Planetary Sustainability

ADVANCES IN BIOMASS-DERIVED CARBON FOR INTEGRATED CARBON CAPTURE SYSTEMS

2026-02-23T14:06:02+08:00

Biomass-derived carbon materials are gaining prominence as next-generation sorbents for low-carbon and economically viable CO2 capture, owing to their tunable architectures, renewable origins, and strong life-cycle advantages. Much like transforming raw clay into a finely crafted ceramic through controlled firing, these materials evolve through carefully designed synthesis and activation routes that dictate their pore structure, surface chemistry, and ultimately their adsorption performance. This review consolidates recent advances in the mechanisms, synthesis pathways, activation methodologies, and sustainability considerations, shaping their development within integrated carbon capture systems. Hydrothermal carbonisation (HTC) in the 200°C to 260°C range plays a critical role in tailoring surface area and microstructure. The chemical activation consistently delivers superior performance, averaging CO2 uptake values of 2.86 mmol/g, notably higher than 1.85 mmol/g obtained via physical activation. Life-cycle assessments highlight the potential for near-neutral or even negative net emissions, particularly when biomass residues are utilised as the energy source for activation. Techno-economic evaluations further reveal competitive removal costs that outperform those of conventional amine-based systems, driven by lower regeneration energy requirements and reduced capital costs. Collectively, this review uniquely integrates mechanistic understanding, activation-performance benchmarking, and sustainability evidence to establish clear design and deployment pathways for biomassderived carbons in integrated carbon capture systems.

CAN HYDROTHERMAL BIOMASS PROCESSING SERVE AS AN ANALOGUE OF MILLENNIA-SCALE NATURAL CARBON MATURATION? A UNIFIED PERSPECTIVE ON CARBONISATION, HUMIFICATION, AND FULVIFICATION

2026-02-23T14:05:49+08:00

Hydrothermal biomass processing provides a rapid and controllable approach to replicating the natural carbon maturation of organic matter, a process that typically spans millennia. Subcritical water treatment at elevated temperatures and pressures converts biomass into products analogous to those found in peat, lignite, and coal. This review examines three principal hydrothermal pathways, namely carbonisation, humification, and fulvification, which yield hydrochar, artificial humic acids, and fulvic-like acids, respectively. These products share similarities with natural soil organic matter in terms of carbon content, polarity, and stability. The Van Krevelen diagram serves as a valuable tool for comparing the transformation trajectories of these materials with those of natural carbon evolution. Analysing the effects of process variables such as temperature, pH, and feedstock composition facilitates the development of tailored carbon materials for soil amendment, peat substitution, and carbon sequestration. The review also addresses technological challenges and scaleup requirements to advance future bioeconomy applications.

WHY AQUACULTURE MUST REDUCE ITS DEPENDENCE ON FISHMEAL

2026-02-23T14:05:36+08:00

Aquaculture, as the world’s fastest-growing food production sector is indispensable for global food security and nutrition. Yet, its environmental and economic sustainability is critically jeopardised by a deep-seated reliance on fishmeal, a finite resource derived from wild-caught forage fisheries. This comprehensive review argues that reducing this dependency is an urgent imperative, synthesising evidence from 2020 onward across environmental, economic, and social dimensions. The overexploitation of small pelagic fish for reduction to meal disrupts marine trophic webs, compromises ecosystem resilience, and conflicts with direct human consumption needs in vulnerable regions. Economically, it binds the industry to volatile commodity markets, threatening profitability and stability. The article meticulously evaluates the scientific and commercial progress in alternative proteins, including precision-formulated plant blends, insect meals, single-cell proteins, and by-product valorisation, demonstrating that viable pathways exist. Through detailed case studies and policy analysis, it concludes that a systemic transition toward circular aquafeed systems is not only feasible but essential. This transition, supported by coherent policy, targeted R&D, and market incentives, is the key to unlocking aquaculture’s potential as a truly sustainable, resilient, and equitable pillar of the future global food system, aligning with the United Nations (UN) Sustainable Development Goals.

FROM SMOG TO STEWARDSHIP: THE “DUAL-LOOP” GOVERNANCE MODEL FOR PLANETARY SUSTAINABILITY DRIVEN BY WOMEN’S LEADERSHIP IN FUKUOKA, JAPAN

2026-02-23T14:05:21+08:00

As cities worldwide confront the escalating challenges of the Anthropocene, Fukuoka, Japan, exemplifies a transformative approach shaped by both top-down directives and grassroots leadership. Notably, women have played a pivotal role in redefining environmental governance through care, scientific engagement, and entrepreneurship. This review analyses Fukuoka’s sustainability trajectory through the frameworks of planetary Health and One Health. The “Dual-Loop” Governance Model is introduced, consisting of a technological Macro Loop and a social Micro Loop. By integrating historical policy records, quantitative disaster resilience data (JDA-DAT), and educational
curricula from Fukuoka Women’s University (FWU), this article demonstrates the institutionalisation of women’s agency into professional competency. While recognising the interaction between administrative and technological factors, the analysis indicates that the Micro Loop, led by women, substantially enhances system efficacy. The Fukuoka model is presented as a potential blueprint for other Asian cities, contingent upon specific administrative capacities and community structures.

ENGINEERING NITROGENASE FOR PLANETARY SUSTAINABILITY: RENEWABLE-POWERED BIOHYBRID AMMONIA AND THE ROAD BEYOND HABER–BOSCH

2026-02-23T14:05:07+08:00

The Haber–Bosch process made synthetic ammonia abundant and helped feed a growing population, but it also created a sustainability debt: Substantial fossil-energy demand, significant CO2 emissions, and pervasive nitrogen losses that drive eutrophication and N2O emissions. Biological nitrogen fixation (BNF) is attractive because nitrogenase reduces N2 to NH3 at ambient conditions, yet the enzyme’s oxygen lability, complex metallocluster biosynthesis, and high energy demand complicate implementation beyond its native microbial contexts. This review synthesises three routes to reduce fertiliser dependence: Engineered nitrogen-fixing biofertilisers that excrete ammonium; plant-centred strategies that extend symbiosis or express nitrogenase components in organelles; and, purified nitrogenase or biohybrid systems powered by renewable electricity or light. We emphasise biohybrid devices because they decompose the challenge into modular interfaces (enzyme, power, microreactor environment) but require credible solutions for wiring, stability, continuous operation, and product capture. Across routes, protein engineering for stability, interface tolerance, and electron delivery is a shared enabling lever for system-level impact.