This week’s publication highlights cover a wide range of topics such as carbon removal obligations in Canada, marine carbon dioxide removal and storage, carbon capture and storage, atmospheric cdr and carbon offsetting.
Applying Equity Principles Leads to Higher Carbon Removal Obligations in Canada
Abstract
Despite net-zero pledges, consensus on national responsibilities for carbon dioxide removal (CDR) strategies is lacking. Here, we use integrated assessment modeling to examine equity-informed estimates of Canada’s remaining carbon budgets, exploring CDR’s role at net-zero and beyond. Gigaton-scale CDR efforts post-2050 are needed to address Canada’s carbon debt under various burden-sharing principles. Cumulative negative emissions (2050-2100) could increase from 7.5 GtCO2 in the Net-Zero scenario to 20.3 GtCO2 in equity-informed scenarios. By 2100, a CDR portfolio, including bioenergy with carbon capture and storage, direct air capture, and enhanced weathering could contribute up to ~500 MtCO2/year of removals. The projected average CDR growth rates, 2.8%-16%/year, align with the historical adoption rates of ammonia synthesis and biomass consumption in Canada, underscoring the importance of drawing lessons from past successes. Socio-economic and technological sensitivity analysis highlights that, despite variations in the role of individual CDR technologies, CDR remains essential for Canada’s post-net-zero commitments.
Motlaghzadeh, K. et al. (2025) Applying Equity Principles Leads to Higher Carbon Removal Obligations in Canada. 88 (6) Communications Earth & Environment.
Read the full paper here: Applying Equity Principles Leads to Higher Carbon Removal Obligations in Canada I Communications Earth & Environment.
The Science, Engineering, and Validation of Marine Carbon Dioxide Removal and Storage
Abstract
Scenarios to stabilize global climate and meet international climate agreements require rapid reductions in human carbon dioxide (CO2) emissions, often augmented by substantial carbon dioxide removal (CDR) from the atmosphere. While some ocean-based removal techniques show potential promise as part of a broader CDR and decarbonization portfolio, no marine approach is ready yet for deployment at scale because of gaps in both scientific and engineering knowledge. Marine CDR spans a wide range of biotic and abiotic methods, with both common and technique-specific limitations. Further targeted research is needed on CDR efficacy, permanence, and additionality as well as on robust validation methods—measurement, monitoring, reporting, and verification—that are essential to demonstrate the safe removal and long-term storage of CO2. Engineering studies are needed on constraints including scalability, costs, resource inputs, energy demands, and technical readiness. Research on possible co-benefits, ocean acidification effects, environmental and social impacts, and governance is also required.
Doney, S. et al. (2025) The Science, Engineering, and Validation of Marine Carbon Dioxide Removal and Storage. 17 Annual Review of Marine Science.
Read the full paper here: The Science, Engineering, and Validation of Marine Carbon Dioxide Removal and Storage I Annual Review of Marine Science.
Global Carbon Capture and Storage Efforts: Challenges and Opportunities
Abstract
Fossil fuels account for around 80% of global energy consumption, making their reduction and replacement a significant challenge. The burning of fossil fuels primarily for power, heating and vehicular transport is the single largest source of CO2 emissions globally (Allan et al., 2021). Besides, heavy industries such as steel production, cement manufacturing and chemical processing also rely heavily on fossil fuels, leading to additional CO2 emissions. According to the 2024 Global Carbon Budget report by the Global Carbon Project, CO2 emissions from fossil fuels and cement rose around 0.8% in 2024, reaching a record 37.4 bn tonnes of CO2 (GtCO2). This is 0.4 GtCO2 higher than the previous record, set in 2023. According to these accounts the total CO2 emissions – including both fossil and land-use emissions – will also set a new record at 41.6 GtCO2, a growth of 2% over 2023 levels. Over the last decade, land-use change CO2 emissions have declined on average but fossil CO2 emissions have risen sharply. China’s emissions (32% of the global total) are projected to marginally increase by 0.2%, while that for the US (13% of the global total) and European Union (7% of the global total) are projected to decrease by 0.6% and 3.8% respectively. India’s emissions (8% of the global total) are on the other hand projected to increase by 4.6%. Efforts to reduce reliance on fossil fuels include increasing the use of renewable energy sources (like wind, solar and hydroelectric power), improving energy efficiency, and implementing carbon capture and storage technologies.
Duraiswami, R. (2025) Global Carbon Capture and Storage Efforts: Challenges and Opportunities 101 (2) Journal of the Geological Society of India.
Read the full paper here: Global Carbon Capture and Storage Efforts: Challenges and Opportunities I Journal of the Geological Society of India.
Combining Eddy Covariance Towers, Field Measurements, and the MEMS 2 Ecosystem Model Improves Confidence in the Climate Impacts of Bioenergy With Carbon Capture and Storage
Abstract
Carbon dioxide removal technologies such as bioenergy with carbon capture and storage (BECCS) are required if the effects of climate change are to be reversed over the next century. However, BECCS demands extensive land use change that may create positive or negative radiative forcing impacts upstream of the BECCS facility through changes to in situ greenhouse gas fluxes and land surface albedo. When quantifying these upstream climate impacts, even at a single site, different methods can give different estimates. Here we show how three common methods for estimating the net ecosystem carbon balance of bioenergy crops established on former grassland or former cropland can differ in their central estimates and uncertainty. We place these net ecosystem carbon balance forcings in the context of associated radiative forcings from changes to soil N2O and CH4 fluxes, land surface albedo, embedded fossil fuel use, and geologically stored carbon. Results from long term eddy covariance measurements, a soil and plant carbon inventory, and the MEMS 2 process-based ecosystem model all agree that establishing perennials such as switchgrass or mixed prairie on former cropland resulted in net negative radiative forcing (i.e., global cooling) of −26.5 to −39.6 fW m−2 over 100 years. Establishing these perennials on former grassland sites had similar climate mitigation impacts of −19.3 to −42.5 fW m−2. However, the largest climate mitigation came from establishing corn for BECCS on former cropland or grassland, with radiative forcings from −38.4 to −50.5 fW m−2, due to its higher plant productivity and therefore more geologically stored carbon. Our results highlight the strengths and limitations of each method for quantifying the field scale climate impacts of BECCS and show that utilizing multiple methods can increase confidence in the final radiative forcing estimates.
Falvo, G. et al. (2025) Combining Eddy Covariance Towers, Field Measurements, and the MEMS 2 Ecosystem Model Improves Confidence in the Climate Impacts of Bioenergy With Carbon Capture and Storage. 17(3) GCG Bioenergy.
Read the full paper here: Combining Eddy Covariance Towers, Field Measurements, and the MEMS 2 Ecosystem Model Improves Confidence in the Climate Impacts of Bioenergy With Carbon Capture and Storage I Bioenergy.
Good Economies of Carbon Offsetting: The Cynical Dynamics of valuation and critique in voluntary carbon markets
Abstract
Voluntary carbon markets are based on the idea that the carbon credits sold in markets are both the same, or climatically equivalent to one another, and different, reflecting how, when, where, and by whom they have been produced. This article examines how market actors deal with this tension and value units that are both commensurate and differentiated. Based on existing literature, interviews, and document analysis, I identify and present three instantiations of a good economy of carbon offsetting from the 2000s onwards. Each phase shows how valuation processes iterate between commensuration and differentiation. This is achieved through the development of elaborate sets of complementary valuation practices and tools, such as methodologies for valuing co-benefits, impact scores and overcompensation factors for securing climate impacts, and carbon removal crediting methodologies. While critique is central to driving the move from one good economy to another, this article also shows how the valuation practices of voluntary carbon markets appear locked into repetitive cycles of critique and reform, with recurrent disputes emerging over what to weigh and value and how. This poses new questions concerning how to critique such markets and their valuation practices.
Karhunmaa, K. (2025) Good Economies of Carbon Offsetting: The Cynical Dynamics of valuation and critique in voluntary carbon markets 12(1) Valuation Studies.
Read the full paper here: Good Economies of Carbon Offsetting: The Cynical Dynamics of valuation and critique in voluntary carbon markets I Valuation Studies.