In the race against climate change, a technology that promises to turn back the carbon clock is sparking both billion-dollar bets and fierce scientific debate.
Imagine a power plant that generates electricity while simultaneously removing carbon dioxide from the atmosphere. This is the promise of Bioenergy with Carbon Capture and Storage, or BECCS—a technology that has become a cornerstone of many climate models and is now attracting massive investment from tech giants like Microsoft.
More land needed for biomass vs solar/wind for same energy
The concept of BECCS is deceptively simple: plants and trees absorb CO₂ as they grow, making them natural carbon sinks. When this biomass is used to produce energy—whether burned for electricity or processed into biofuels—the carbon is released again. Normally, this would make biomass a carbon-neutral energy source. The game-changer happens when you add carbon capture and storage (CCS) technology to trap those emissions before they reach the atmosphere and permanently store them underground 7 .
The theoretical result? Net-negative emissions: more carbon is removed from the atmosphere than is released throughout the process 6 .
The appeal of this technology in climate policy circles is immense. According to United Nations climate assessments, to limit global warming to 2°C, the world may need to remove 11 billion tons of CO₂ annually by 2050 8 . BECCS appears to offer a way to achieve this while simultaneously producing energy—addressing two challenges at once.
"If we're balancing cost, time to market, and ultimate scale potential, BECCS offers a really attractive value proposition across all three of those dimensions."
Plants and trees absorb CO₂ from the atmosphere through photosynthesis.
Biomass is collected and transported to energy production facilities.
Biomass is burned or processed to generate electricity or biofuels.
CO₂ emissions are captured from the flue gas before release to atmosphere.
Captured CO₂ is transported and permanently stored underground.
Despite its theoretical appeal and growing political traction, BECCS faces significant scientific skepticism. The fundamental issue lies in the carbon accounting behind biomass energy.
"If you're harvesting wood, it's essentially impossible to get negative emissions. Some BECCS approaches are a form of folly."
The criticism centers on several often-overlooked factors in the biomass lifecycle:
After forests are harvested, it takes decades for new growth to reabsorb the released carbon .
Fossil fuels burned during cutting, collecting, and transporting biomass add to the carbon footprint 6 .
The harvested trees would have continued absorbing carbon if left standing 6 .
Carbon left behind in roots or branches decomposes and releases greenhouse gases 6 .
The European Academies' Science Advisory Council (EASAC) emphasizes that the delay in achieving genuine carbon reduction may be "too long to contribute to meeting Paris Agreement targets" .
| Proponents' View | Skeptics' Concerns |
|---|---|
| Biomass is carbon-neutral because new growth reabsorbs CO₂ | Carbon payback periods can span decades, creating a "carbon debt" |
| BECCS achieves negative emissions when CCS is added | Supply chain emissions from harvesting and transport are often excluded from calculations |
| Sustainable forest management ensures carbon balance | The focus on stem wood ignores carbon stored in roots, soils, and forest floor |
| Carbon credits can accurately reflect removal | Overlooks the opportunity cost of not leaving forests to continue sequestering carbon |
Beyond the carbon accounting debate, BECCS faces significant practical challenges related to scale and efficiency.
Biomass requires 50-100 times more land than solar or wind for the same energy output .
The energy required for carbon capture creates a "parasitic energy cost"—significantly reducing the net energy output of BECCS plants . There's a fundamental trade-off between how much CO₂ is captured and the extra energy required in the capture and storage process .
Research indicates that generating energy from biomass requires 50-100 times more land than solar or wind power to produce the same amount of energy . With competing demands for food production, ecosystem restoration, and biodiversity conservation, dedicating vast land areas to biomass production may be unsustainable.
International Energy Agency suggests around 5 gigatonnes of biomass might be available globally each year .
Other estimates that account for sustainability criteria are even lower than current projections .
Demands for wood materials, pulp, paper, and bioplastics are expected to increase, creating competition for resources .
While debates about traditional BECCS continue, scientists are exploring innovative hybrid approaches that integrate biological and chemical processes. A 2025 study published in Scientific Reports investigated a novel method for carbon dioxide removal from triethanolamine solution using living microalgae-loofah biocomposites 9 .
Researchers created living biocomposites by immobilizing Scenedesmus acuminatus microalgae on loofah material using a 5% acrylic medium as a binder 9 .
The team prepared 1 M triethanolamine (TEA) solutions with varying CO₂ loading ratios (0.2, 0.4, 0.6, and 0.8 mol CO₂/mol TEA) 9 .
The biocomposites were exposed to the CO₂-rich TEA solutions, with performance compared against traditional suspended microalgae systems over 28 days 9 .
The microalgae-loofah biocomposites dramatically outperformed conventional systems, achieving CO₂ removal rates 3 to 5 times higher than the suspended cell approach 9 . The highest removal was observed at the 1 M TEA with 0.4 mol CO₂/mol TEA loading ratio—reaching 4.34 ± 0.20 gCO₂ per gram of biomass 9 .
| System Type | CO₂ Removal Rate | Optimal Conditions |
|---|---|---|
| Microalgae-loofah biocomposites | 3-5x higher than suspended systems | 1 M TEA with 0.4 mol CO₂/mol TEA |
| Traditional suspended microalgae | Baseline for comparison | Same conditions |
| Previous amine regeneration | Energy-intensive thermal process | High temperature, high energy cost |
This experiment is significant because it addresses one of the major limitations of conventional amine-based carbon capture: the high energy cost of solvent regeneration, which accounts for 57-70% of the total energy requirement 9 . By using microalgae to regenerate the amine solvent biologically, the approach could potentially eliminate this energy penalty while simultaneously producing valuable biomass.
| Tool/Technology | Function in Research | Current Status/Challenge |
|---|---|---|
| Amine solvents (e.g., TEA, MEA) | Chemical absorption of CO₂ from gas streams | High regeneration energy; solvent degradation |
| Microalgae-biocomposites | Biological regeneration of amines; CO₂ conversion to biomass | Early R&D stage; scaling challenges |
| Carbon mineralization | Permanent CO₂ storage as stable carbonate minerals | Natural process being accelerated through engineering |
| Geological storage | Permanent sequestration of captured CO₂ in underground formations | Limited by infrastructure and public acceptance |
| Biochar | Pyrolysis of biomass to create stable carbon-rich charcoal | Carbon-negative; but limited scale compared to needs |
As the climate crisis intensifies, the search for effective carbon removal technologies becomes increasingly urgent. BECCS represents both a promising concept and a cautionary tale about the complexity of engineering natural processes.
The European Academies' Science Advisory Council recommends focusing on waste-to-energy BECCS options using municipal or agricultural waste, rather than dedicated biomass crops from forests .
BECCS projects should be "of limited scale, all feedstocks provided locally with very low supply chain emissions, and feedstock payback times should be very short" .
"The point is you won't grow new material to do this in most cases, and won't have to for a very long time, because there's so much waste available."
What emerges from the scientific literature is a clear message: BECCS is not the silver bullet that will single-handedly solve climate change. The technology may have a role to play, particularly when using genuine waste streams, but banking on massive future deployments to compensate for inadequate emissions reductions today places significant risks on future generations .
In the end, the story of BECCS reflects a broader truth about climate solutions: there are no easy answers. The most effective approach will likely involve a diverse portfolio of solutions—including emissions reduction, renewable energy, and multiple forms of carbon removal—implemented with careful attention to their full lifecycle impacts. As we navigate this complex landscape, maintaining scientific rigor in evaluating these technologies is as important as the urgency with which we deploy them.
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