Emerging tools for emissions drawdown on land and sea

By Brad Warren, NFCC/Global Ocean Health, Revised December 1st, 2019

For decades, failure to reduce carbon pollution has been a central conundrum for humankind, producing obvious consequences across both marine and terrestrial systems. Unchecked carbon emissions are degrading marine foodwebs, disrupting fisheries production, threatening world seafood supplies, and propelling many other troubling changes.

Despite earnest and intelligent efforts, greenhouse gas emissions have increased by 55% since 1990 (Olivier & Peters 2018). The dominant component of this swelling emission stream is carbon dioxide (73% of the total), almost entirely from burning fossil fuels. In many developed nations, carbon emissions have continued to increase in the transportation sector even as other sectors of the economy have managed to flatten or reduce emissions. Over the last five years, monthly mean atmospheric concentration of CO₂ (recorded at Mauna Loa Observatory) has climbed from about 398 ppm to 410 ppm (NOAA 2018).

In response to this conundrum, some leaders in business, government and the scientific community developed new ways to reduce pollution that may be achievable without a major fight with fossil fuel interests ,which have successfully blocked most other pathways. A major class of intervention that is generating increased attention lately (and attracting some investment from oil companies) is carbon removal. The enabling tools are sometimes described as Negative Emissions Technologies (NETs). Drawing down CO₂ to help mitigate changes in climate and sometimes ocean chemistry, these approaches harness natural systems (both terrestrial and marine) and abiotic technologies (carbon capture and sequestration systems). 

These technologies have important implications for the future of marine resources and ocean use. Any plausible pathway to large-scale emissions removal requires a place to put the carbon, potentially on a scale of tens of billions of tons annually. The signs point to the ocean. The ocean and coastal zones are primary venues for many sequestration projects, in part due to the geochemistry of saline aquifers which facilitates reactions that bind carbon into carbonate minerals. As carbon dioxide removal grows into a major industry, we anticipate a need to learn quickly how to govern it, how to structure enterprises for optimal performance and public accountability, and how to refine the technologies to ensure that risks are well contained.

Negative Emissions Technologies

Options to accelerate capture and sequestration of CO₂ in natural and artificial systems have become an important theme in global climate policy discussions. They provide a supplemental strategy at a time when leaders and researchers anticipate that climate targets cannot be achieved through emission reduction alone. Indeed, negative emissions technologies (NETS) play a part in most emissions scenarios that could limit global warming to 2°C in the latest IPCC Assessment Report (2014) according to a review of NETS options and their limitations published in Nature (Smith et al 2016).

Authors of a 2018 US National Academies of Science, Engineering and Medicine study on NETs noted: “it would be extremely difficult to reduce net anthropogenic emissions enough to achieve declining atmospheric CO₂ without the use of NETs because of fossil and land-use sources that would be extremely disruptive or expensive to mitigate, such as some agricultural methane or CO₂ from air travel.” (National Academies 2018). The National Academies study authors observe that NETs offer the most powerful known mechanisms to reduce atmospheric concentration of GHGs: “Unlike other forms of mitigation, NETs provide the only means to achieve deep (i.e. > 100 ppm) emissions reductions, beyond the capacity of the natural sinks.”

Several approaches to CO₂ drawdown may deliver additional benefits that serve or complement conservation priorities:  earning revenue, creating jobs, conserving and restoring habitats, and locally remediating ocean acidification and other pollution that degrades habitat and water quality.

Natural systems offer low-cost drawdown. Compared to artificial methods, the National Academies study found that drawdown approaches using natural systems offer significant cost advantages, but vary widely in their potential to remove large quantities of CO₂ from circulation (see Table 8.1 from National Academies report, reproduced on page 11). The study evaluated coastal blue carbon, forest carbon, agricultural soil carbon, biofuel energy production with carbon capture and sequestration, direct air capture, and four variants of mineralization, an approach that captures carbon and binds it in mineral form. Narrowing this list, the report identifies four land-based NET approaches “that could be scaled up to capture and store substantial amounts of carbon.” It should be noted that other authors in the field see additional opportunities for removing emissions at larger scale in the ocean. Those will be addressed below. The four approaches identified by the National Academies authors are afforestation/reforestation, changes in forest management, uptake and storage by agricultural soils, and biomass energy with carbon capture and storage (BECCS).

The NAS authors observe: “These approaches have co-benefits, including:

• increased forest productivity (changes in forest management);
• improved agricultural productivity, soil nitrogen retention, and soil water holding capacity (enhanced uptake and storage by agricultural soils); and
• liquid fuel production and electricity generation (BECCS).”

Forest carbon. To date, forest carbon is the most fully developed form of NET. The National Academies study estimates the worldwide potential of this approach to be large: between 570 and 1125 GT of CO_2, removal, at costs of $15 to $50 per ton removed.  However, the study estimates that the total removal potential for forests in the US is modest, with a range of 0.15 to 38 GT.

Increasing carbon storage in agricultural soils is another large, low-cost option. Estimated costs per ton of CO₂ run $0-50 for climate-friendly agricultural practices that enhance soil sequestration (In some cases, soil-based carbon sequestration may carry no cost because farmers can profitably switch to soil-regenerating, carbon-burying practices)

One potentially important pathway for mineralization of CO₂ is called “accelerated weathering” because it involves speeding up the natural process by which alkaline rocks gradually weather into rock powder, mix into water and bind CO₂ over geologic time. The Academies authors estimate the cost per ton of CO₂ removed through such processes to be as low as <$10 for the least-cost options of this type.

Coastal blue carbon is characterized as a small but low-cost option. The National Academies study reports that blue carbon could remove an estimated 0.26 to 4 GT of CO₂ in the US and 8 to 65 GT worldwide, at a cost of $10/t.

How far can it go? The volume of CO₂ that can be removed by NET approaches is still subject to debate. However, the NAS report also notes that many constraints will narrow the scope for NET deployment. Focusing on opportunities that could be achieved safely and at costs below $100/t, the National Academies study reckons that the four land-based technologies identified as ready to scale up (see detail above) potentially could remove up to 1 GT of CO₂/yr in the US, and up to 10 GT/yr globally.

The authors note that practical constraints are likely to prevent the four land-based approaches from attaining their maximum potential. Further, they concur with other authors (Rau et al 2018) in concluding that even those ambitious levels for land-based CO₂ removal will fall short. They observe that “attaining these levels (e.g. up to 1 GT/yr removal in the US, and 10 GT/yr globally) would require unprecedented rates of adoption of agricultural soil conservation practices, forestry management practices, and waste biomass capture.”

At the same time, the world will need more, larger tools to draw down CO₂ (even presuming that efforts to cut emissions are successful), if we aim to stabilize the climate at <2°C of warming. The National Academies authors estimate that “NETs will likely need to ramp up rapidly before mid-century to remove up to 20 GT CO₂/yr globally by century’s end.”

Other investigators support views offered by the National Academies authors on several key points:

1. Deployment of technologies to draw down CO₂ will be limited by economic, geographic and environmental constraints.
2. Bigger draw-down tools are needed (and may be available, see below)
3. Relying on drawdown without deep emission reductions would constitute a highly risky strategy, given the major uncertainties and reliability questions about how far negative-emissions approaches can practically be deployed.

In a study evaluating the limits to drawdown technologies, Smith et al (2016) also offer the reservation that some NETs, especially the important category of bio-energy combined with carbon capture and sequestration (BECCS) will face competition for land, water and available nutrients.

Smith et al also warn that reliance on NETs “to allow continued use of fossil fuels in the present is extremely risky” due to uncertainties about the biophysical and economic limits that could prevent these tools from scaling up enough to stabilize the climate.  Smith and co-authors observe that “there is no NET, or combination of NETs, available now that could be implemented to meet the <2°C target without significant impact on either land, energy, water, nutrient, albedo or cost.” Smith and co-authors conclude: “’Plan A’ must be to reduce GHG emissions aggressively now.”

The IPCC emphatically concurs with this warning. Its draft 2018 Special Report (IPCC 2018) focuses on ways to avoid crossing the tighter threshold for warming that has emerged from recent research: a limit of 1.5°C. That ambitious new target demands deeper cuts in emissions and could push nations to lean harder on carbon dioxideremoval (CDR). But the IPCC warns against over-dependence on such a novel, untested approach: “CDR deployed at scale is unproven and reliance on such technology is a major risk in the ability to limit warning to 1.5°C.” The panel affirms the view that land-based CDR via forest or BECCS will face “trade-offs with other sustainability objectives… predominantly through increased land, energy, water and investment demand.”

For better or worse, the world now is committed to CO₂ drawdown, whatever its risks. There is no way to avoid long-lasting commitment to warming above 1.5°C without it. As the IPCC 2018 draft Special Report authors note: “All analyzed 1.5°C –consistent pathways use CDR to some extent to neutralize emissions from sources for which no mitigation measures have been identified and, in most cases, also to achieve net-negative emissions that allow temperature to return to 1.5°C following an overshoot (high confidence). The longer the delay in reducing CO₂ emissions toward zero, the larger the likelihood of exceeding 1.5°C, and the heavier the implied reliance on net-negative emissions after mid-century to return warming to 1.5°C.”

Going to sea. The world’s increasing, if inadvertent, commitment to large-scale CDR heightens the need for research on the biggest potential venue for CO₂ removal: the ocean. Greg Rau, a marine chemist and researcher at UC Santa Cruz, is one of the pioneers of methods for accelerating CO₂ removal in the ocean. Rau has advocated an increase in scientific research to better understand the potential and limitations of the ocean’s capacity to clean up humankind’s biggest pollution problem. Rau notes that the ocean covers 70% of the Earth, provides more than 90% of its existing surface storage of carbon, and performs 50% of natural CO₂ removal today (Rau pers. comm. 2, 2018) by absorbing the gas from the air and capturing it in biological and geological forms. It should noted that experts on CDR are still debating the relative importance of land-based and marine carbon transfer. Authors of the 2018 NAS report took a more conservative view of ocean carbon sinks,  which they estimated to be smaller than terrestrial ones. The NAS authors focused mainly on terrestrial approaches, and considered marine CDR potential only from “coastal blue carbon,” the narrow strip of photosynthesizing marine grasses and algae that occupies estuaries and shores.

Rau and co-authors (Rau et al 2018) found that one suite of marine-based technologies could yield 50 times more CO₂ reduction and energy than BECCS, at lower cost. Their study examines the magnitude and feasibility of technologies to amplify the CO₂ reduction power of some NETs by converting electricity (from bio-fuels, wind and solar sources) to negative-emissions hydrogen. This approach uses electrolysis to extract hydrogen from water.

Referred to as “negative-emissions hydrogen” (NE H₂) this approach may hold particular interest for fishery-dependent coastal communities, states, and enterprises, for several reasons:

1. The electrolysis process used to produce hydrogen can also (with the addition of calcium carbonate from rock or shell) drive CO_2, into carbonate mineral form (e.g. bicarbonate) in seawater. Proponents suggest this could remediate some CO₂-induced acidification in local waters (a claim disputed by some experts) while also removing CO₂ from the atmosphere (Removing CO₂ and Remediating acidification: Rau et al 2018; Extreme local conditions: Murray et al 2015, Pacella 2017.).
2. The process can convert variable wind and solar power to hydrogen, a stable storage medium for energy, to be used when needed.
3. The hydrogen itself can be stored and transported in the existing infrastructure of natural gas pipelines, a 2.2 million mile network that comprises the largest energy storage system in the U.S. This may provide a de-carbonization pathway for natural gas utilities, helping to enfranchise them in creating a renewable energy system which might otherwise be viewed as a threat to their market share.

Rau notes that this electrochemical approach could be piloted at small scale in bays to assess potential use of carbonate mineral byproducts to remediate acidification.  (Rau pers. comm. 2018). If successful, this could add a new tool to the kit for addressing the increasingly severe acidification impacts noted in 2017 by Washington’s Marine Resource Advisory Council, which carries forward the work of the state’s original Blue Ribbon Panel on Ocean Acidification.  The Advisory Council noted (Washington MRAC 2017) that acidification is now affecting both wild and cultured bivalves in the region and causing visible damage to planktonic species (notably pteropods) that form an important part of salmon diets.

The Renewable Hydrogen Alliance, based in Portland Oregon, is a new forum established by leaders in renewable energy and utilities to pursue a vision that could complement the potential of some NETs approaches both on land and at sea. They envision using electrolysis powered by ultra-low-cost renewable power at times of surplus solar and wind production. Converting this electricity to hydrogen ensures the cheap power can be used (not wasted) when needed. This makes “a more efficient use of the energy created and increases the value of renewables by creating flexible demand for power when it can’t otherwise be efficiently put to good use.” This renewably produced hydrogen, in time, could gradually replace hydrogen derived from natural gas, with its significant carbon footprint. “Transitioning to creating hydrogen from water and renewable electricity is a vital part of realizing a low-carbon future,” the group states.

Seaweed-based solutions. Another approach that may be consistent with conservation priorities is growing marine macroalgae to reduce CO₂concentration in seawater, remediating local acidification and potentially contributing to global emissions reduction and adaptation approaches.  A major review of seaweed potential in climate solutions (Duarte et al 2017) identified multiple benefits to this approach. Seaweed farms export carbon as detritus to marine sediments, where it is thought that currents can carry it to the deep sea for long-term sequestration. Production of biofuel from seaweed crops can yield CO₂ mitigation of ~1,500 tons CO₂ per km^-2 (i.e. 1/4 of square kilometer). Duarte and co-authors observe: “Seaweed aquaculture can also help reduce the emissions from agriculture, by improving soil quality substituting synthetic fertilizer and when included in cattle feed, lowering methane emissions from cattle.” This form of aquaculture also enhances coastal climate resilience by “damping wave energy and protecting shorelines, and by elevating pH and supplying oxygen to the waters, thereby locally reducing the effects of ocean acidification and de-oxygenation.”

Duarte and co-authors estimate the upper limit for CO₂ capture by cultured seaweed worldwide at about 2.48 million tons annually, assuming that all of the 27.3 million tons fresh weight produced in 2014 could be dedicated to carbon capture. They note, however, that “this upper limit constitutes only about 0.4% of the global wild seaweed CO₂ capture” over an area of 3.5 million km². Duarte et al conclude that seaweed aquaculture, covering only about 1,600 km² today, “does not yet have a scale that would support a global role in climate change mitigation,” but its intensity of 1,500 tons CO₂ per km^-2 could be a significant tool for local climate strategies. Acknowledging that marine nutrient supplies, light availability and other factors may constrain expansion of seaweed crops, Duarte et al still find that “the scope for expansion of seaweed aquaculture with available structures and constraints is substantial.” They note that Norway has identified seaweed aquaculture as a promising field for expansion, tripling the area under cultivation along its coast from 2014 to 2016.

While Duarte et al find that seaweed farming “cannot be the option of choice if the sole intent is to mitigate climate change,” they note that it provides a lower-cost option than offshore wind power development. A 1-hectare seaweed farm can be started with an initial investment of $15,000 in Mexico, “whereas a state-of-the-art offshore wind turbine, including installation, is about $1.5 million per turbine, and involves order-of-magnitude larger maintenance costs.” Duarte and co-authors suggest that this cost advantage, coupled with co-benefits from food, biomass, animal feed, and other functions, could make seaweed farming a suitable option for developing countries that cannot afford more expensive solutions.

From Waste to Resource: Environmental engineering technologies are increasingly capable of capturing carbon and other materials from wastewater and converting it to beneficial uses. This applies to both municipal and industrial wastewater, with potential to deliver multiple co-benefits. In addition to their massive discharges of nutrient wastes, wastewater treatment plants generate about 1.6% of the world’s greenhouse gas emissions, and consume nearly 3% of global electricity. Indeed, “for many cities and towns, wastewater treatment plants are the largest energy consumers,” note Lulu et al (2018) in a new paper published in Nature Sustainability that proposes to capture and reuse carbon emissions and other wastes from these processes.

A combination of electrochemical, microbial, and phototrophic processes can reduce emissions and water pollution, provide materials for habitat restoration and soil-building farming practices, Lulu and co-authors report. Their paper offers a broad range of technical approaches, many of which show potential to serve tribal priorities for environmental cleanup and restoration as well as emission reduction. Lulu and co-authors propose that wastewater treatment can be integrated with carbon capture and utilization (CCU) and other technologies to perform a more useful function as “water resource recovery facilities” (WRRFs). These could “recover energy, nutrients, water and other valuable carbon products with economic, environmental and social benefits.”

In one example, Lulu and coauthors describe how electrolytic carbon capture can be applied, using wastewater as the electrolyte in a microbially-assisted process. This approach can extract 80-93% of CO₂and 50-100% of organics from wastewater. It also generate a net energy gain—potentially turning wastewater treatment plants into power plants.

The authors note that use of constructed wetlands can accelerate capture of CO₂, while other methods have been demonstrated to simultaneously capture and utilize CO₂ from wastewater while removing nutrient wastes that normally are discharged to downstream waters.

One interesting approach suggested by these authors is the conversion of wastewater sludge to biochar. Lulu and co-authors note that this carbon-rich material can substitute for woody biomass as a feedstock for production of biochar for use in soil enrichment and remediation of pollutants and environmental hazards. They write: “Compared with current disposal practices of landfilling and direct land application, carbonizing the sludge into biochar may provide higher environmental and economic benefits. Sludge biochar eliminates pathogens, improves soil structure and increases agricultural output. Moreover, studies have shown that such biochar can adsorb pesticides, reduce heavy metal leaching and increase soil fertility.” They cite research indicating sharp increases in yield for cherry tomatoes grown in soil enriched with sludge biochar.

Incorporation of biochar into soils also sequesters carbon. Citing previously published research on this approach. Lulu and co-authors calculate as follows: “For a wastewater treatment plant generating 100 dry tons of sewage sludge per day, an estimated 65 tons of biochar can be generated assuming a median yield of 65% and ~21 ktCO₂e may be captured per year based on a GHG emission of 0.9 kg CO₂e per kg biochar.”

By converting industrial wastewater into a resource instead of a waste product, Lulu and co-authors note that substantial amounts of GHG reduction and other environmental benefits can be realized. They write that “nearly 3.3 billion cubic meters of wastewater are generated from the oil and gas industry ever year in the US alone. The use of such waste streams for in situ CCU of GHGs from oil and gas could have significant benefits for the industry, not the least of which would stem from environmental and economic benefits of water reuse relative to deep well injections.”

Key Take-home Points

1. Prepare for changing ocean use. It appears likely that coastal and ocean spaces will see carbon removal emerge as a major new activity in the next few decades. Marine resource managers, users, and coastal communities (including tribes) have much a stake in learning about this nascent field and building appropriate systems to govern it. A carbon removal industry handling 20 billion tons of CO₂ annually, as projected by IPCC in its SR15 report (IPCC 2018) would be approximately 200 times larger than the world’s total fishing industry,  if measured solely by volume of material moved. If average carbon prices rise to $50/ton (the price now established by a US tax credit for sequestration in wells), a global carbon management industry that removes 20 billion tons per year would earn revenues of $1 trillion annually.
2. Structure of enterprises and policy landscape.  From a public-interest point of view, those interested in minimizing the risks and optimizing the benefits of this new CDR industry may find useful parallels in the historic development of electricity utilities during the late 19th and early 20th centuries. The the widespread and critical need for electric power led to creation of public utilities that were designed to be accountable to the public they served, while still interacting seamlessly with capital markets. The utility model may be a useful one to consider as coastal societies contemplate how to govern a very large new enterprise serving critical societal needs for carbon removal and clean energy, operating at the intersection of existing energy utilities and capital markets, and affecting multiple interests on shore and at sea. 
3. Siting: Ocean or land?.  Will most CDR activity occur on the ocean and coasts, or on land? This is not a settled matter, but the ocean will likely have a major role.
4. Implications for fisheries, marine resources, & coastal communities. A large CDR industry can be expected to present multiple challenges and opportunities for living marine resources, ocean users, and communities that depend on the ocean. Such an industry will: provide carbon management services that are necessary to protect living marine resources and coastal communities from effects of unchecked carbon emissions; present hazards for living marine resources that will need to be studied and managed carefully, such as large-scale modification of marine carbonate chemistry parameters; create demand for limestone in large volumes, potentially causing significant environmental and social challenges; generate hydrogen that can facilitate the growth of  renewable energy and the transition of gas-dependent utilities and their customers into a lower-carbon economy; create employment and opportunity for businesses; and compete for coastal and marine space with existing users.

Additional figures and tables below:

1. Carbon removal methods considered by the NAS 2018 report.
2. Emission pathways showing reliance on carbon removal, from IPCC SR15 2018, Summary for Policymakers.
3. Two of four model pathways considered by IPCC, from IPCC SR 15 2018.
4. Role of negative emissions technologies in reaching net zero emissions, from NAS 2018.
5. Summary of major negative emission technologies, from NAS 2018.

F

REFERENCES

Duarte et al 2017. Can Seaweed Farming Playa Role in Climate Change Mitigation and Adaptation? Frontiers in Marine Science, 12 April 2017, https://www.frontiersin.org/articles/10.3389/fmars.2017.00100/full

EIA 2016. Primary energy, electricity, and total energy expenditure estimates, 2016.” Energy Information Administration.  https://www.eia.gov/state/seds/seds-data-complete.php?sid=WA#PricesExpenditures

Hibbard et al 2018. The Economic Impacts of the Regional Greenhouse Gas Initiative on Nine Northeast and Mid-Atlantic States.  Analysis Group, April 17, 2018. https://www.analysisgroup.com/globalassets/uploadedfiles/content/insights/publishing/analysis_group_rggi_report_april_2018.pdf

IPCC 2014. Climate Change 2014: Mitigation of Climate Change. Working Group III Contribution to the Fifth Assessment Report, Intergovernmental Panel on Climate Change, 2014. Edenhofer et al, eds. https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_full.pdfh

IPCC 2018.  Special Report: Global Warming of 1.5^o C, Technical Summary, Intergovernmental Panel on Climate Change, 2018. https://www.ipcc.ch/sr15/about/

Lulu et al 2018. Wastewater treatment for carbon capture and utilization. Nature Sustainability, Vol 1, December 2018,  750-758. https://www.nature.com/articles/s41893-018-0187-9.epdf?author_access_token=jE1cDdPhW80MEB4P0Yp-7dRgN0jAjWel9jnR3ZoTv0MI9dfBew-n2U3AxOPRibsgS5pyl0Ei5ZESPB73SpLIqmsVp9ndk2gprkHwwGb2KuQAwQBcSxh0fGGwnWFGBRCLST9tLkBuUL3W-MS-m7kvpQ%3D%3Dh

Murray et al 2015. An inland sea high nitrate-low chlorophyll (HNCL) region with naturally high pCO₂, Limnology and Oceanography, 60, 2015, 957-966. https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.10062

National Academies 2018. Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. National Academies Press. https://doi.org/10.17226/25259, also: https://www.nap.edu/catalog/25259/negative-emissions-technologies-and-reliable-sequestration-a-research-agenda

NOAA 2018. Recent Monthly Mean Average Mona Loa CO₂  Earth System Research Laboratory,  Global Monitoring Division, National Oceanic & Atmospheric Administration. https://www.esrl.noaa.gov/gmd/ccgg/trends/index.html

Olivier & Peters, 2018. Trends in Global CO₂  and Total Greenhouse Gas Emissions: 2018 Report, PBL Netherlands Environmental Assessment Agency, December 2018. https://www.pbl.nl/sites/default/files/cms/publicaties/pbl-2018-trends-in-global-co2-and-total-greenhouse-gas-emissons-2018-report_3125.pdf

Pacella et al 2017. Seagrass habitat metabolism increases short-term extremes and long-term offset of CO₂ under future ocean acidification. Proceedings of the National Academy of Sciences (PNAS), published ahead of print April 2, 2018.  https://doi.org/10.1073/pnas.1703445115

Rau et al 2018.  The global potential for converting renewable electricity to negative- CO₂-emissions hydrogen. Nature Climate Change, https://doi.org/10.1038/s41558-018-0203-0

Rau pers. comm. 1, 2018. Email to Brad Warren, Dec 4, 2018.

Rau pers. comm. 2, 2018. Email to Google Group discussion on CDR, Dec 24, 2018.

Smith et al 2016. Biophysical and economic limits to negative CO₂ emissions. Nature Climate Change 6, 42-50 (2016), https://www.nature.com/articles/nclimate2870 or https://core.ac.uk/download/pdf/77052341.pdf.

Snohomish County 1, undated. Grow Here, web page: https://snohomishcountywa.gov/DocumentCenter/View/40707/Agriculture?bidId=

Snohomish County 2, undated. Forest Resource Lands Planning, Snohomish County Planning & Development Services, web page: https://snohomishcountywa.gov/1538/Forest-Resource-Lands-Planning

Washington MRAC 2017. Addendum to Ocean Acidification: From Knowledge to Action. Washington State’s Strategic Response. Washington Marine Resources Advisory Council. 2017, December 2017. http://oainwa.org/assets/docs/2017_Addendum_BRP_Report_fullreport.pdf