skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Harvesting, storing, and converting carbon from the ocean to create a new carbon economy: Challenges and opportunities
Ever-increasing anthropogenic CO 2 emissions have required us to develop carbon capture, utilization, and storage (CCUS) technologies, and in order to address climate change, these options should be at scale. In addition to engineered systems of CO 2 capture from power plants and chemical processes, there are emerging approaches that include the Earth (i.e., air, Earth, and ocean) within its system boundary. Since oceans constitute the largest natural sink of CO 2 , technologies that can enhance carbon storage in the ocean are highly desired. Here, we discuss alkalinity enhancement and biologically inspired CO 2 hydration reactions that can shift the equilibrium of ocean water to pump more carbon into this natural sink. Further, we highlight recent work that can harvest and convert CO 2 captured by the ocean into chemicals, fuels, and materials using renewable energy such as off-shore wind. Through these emerging and innovative technologies, organic and inorganic carbon from ocean-based solutions can replace fossil-derived carbon and create a new carbon economy. It is critical to develop these ocean-based CCUS technologies without unintended environmental or ecological consequences, which will create a new engineered carbon cycle that is in harmony with the Earth’s system.  more » « less
Award ID(s):
1927336
PAR ID:
10400258
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Frontiers in Energy Research
Volume:
10
ISSN:
2296-598X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; (, Global Biogeochemical Cycles)
    Abstract Two centuries of anthropogenic CO2emissions have increased the CO2concentration of the atmosphere and the dissolved inorganic carbon (DIC) concentration of the ocean compared to preindustrial times. These anthropogenic carbon perturbations are often equated to the amount of anthropogenically emitted carbon in the atmosphere or ocean, which ignores the possibility of a shift of natural carbon between the oceanic and atmospheric carbon reservoirs. Here we use a data‐assimilated ocean circulation model and numerical tracers akin to ideal isotopes to label carbon when it is emitted by anthropogenic sources. We find that emitted carbon accounts for only about 45% of the atmospheric CO2increase since preindustrial times, the remaining 55% being natural CO2that outgassed from the ocean in response to anthropogenically emitted carbon invading the ocean. This outgassing is driven by the order‐10 seawater carbonate buffer factor which causes increased leakage of natural CO2as DIC concentrations increase. By 2020, the ocean had outgassed ∼159 Pg of natural carbon, which is counteracted by the ocean absorbing ∼347 Pg of emitted carbon, about 1.8 times more than the net increase in oceanic carbon storage of ∼188 PgC. These results do not challenge existing estimates of anthropogenically driven changes in atmospheric or oceanic carbon inventories, but they shed new light on the composition of these changes and the fate of anthropogenically emitted carbon in the Earth system. 
    more » « less
  2. ; ; ; (, Environmental Research Letters)
    Abstract The ocean has absorbed about 25% of the carbon emitted by humans to date. To better predict how much climate will change, it is critical to understand how this ocean carbon sink will respond to future emissions. Here, we examine the ocean carbon sink response to low emission (SSP1-1.9, SSP1-2.6), intermediate emission (SSP2-4.5, SSP5-3.4-OS), and high emission (SSP5-8.5) scenarios in CMIP6 Earth System Models and in MAGICC7, a reduced-complexity climate carbon system model. From 2020–2100, the trajectory of the global-mean sink approximately parallels the trajectory of anthropogenic emissions. With increasing cumulative emissions during this century (SSP5-8.5 and SSP2-4.5), the cumulative ocean carbon sink absorbs 20%–30% of cumulative emissions since 2015. In scenarios where emissions decline, the ocean absorbs an increasingly large proportion of emissions (up to 120% of cumulative emissions since 2015). Despite similar responses in all models, there remains substantial quantitative spread in estimates of the cumulative sink through 2100 within each scenario, up to 50 PgC in CMIP6 and 120 PgC in the MAGICC7 ensemble. We demonstrate that for all but SSP1-2.6, approximately half of this future spread can be eliminated if model results are adjusted to agree with modern observation-based estimates. Considering the spatial distribution of air-sea CO2fluxes in CMIP6, we find significant zonal-mean divergence from the suite of newly-available observation-based constraints. We conclude that a significant portion of future ocean carbon sink uncertainty is attributable to modern-day errors in the mean state of air-sea CO2fluxes, which in turn are associated with model representations of ocean physics and biogeochemistry. Bringing models into agreement with modern observation-based estimates at regional to global scales can substantially reduce uncertainty in future role of the ocean in absorbing anthropogenic CO2from the atmosphere and mitigating climate change. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Global Biogeochemical Cycles)
    Abstract We assess the Southern Ocean CO2uptake (1985–2018) using data sets gathered in the REgional Carbon Cycle Assessment and Processes Project Phase 2. The Southern Ocean acted as a sink for CO2with close agreement between simulation results from global ocean biogeochemistry models (GOBMs, 0.75 ± 0.28 PgC yr−1) andpCO2‐observation‐based products (0.73 ± 0.07 PgC yr−1). This sink is only half that reported by RECCAP1 for the same region and timeframe. The present‐day net uptake is to first order a response to rising atmospheric CO2, driving large amounts of anthropogenic CO2(Cant) into the ocean, thereby overcompensating the loss of natural CO2to the atmosphere. An apparent knowledge gap is the increase of the sink since 2000, withpCO2‐products suggesting a growth that is more than twice as strong and uncertain as that of GOBMs (0.26 ± 0.06 and 0.11 ± 0.03 Pg C yr−1 decade−1, respectively). This is despite nearly identicalpCO2trends in GOBMs andpCO2‐products when both products are compared only at the locations wherepCO2was measured. Seasonal analyses revealed agreement in driving processes in winter with uncertainty in the magnitude of outgassing, whereas discrepancies are more fundamental in summer, when GOBMs exhibit difficulties in simulating the effects of the non‐thermal processes of biology and mixing/circulation. Ocean interior accumulation of Cantpoints to an underestimate of Cantuptake and storage in GOBMs. Future work needs to link surface fluxes and interior ocean transport, build long overdue systematic observation networks and push toward better process understanding of drivers of the carbon cycle. 
    more » « less
  4. ; ; (, Proceedings of the National Academy of Sciences)
    Through biological activity, marine dissolved inorganic carbon (DIC) is transformed into different types of biogenic carbon available for export to the ocean interior, including particulate organic carbon (POC), dissolved organic carbon (DOC), and particulate inorganic carbon (PIC). Each biogenic carbon pool has a different export efficiency that impacts the vertical ocean carbon gradient and drives natural air–sea carbon dioxide gas (CO2) exchange. In the Southern Ocean (SO), which presently accounts for ~40% of the anthropogenic ocean carbon sink, it is unclear how the production of each biogenic carbon pool contributes to the contemporary air–sea CO2exchange. Based on 107 independent observations of the seasonal cycle from 63 biogeochemical profiling floats, we provide the basin-scale estimate of distinct biogenic carbon pool production. We find significant meridional variability with enhanced POC production in the subantarctic and polar Antarctic sectors and enhanced DOC production in the subtropical and sea-ice-dominated sectors. PIC production peaks between 47°S and 57°S near the “great calcite belt.” Relative to an abiotic SO, organic carbon production enhances CO2uptake by 2.80 ± 0.28 Pg C y−1, while PIC production diminishes CO2uptake by 0.27 ± 0.21 Pg C y−1. Without organic carbon production, the SO would be a CO2source to the atmosphere. Our findings emphasize the importance of DOC and PIC production, in addition to the well-recognized role of POC production, in shaping the influence of carbon export on air–sea CO2exchange. 
    more » « less
  5. ; ; (, Science Advances)
    The prevailing hypothesis for lower atmospheric carbon dioxide (CO 2 ) concentrations during glacial periods is an increased efficiency of the ocean’s biological pump. However, tests of this and other hypotheses have been hampered by the difficulty to accurately quantify ocean carbon components. Here, we use an observationally constrained earth system model to precisely quantify these components and the role that different processes play in simulated glacial-interglacial CO 2 variations. We find that air-sea disequilibrium greatly amplifies the effects of cooler temperatures and iron fertilization on glacial ocean carbon storage even as the efficiency of the soft-tissue biological pump decreases. These two processes, which have previously been regarded as minor, explain most of our simulated glacial CO 2 drawdown, while ocean circulation and sea ice extent, hitherto considered dominant, emerge as relatively small contributors. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email