Carbon Sequestration as part of Everglades Restoration: An NAS Blue Carbon Discussion

Transcription

1 Carbon Sequestration as part of Everglades Restoration: An NAS Blue Carbon Discussion Fred H. Sklar Director Everglades System Assessment Section South Florida Water Management District July 19, 2017

2 System STAs Tree Islands, Ridges & Sloughs Mangroves Estuary (Seagrass) SOUTH FLORIDA WATER M A N A G E M E N T DISTRICT References ECOLOGY OF CO 2 SEQUESTRATION as an example. PhD Dissertation, University of Florida. IN THE EVERGLADES 1) Bhomia, R.K Long-term accretion of phosphorus in wetlands: The Everglades STAs 2) URS Corporation, Stormwater Treatment Area Carbon Sequestration and Offset Analysis. Technical Report for the SFWMD. 1) Newman et al Drivers of landscape evolution: multiple regimes and their influence on carbon sequestration in a sub-tropical peatland. Ecol. Monographs. 2) Aich et al Estimating soil subsidence and carbon loss in the Everglades Agricultural Area, Florida... Ag Eco Environ 3) Hohner and Dreschel, Everglades peats: Using historical and recent data to estimate predrainage and current volumes, masses and carbon contents. Mires and Peats, 16: ) Jerath et al The role of economic, policy and ecological factors in estimating value of carbon stocks in Everglades mangrove forest, south Florida, USA. Environmental Science and Policy. 2) Sklar and Dreschel, eds Chapter 6 Everglades, South Florida Environmental Report, SFWMD Technical Report. 1) Fourqurean et al 2012, Seagrass ecosystems as a globally significant carbon stock. Nature Geoscience, DOI: /NGEO1477 General 1) Richardson et al Assessing the value of the CEPP in Everglades restoration: an ecosystem service approach. Ecological Economics 2) Mather Economics Measuring the Economic Benefits of Everglades Restoration, 35p. 3) CE Lovelock et al., Assessing the risk of carbon dioxide emissions from blue carbon ecosystems. Front Ecol Environ 2017;15(5): ) Florida Department of Agriculture and Consumer Services Florida Agriculture by the Numbers. 176p.

3 BLUE CARBON EMISSIONS AND SEQUESTRATION POTENTIAL Restoration reinstates the sedimentary biogeochemical conditions and the soil stability in disturbed sites It also enhances C org storage by increasing the living biomass and its capacity to sequester CO 2 and by trapping organic material that is delivered in tidal flows. CE Lovelock et al., Assessing the risk of carbon dioxide emissions from blue carbon ecosystems. Front Ecol Environ 2017;15(5):

4 Hohner and Dreschel, Everglades Peats. Mires and Peat. 16:1-15. SOUTH FLORIDA WATER M A N A G E M E N T DISTRICT Predrainage Everglades had a peat depth of 2 m, a peat volume of 20 billion m 3, and a carbon content of about 900 million metric tons. Current Everglades has a peat depth of 0.75 m, a peat volume of 5 billion m 3, and a carbon content of about 200 million metric tons.

5 100 YEARS OF SOIL OXIDATION Peat Subsidence (ft) Peat Subsidence (ft) Dreschel et al. 2015

6 Peat Collapse is a function of storms, soil oxidation, hydrologic stress, and salt inundation. Peat Collapse

7 SOUTH S O U T H FLORIDA F L O R I D A WATER W A T E R M A N A G EE M EE NN T T D DISTRICT I S T R I C T Planning Everglades Restoration in what has become an Urban-Agricultural-Wetland Watershed Citrus and Livestock 50,000 ha Everglades Agricultural Area (EAA) Sugarcane (65%) Sod (20%) Vegetables (rice, beans, lettuce, corn 15%) 280,000 ha Urban Centers (West Palm Beach, Ft Lauderdale, Miami) 5,800,000 people South Florida Agriculture Fruit (citrus, mangoes, strawberry - 20%) Winter Vegetables (tomatoes, lettuce, peppers, squash - 60%) 100,000 ha

8 Compartmentalization

9 Stormwater Treatment Areas (STAs) were mandated in the Everglades Forever Act

10 Central Everglades Planning Process (CEPP)

11 C-111/SOUTH DADE S-332D High Head Cell Weir

12 S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T The Perfect World: The Comprehensive Everglades Restoration Plan( CERP)

13 REGIONAL (DRAFT) CARBON SEQUESTRATION In a STA (Everglades Forever Act) World REGION Size (m2) Affected Area (m 2 ) Restoration Soil Accretion Rate (mm/yr) Accretion gc/m 2 /yr (using 0.1 g/cm3 and 0.45 for %C) Accretion (tonnes C/ha/yr) Regional Carbon Removal Efficiency (Million tonnes CO 2 /yr) EAA 2,560,010, STA 230,000, ,000, , WCA1 559,267, ,633, WCA2A 417,710, ,282, WCA2B 114,390, WCA3AN 721,524, ,381, WCA3AS 1,286,544, ,654, WCA3B 398,294, Ochopee Marl Marsh 381,371, Shark River Slough (SRS) 767,438, SRS Mangroves 1,083,352, Eastern Marls & Taylor Slough 795,225, Taylor Slough Mangroves 361,117, Florida Bay Seagrass 5,500,000, TOTAL TOTAL Average Average TOTAL TOTAL 15,176,250,098 1,131,952, ,132 km2 *Except Bulk Density of 0.33 Mg/m3 for the EAA and STA; 0.13 for mangroves.

14 REGIONAL (DRAFT) CARBON SEQUESTRATION In a C 111/South Dade World REGION Size (m2) Affected Area (m 2 ) Restoration Soil Accretion Rate (mm/yr) Accretion gc/m 2 /yr (using 0.1 g/cm3 and 0.45 for %C) Accretion (tonnes C/ha/yr) Regional Carbon Removal Efficiency (Million tonnes CO 2 /yr) EAA 2,560,010, STA 230,000, WCA1 559,267, WCA2A 417,710, WCA2B 114,390, WCA3AN 721,524, WCA3AS 1,286,544, WCA3B 398,294, Ochopee Marl Marsh 381,371, Shark River Slough (SRS) 767,438, SRS Mangroves 1,083,352, Eastern Marls & Taylor Slough 795,225, ,225, Taylor Slough Mangroves 361,117, ,558, Florida Bay Seagrass 5,500,000,000 2,750,000, TOTAL TOTAL Average Average TOTAL TOTAL 15,176,250,098 3,725,784, ,726 km2 *Except Bulk Density of 0.33 Mg/m3 for the EAA and STA; 0.13 for mangroves.

15 In a CEPP World SOUTH FLORIDA WATER M A N A G E M E N T DISTRICT REGIONAL (DRAFT) CARBON SEQUESTRATION REGION Size (m2) Affected Area (m 2 ) Restoration Soil Accretion Rate (mm/yr) Accretion gc/m 2 /yr (using 0.1 g/cm3 and 0.45 for %C) Accretion (tonnes C/ha/yr) Regional Carbon Removal Efficiency (Million tonnes CO 2 /yr) EAA 2,560,010, STA 300,000,000 70,000, , WCA1 559,267, ,633, WCA2A 417,710, ,427, WCA2B 114,390, WCA3AN 721,524, ,143, WCA3AS 1,286,544, ,465, WCA3B 398,294, ,721, Ochopee Marl Marsh 381,371, ,028, Shark River Slough (SRS) 767,438, ,438, SRS Mangroves 1,083,352, ,676, Eastern Marls & Taylor Slough 795,225, ,225, Taylor Slough Mangroves 361,117, ,558, Florida Bay Seagrass 5,500,000,000 2,750,000, TOTAL TOTAL Average Average TOTAL TOTAL 15,246,250,098 6,973,319, ,973 km2 *Except Bulk Density of 0.33 Mg/m3 for the EAA and STA; 0.13 for mangroves.

16 REGIONAL (DRAFT) CARBON SEQUESTRATION In a "Perfect" World Accretion gc/m 2 /yr (using 0.1 g/cm3 and 0.45 for %C) Regional Carbon Removal Efficiency (Million tonnes CO 2 /yr) REGION Size (m2) Restoration Soil Accretion Affected Area (m 2 ) Rate (mm/yr) Accretion (tonnes C/ha/yr) EAA 2,560,010,583 2,560,010, STA 300,000, ,000, , WCA1 559,267, ,267, WCA2A 417,710, ,710, WCA2B 114,390, ,390, WCA3AN 721,524, ,524, WCA3AS 1,286,544,854 1,286,544, WCA3B 398,294, ,294, Ochopee Marl Marsh 381,371, ,371, Shark River Slough (SRS) 767,438, ,438, SRS Mangroves 1,083,352, ,514, Eastern Marls & Taylor Slough 994,032, ,032, Taylor Slough Mangroves 361,117, ,117, Florida Bay Seagrass** 5,500,000,000 4,125,000, TOTAL TOTAL Average Average TOTAL TOTAL 15,445,056,557 13,799,218, ,799 km2 *Except Bulk Density of 0.33 Mg/m3 for the EAA and STA; 0.13 for mangroves.

17 ESTIMATED COSTS OF RESTORATION (DRAFT) Cost Elements STA s (Florida Forever Act) C-111 South Dade Project (Florida Bay and Mangroves ) CEPP Effected Zone (ha) 113, , ,300 Real Estate $293 M $150 M $36 M Pump Stations $34 M $133 M Earthworks, Control $728 M $60 M $1,110 M Structures & Canals Other (Mgmt., Design -- $60 M $480 M etc.) TOTAL $1,000 M $304 M $1,800 M O&M/year $29 M? $4 M Electric\Diesel/year $1M\$3.9M??

18 COST OF CARBON SEQUESTRATION IN THE SOIL (DRAFT) Project Estimate of Size of Carbon Affected Zone Removal (km 2 ) (Million tonnes CO 2 /yr) Estimated Economic cost of Restoration (no O&M) Annual Cost of CO2 Removal Discounted over 50 yrs ($/Million Tonnes) Efficiency (kg CO 2 removed/m2 per year) STA 1, $1,000,000,000 $13,967, C-111 3, $304,000,000 $7,062, CEPP 6, $1,800,000,000 $10,136, TOTAL 11, $3,104,000,000 $31,167, Perfect World (CERP+EAA) 13, $15,000,000,000 $34,120,

19 ECONOMIC BENEFITS -- ECOSYSTEM SERVICES VALUATION (DRAFT) OF EVERGLADES RESTORATION AFTER IMPLEMENTATION Service Groundwater Purification & Aquifer Recharge Real Estate (owner-occupied residential in 16 counties) CERP Mather Economics CEPP Richardson et al Valuation $263,000,000/yr $8,845,300/yr avoided cost of GW desalination 1 ; water supply LEC 2 $137,724,694/yr Not Estimated 10% water quality improvement (~7% of total); based on 50yr value Park Visitation $26,231,760/yr $6,429/yr travel-cost method, 2% increase over historic 1 ;closure days 2 Open Space $16,614,000/yr Not Estimated WTP per acre; based on 50yr value 1 Fishing -commercial $23,271,221/yr $17,580/yr fraction of state total 1 ;pink shrimp & gray snapper, Fl Bay 2 Fishing -recreational $90,464,861/yr $901,080/yr fraction of state total 1 ; seatrout, snapper, grouper, Fl Bay 2 Wildlife Hunting & Viewing $1,605,000,000/yr Not Estimated baseline estimate of hunting & wildlife recreation (fraction of state) 1 Climate Regulation Not Estimated Not Included Storm Protection & Coastal Stabilization Not Estimated TOTAL $2.162B $9.8M Not Estimated

20 COST OF CARBON SEQUESTRATION IN THE SOIL (DRAFT) Project Size of Affected Zone (km 2 ) Total Estimate of Carbon Removal (Million tonnes CO 2 /yr) Total Estimated Economic cost of Restoration (no O&M) Total Estimated Economic Benefits of Restoration (w/o climate regulation) Benefit-Cost Ratio STA 1, $1,000,000,000 C-111 3, $304,000,000 CEPP 6, $1,800,000,000 $488,867, TOTAL 11, $3,104,000,000 $37,279,522, Perfect World (CERP+EAA) 13, $15,000,000,000 $37,279,522, Richardson et al 1; Modified from Mather Economics 2

21 COST OF CARBON SEQUESTRATION IN THE SOIL (DRAFT) Project Total Estimate of Carbon Removal (Million metric tonnes CO 2 /50yr) Total Estimated Economic cost of Restoration (with O&M) Total CO 2 per $1 (kg CO 2 /$) Total Estimated Economic Benefits of Restoration (w/o climate regulation) Benefit-Cost Ratio (Total Benefit:Total Cost + O+M) STA 71.6 $2,450,000, C $440,000, CEPP $2,000,000, $488,867, TOTAL $4,854,000, $37,279,522, Perfect World (CERP+EAA) $16,750,000, $37,279,522, Richardson et al 1; Modified from Mather Economics 2

22 Uncertainties associated with blue carbon restoration in the Everglades: 1. How does saltwater intrusion accelerate soil decomposition? 2. How does increasing water tables associated with restoration alter the balance of methane and carbon dioxide fluxes? In Conclusion Peat Loss

23 In the face of accelerated sea level rise and increasing ET associated with climate change, there is an urgent need to maximize the carbon sequestration capacity of wetland and coastal systems. In Conclusion Peat Loss

24 Restoration of historic flows to the Everglades has great blue carbon potential by mitigating for seagrass dieoff, peat collapse, loss of ridge & slough habitat, subsidence and agricultural practices. In Conclusion Peat Loss

25 ACKNOWLEDGEMENTS Tiffany Troxler, FIU Tom Dreschel, SFWMD Carlos Coronado, SFWMD Amanda McDonald, SFWMD Ben Wilson, FIU Colin Saunders, SFWMD

26 S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Sediment Elevation Tables (SETs) Measure Elevation Change Surface: Sediment Deposition Sediment Erosion Subsurface: Root Growth Decomposition Porewater Storage Compaction

27 S O U T H F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Feldspar Marker Horizons Measure Sediment Deposition Sediment Deposition Subsurface: Root Growth Decomposition Porewater Storage Compaction

28 Elevation/Accretion (cm) Highway Creek: Basin (1.2 mm/yr) y = 0.121x y = x Accretion Time Elevation TF-13 TS-13 Linear (TF-13) Linear (TS-13) SET Data Low flow, Low nutrients, Always inundated Red = Accretion Brown = Elevation

29 Elevation/Accretion (cm) S O U T H 9.0 F L O R I D A W A T E R M A N A G E M E N T D I S T R I C T Argyle Henry: Mangrove (4.4 mm/yr) Elevation y = x Accretion y = x SET Data High flow, Moderate nutrients, Seasonal inundation with Freshwater Time TF-10 TS-10 Linear (TF-10) Linear (TS-10) Red = Accretion Brown = Elevation