Co₂-Capturing microbes: An emerging solution for sustainable cities
- Li Tan
- 6 days ago
- 4 min read
Cities are among the largest contributors to carbon emissions, yet they also offer some of the most fertile ground for climate innovation. A recent scientific development suggests that carbon-fixing microbes—tiny organisms adapted to thrive in extreme urban environments—may hold the key to transforming buildings and infrastructure into tools for atmospheric CO₂ removal. This cutting-edge research supports several UN Sustainable Development Goals (SDGs), including SDG 13 (Climate Action), SDG 11 (Sustainable Cities and Communities), and SDG 9 (Industry, Innovation and Infrastructure).
The drive to integrate nature-based solutions into urban planning has gained momentum, and microbial carbon capture could become a cornerstone of future low-carbon cities. Compact, efficient, and adaptable to harsh conditions, these microbes may provide a viable alternative to traditional carbon sequestration strategies that depend heavily on space, climate, or intensive maintenance.
Urban microbes that capture carbon
A study published in Nature Communications in April 2025, led by researchers from Yale University and the Max Planck Institute for Marine Microbiology, identifies several strains of cyanobacteria and autotrophic bacteria capable of removing atmospheric CO₂ under urban conditions. These microbes not only survive but flourish on surfaces such as rooftops and concrete facades—areas typically considered inhospitable to life.
Using Rubisco, the key enzyme in photosynthetic carbon fixation, alongside efficient metabolic alternatives like the 3-hydroxypropionate cycle, these organisms can convert CO₂ into biomass while releasing oxygen. Their ability to function in fluctuating light, high temperatures, and polluted air sets them apart from traditional green infrastructure such as trees and shrubs.
Bio-integrated designs for climate-friendly cities
Unlike conventional carbon sinks that require substantial space and upkeep, photosynthetic microbes can be applied to vertical surfaces, embedded in materials, or integrated into modular structures. Several concepts are now moving from theory into practice:
· Living biofilms: Thin layers of carbon-fixing microbes embedded in construction materials, applied to walls or rooftops to improve air quality and mitigate heat.
· Modular urban bioreactors: Installations on bus shelters or public furniture that capture carbon and produce biomass for industrial or agricultural use.
· Bioactive paints: Companies like GreenLoop BioSystems are developing paints using algae and bacteria that continuously absorb CO₂ and regenerate with ambient moisture.
These solutions offer scalable models for cities that need flexible, low-maintenance approaches to reduce emissions and foster sustainable infrastructure.
Global pilot projects show early success
Cities across the globe are already experimenting with these systems. In Singapore, microbial green roofs developed at Nanyang Technological University are reducing building temperatures while actively sequestering carbon. In Berlin, the “Living Walls” project has installed biopanels on buildings, capturing and measuring real-time CO₂ levels. Mexico City, one of the world’s most polluted capitals, has implemented algae columns via Biourban, reporting CO₂ reductions of up to 20% in high-traffic zones.
These small-scale pilots demonstrate the practicality and promise of microbial carbon capture, especially in urban contexts where space and climate constraints limit the effectiveness of traditional greenery.
Barriers to mainstream adoption
Despite their potential, technical and regulatory challenges remain:
· Microbial stability: Maintaining a healthy microbial community on exposed urban surfaces is complex, requiring further study to ensure long-term viability.
· Efficiency benchmarks: The overall carbon capture rate must be evaluated against existing green and mechanical alternatives to confirm large-scale impact.
· Public acceptance and policy gaps: Many governments lack clear regulations for biological infrastructure, and public understanding of “living surfaces” is limited.
Addressing these issues will be crucial to moving from experimental deployments to widespread urban integration.
Global cooperation and knowledge sharing
The role of the Global Society is critical in driving innovation and creating pathways for international collaboration. Programmes such as the EU Horizon 2020 Living Architecture Project and platforms like the MIT Climate Portal are enabling scientists, architects, and policymakers to exchange knowledge, build frameworks, and scale solutions.
Partnerships across regions and sectors are essential not only to refine microbial technologies but also to support their deployment in diverse climates and socio-economic contexts. Global collaboration ensures that innovations are inclusive, effective, and aligned with broader sustainability goals.
The path forward
As cities seek urgent solutions to the climate crisis, CO₂-capturing microbes offer a fascinating blend of science and sustainability. These living systems, capable of turning grey infrastructure green, represent a forward-looking approach to building climate-resilient, healthier, and more sustainable cities.
Continued investment, research, and global coordination will be vital in unlocking the full potential of microbial carbon capture. By embracing nature at the micro level, cities may take a significant step toward meeting their emissions targets and realising the ambitions of the UN 2030 Agenda.
To explore more about microbial carbon capture and sustainable urban solutions, visit:
Microbial innovation may be small in scale, but its impact on sustainable cities could be profound.
