This week’s publication highlights relate to direct air capture, marine CDR, forestation and bioenergy with carbon capture and storage.
Direct Air Capture and Photoconversion of CO2 to Ethylene by Defect-Tailored CU3-Based Metal-Organic Frameworks
Abstract
The development of efficient direct air capture (DAC) systems coupled with photocatalytic CO2 conversion is still an appealing challenge. Here, we engineered a series of defective Cu3-based metal–organic frameworks (Cu3-MOFs) for integrated atmospheric CO2 capture and in situ photoreduction. The defective Cu3-MOFs were constructed through selective removal of coordinated CO32− from pristine MOFs with HCl etching, generating unsaturated Cu active sites for CO2 harvesting, and the Cu3-MOFs demonstrated enhanced CO2 capture kinetics and capacity that compared to their pristine counterpart. Remarkably, the captured CO2 could be directly photoreduced to C2H4 with an optimal production rate of 18.25 µmol·g−1·h−1 without additional photosensitizer or sacrificial agent. The experimental and theoretical results revealed that the defective sites not only facilitated CO2 adsorption but also promoted C–C coupling of *CO intermediates, thereby enhancing C2H4 production. This work provides deep insights for designing advanced materials toward direct air-to-fuel conversion.
He, Y. et al. (2025) Direct Air Capture and Photoconversion of CO2 to Ethylene by Defect-Tailored CU3-Based Metal-Organic Frameworks 65 (5) Angewandte Chemie International Edition.
Read the full paper here: Direct Air Capture and Photoconversion of CO2 to Ethylene by Defect-Tailored CU3-Based Metal-Organic Frameworks I Angewandte Chemie International Edition.
Blue Carbon in the Persian Gulf: Evidence of Phytoplankton Contribution to Carbon in Sediments
Abstract
Blue carbon ecosystems, such as mangroves, seagrasses, and tidal marshes, are critical for carbon sequestration and climate change mitigation to ensure environmental sustainability. This study provides a review of the limited inventories of blue carbon habitats in the Persian/Arabian Gulf, highlighting limited spatial and temporal coverage as well as the uncertainties in estimates that are quantified using inconsistent methodologies and satellite resolution limitations. The main focus of this paper is a discussion on the consideration of phytoplankton in blue carbon dynamics, which remains understudied, in the Gulf. To underpin the evidence of phytoplankton permanent burial in marine sediments, shotgun metagenomic sequencing was used and 26 phytoplankton species were identified in sediment cores, showing the dominance of Aureococcus anophagefferens and Thalassiosira pseudonana, and underscoring their potential role in carbon sequestration in the northern Gulf, though their inclusion in blue carbon frameworks is complicated by taxonomic diversity and uncertain sequestration pathways. The permanent burial of phytoplankton in these shallow marine and coastal areas brings an important discussion on their inclusion in blue carbon estimates. The use of remotely sensed data for blue carbon habitat mapping needs standardisation and the use of high spatial and spectral resolution remote sensing to improve blue carbon assessments in the region. This study provides firm evidence of phytoplankton presence using eDNA calls for refining the carbon accounting frameworks in the Gulf and beyond, underscoring the importance of refining blue carbon assessments to support evidence-based environmental sustainability and climate action. By integrating phytoplankton contributions into carbon sequestration, more realistic and inclusive frameworks can be developed, enhancing regional strategies for climate change mitigation and coastal ecosystem conservation.
Uddin, S. et al. (2026) Blue Carbon in the Persian Gulf: Evidence of Phytoplankton Contribution to Carbon in Sediments 18 (2) Sustainability.
Read the full paper here: Blue Carbon in the Persian Gulf: Evidence of Phytoplankton Contribution to Carbon in Sediments I Sustainability.
Earth System Model Analysis of How Astronomical Forcing Is Imprinted Onto the Marine Geological Record: The Role of the Marine Organic Carbon Cycle and Feedbacks
Abstract
Eccentricity cycles in deep-sea paleoclimate records suggest that astronomical forcing notably altered global temperatures and carbon cycle dynamics. Because changes in the distribution of insolation alone cannot explain the observed climate variability, climate-carbon cycle feedbacks must have amplified the response. However, the carbon sources and sinks operating on orbital timescales are poorly understood, especially in absence of dynamic ice sheets as during the early Cenozoic. Here, we use an Earth system model to explore the impact of astronomical forcing on the organic carbon cycle and its expression in key paleoceanographic variables, building on Vervoort et al. (2024, https://doi.org/10.1029/2023pa004826) who outlined the role of inorganic carbon cycle feedbacks. Results demonstrate that subtle changes in marine organic carbon burial, driven by nutrient (phosphate, P) availability, can produce 400-kyr cycles of negative δ13C excursions during periods of elevated pCO2 and reduced CaCO3 preservation, consistent with typical orbital variations in Paleocene records. The magnitude and phasing of the response to eccentricity forcing are determined by the balance between P release (via temperature-dependent rock weathering) and P removal (via oxygen-dependent sedimentary P retention). Because these processes are strongly influenced by the distribution of landmasses and shelves, paleogeography exerts a first-order control on the expression of astronomical cycles. We do not reproduce the high amplitude 100-kyr “hyperthermal events” of the early Eocene, but our model identifies two potential mechanisms to amplify global warming on orbital timescales: reduced organic carbon burial as well as enhanced kerogen weathering could increase CO2 during eccentricity maxima under favorable conditions.
Vervoort, P. et al. (2025) Earth System Model Analysis of How Astronomical Forcing Is Imprinted Onto the Marine Geological Record: The Role of the Marine Organic Carbon Cycle and Feedbacks 41(1) Paleoceanography and Paleoclimatology.
Read the full paper here: Earth System Model Analysis of How Astronomical Forcing Is Imprinted Onto the Marine Geological Record: The Role of the Marine Organic Carbon Cycle and Feedbacks I Paleoceanography and Paleoclimatology.
Latitudinal Divergence in Runoff Responses to Global Forestation Due to Forest-Atmosphere Feedbacks
Abstract
Forestation is a pivotal nature-based solution for mitigating global warming, yet its unintended hydrological outcomes and associated geospatial patterns remain understudied. Here, we combine land-atmosphere coupled models with the Budyko framework to show that forest-atmosphere feedbacks dominate a latitudinal divergence in runoff responses induced by global potential forestation, with increases in tropical regions but declines in boreal regions. In tropical regions, substantial precipitation gains due to intensified upward moisture transport overwhelm the negative effects of forest-driven evapotranspiration (ET) enhancement. Conversely, in boreal regions, limited precipitation gains are insufficient to offset enhanced evaporative loss, driven by increased atmospheric demand due to elevated surface net radiation. The negative effects of direct forest expansion vary along the dryness gradient, with peak impacts in energy-water transitional regions. Our study highlights the necessity to incorporate hydrological considerations into carbon- or temperature-focused afforestation planning, and caution afforestation at high-latitudes where new forests may exacerbate water scarcity.
Kan, F. et al. (2026) Latitudinal Divergence in Runoff Responses to Global Forestation Due to Forest-Atmosphere Feedbacks 17 (2515) Nature Communications.
Read the full paper here: Latitudinal Divergence in Runoff Responses to Global Forestation Due to Forest-Atmosphere Feedbacks I Nature Communications.
Techno-Economic Analysis of Waste-to-SAF Pathways with Carbon Capture and Storage and Green Hydrogen Integrations
Abstract
De-fossilising the aviation sector is essential for global climate goals, with sustainable aviation fuels (SAF) identified as a key low-emission solution. Municipal solid waste (MSW), when converted to refuse-derived fuel (RDF), offers an abundant, largely biogenic feedstock for SAF production while diverting waste from landfills. This research study analyses the production of SAF from RDF gasification via bioenergy with carbon capture and storage (BECCS) and power biomass to liquid (PBtL) concepts with Fischer-Tropsch (FT) and Methanol-to-Jet (MTJ) fuel syntheses as production pathways. The processes are modelled within Aspen Plus and single process units are validated against industrial plant data. In the BECCS route, 95% of carbon dioxide (CO₂) is captured post-syngas conditioning and permanently sequestered, enabling potential negative emissions and carbon credits. The PBtL route integrates green hydrogen from water electrolysis for syngas conditioning, with the electrolytic oxygen supporting gasification and reforming. Results show that integrating green H₂ boosts SAF yield but increases energy demand. The MTJ-H2 pathway demonstrated the lowest levelized cost of production of £7.7/kg SAF, although this is still higher than conventional jet fuel and thus not competitive within the current market. As such, policy frameworks and economic incentives remain essential to achieve large-scale deployment of SAF.
Rasheed, M. et al. (2026) Techno-Economic Analysis of Waste-to-SAF Pathways with Carbon Capture and Storage and Green Hydrogen Integrations 283 (108416) Fuel Processing Technology.
Read the full paper here: Techno-Economic Analysis of Waste-to-SAF Pathways with Carbon Capture and Storage and Green Hydrogen Integrations I Fuel Processing Technology.