incorporates the most up-to-date,peer-reviewed literature, and climate modeling data.
Support for this item provides acceptance of the 2019 update to the Unified Regional SLR Projection
for Southeast Florida as the basis for sea level rise adaptation planning in Monroe County and in
coordination with our regional partners as shown in the SE FL Regional Climate Change Compact
Sea Level Rise Projections Graph 2019 (Exhibit 1). This action helps to ensure that all major
infrastructure projects and planning decisions in Monroe County and the Southeast Florida region
are informed and guided by a common, geographically-relevant sea level rise projection.
The Unified Regional SLR Projection consists of the three planning curves as the basis for a
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Southeast Florida sea level rise projection for the 2040 and 2070 planning horizons. These curves are
projected from the year 2000 to 2120 and include: National Oceanic and Atmospheric
Administration (NOAA) High curve, the NOAA Intermediate High curve, and the median of the
Intergovernmental Panel on Climate Change (IPCC) Assessment Report 5 (AR5) Representative
Concentration Pathway (RCP) 8.5 scenario from the IPCC, 2013 report.
Mean sea level rise (above the 2000 mean sea level in Key West) is projected to be the following:
• 10 to 17 inches by 2040
• 21 to 54 inches by 2070, and
• 40 to 136 inches by 2120.
Sea level measured at the Key West gauge has risen approximately 3.9 inches from 2000 to 2017.
Interannual and interdecadal variation in the sea level rate of rise is anticipated, as is a persistent
increase in sea level over the long term. Since 2013, the observed mean sea level has varied between
the IPCC Median and NOAA Intermediate-High curves.
Projected sea level rise, especially beyond 2070, has a significant range of variation as a result of
uncertainty in future greenhouse gas emissions reduction efforts and resulting geophysical effects. A
forth curve, the NOAA Extreme, is included for informational purposes, illustrating the possible
upper limit of sea level rise in response to potentially massive ice sheet collapse in the latter part of
the century. The IPCC Median or lower blue shaded portion of the projection can be applied to most
adaptable infrastructure projects to be replaced before 2070 or projects whose failure would result in
limited consequences to others. Projects in need of a greater factor of safety related to potential
inundation or with lower capacity to adapt mid-life should consider designing for the NOAA
Intermediate High Curve. For critical infrastructure projects with design lives in excess of 50 years
or low capacity to adapt mid-life, use of the NOAA High curve is recommended with planning
values of 54 inches in 2070 and 136 inches in 2120. Sea level will continue to rise even if global
mitigation efforts to reduce greenhouse gas emissions are successful at stabilizing or reducing
atmospheric Carbon Dioxide concentrations; however, emissions mitigation is essential to moderate
the severity of potential impacts in the future. A substantial increase in sea level rise within this
century is likely and may occur in rapid pulses rather than gradually.
The 2019 update presents several adjustments to the current Regional SLR Projection (2015), as
follows:
• The regional sea level projections provided by the National Oceanographic and Atmospheric
Administration (NOAA) replaced two of the three previously used curves. The selected
curves are regional projections rather than previously used global projections. The NOAA
Intermediate High regional projection was selected as the upper boundary for typical
infrastructure because of its IPCC determination to be very likely under the RCP 8.5
emissions pathway, which aligns with current global emissions trends. The NOAA
Intermediate High regional projection also approximates the previously used U.S. Army
Corps of Engineers (USACE) High curve. The NOAA High curve was updated with its
regional projection. The third curve, the IPCC Median, was reprojected for the region (Key
West)rather than global scale, using the NOAA (Sweet et al., 2017) methodology.
• The year 2000 has been selected as the initial year of the projection because of its use as the
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reference year for the latest regional sea level projections published by NOAA. NOAA has
determined a new mean sea level for 2000, the midpoint of the tidal epoch from 1991 to
2009.
• The NOAA Extreme curve is displayed on the Unified Regional Sea Level Rise Projection
for informational purposes but is not recommended for design.
The Unified Sea Level Rise Projection Southeast Florida Guidance Document describes the
recommended application of the projection as it relates to both high- and low-risk projects and short-
and long-term planning efforts along with the methodology and science applied to develop the
projection (Exhibit 2).
The recommended projection provides guidance for the Compact Counties and their partners to plan
for and address the anticipated impacts of sea level rise within and across the region. The near-term
planning horizons (through 2070) are critical to implementation of the Southeast Florida Regional
Climate Change Action Plan and Monroe County's GreenKeys Plan and to efforts to optimize the
remaining economic life of existing infrastructure while advancing adaptation strategies. As
scientists continue to improve our understanding of the factors and reinforcing feedback mechanisms
impacting sea level rise, the Southeast Florida community will need to adjust the projections
accordingly and adapt to the changing conditions. To ensure public safety and economic viability in
the long-run, strategic policy decisions will be needed to develop guidelines to direct future public
and private investments to areas less vulnerable to future sea level rise impacts while working to
reduce impacts in areas at risk.
PREVIOUS RELEVANT BOCC ACTION:
January 20, 2010: BOCC approved the Southeast Florida Regional Climate Compact by Resolution
022-2010.
July 20, 2011 the BOCC approved the use of"A Unified Sea Level Rise Projection for Southeast
Florida," for planning purposes.
December 9, 2015: Approval to accept the updated Unified Regional Sea Level Rise Projections
(2015) of the Southeast Florida Regional Climate Change Compact and direct staff to utilize the
updated projection as the basis for sea level rise adaptation planning activities.
CONTRACT/AGREEMENT CHANGES:
N/A
STAFF RECOMMENDATION: Approval
DOCUMENTATION:
Exhibit 1 SLR Projection Graph
Exhibit 2 - SE FL Climate Compact Sea Level Rise Projection Guidance Report 2020
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FINANCIAL IMPACT:
Effective Date: March 18, 2020 Expiration Date: N/A
Total Dollar Value of Contract: N/A
Total Cost to County: To be determined
Current Year Portion: N/A Budgeted: N/A
Source of Funds: N/A CPI: N/A
Indirect Costs: Cost to Adapt County Infrastructure to sea level rise based on these revised
projections
Estimated Ongoing Costs Not Included in above dollar amounts: TBD
Revenue Producing: No If yes, amount:
Grant: N/A
County Match: N/A
Insurance Required: No
Additional Details:
REVIEWED BY:
Rhonda Haag Completed 02/26/2020 12:08 PM
Pedro Mercado Completed 03/04/2020 9:29 AM
Budget and Finance Completed 03/04/2020 9:35 AM
Maria Slavik Completed 03/04/2020 9:38 AM
Kathy Peters Completed 03/04/2020 9:39 AM
Board of County Commissioners Completed 03/18/2020 9:00 AM
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