There are several major challenges faced in implementing carbon sequestration techniques on a large scale. One of the biggest challenges is the cost associated with capturing and storing carbon dioxide emissions. Carbon capture and storage (CCS) technology is currently very expensive to deploy, requiring significant capital investments in new infrastructure and equipment. The cost of capturing CO2 from large industrial sources like power plants or cement factories can add over 30-100% to the cost of electricity depending on the source and capture technology used. Transportation and storage of large volumes of compressed CO2 also require new pipeline networks or shipping infrastructure which drive up costs further. According to estimates, CCS may need to be implemented on over 5000 large facilities globally to make a sizeable dent in emissions, requiring trillions of dollars in investments. Achieving economy of scale to drastically bring down costs is a major hurdle for commercial and widespread deployment of CCS.

Reliably and safely storing carbon dioxide underground for very long durations, potentially hundreds or thousands of years, poses significant technical challenges. Suitable geological sites need to be identified which have appropriate rock formations with adequate porosity to safely immobilize vast volumes of compressed supercritical CO2 without any risk of leakage back into the atmosphere. Extensive site characterization studies are necessary to understand storage capacity, geomechanics, fluid flow dynamics etc. Monitoring stored CO2 plumes and ensuring no migration or leakages over millennial timescales requires ongoing observations, which also drive up costs. Permanent sequestration security is difficult to guarantee scientifically, with unknown risks from unforeseen geological changes or human intrusions centuries from now. Public acceptance of underground carbon storage also remains weak due to concerns over potential health, environmental or safety risks from future CO2 leaks.

Utilizing captured carbon for enhanced oil recovery (EOR) operations, whereby CO2 is injected into aging oil fields to displace more oil, can improve the economics of CCS to some extent. However, EOR potential is limited by available declining oil fields, with only a fraction of stored CO2 volumes likely to be used this way. Most storage would still require long term geological sequestration without EOR benefits. Lack of existing CO2 transport infrastructure also hampers wider EOR deployment as pipelines need to be laid connecting capture facilities to faraway oil basins. Even with EOR the fundamental challenge of high upfront costs for carbon capture remains unsolved.

Large scale utilization of carbon in products and fuels also faces many challenges compared to geological storage or EOR. Technologies are currently at early stages of development and tend to be small-scale. Captured CO2 has to compete with abundant natural carbon sources for product synthesis. Economic viability at scale against alternatives like renewable energy is uncertain. The carbon dioxide would essentially be circulating in intermediate products before eventual release back to the atmosphere over time. Permanent long term storage targets are harder to achieve compared to underground geological solutions.

Land requirements for important carbon farming and forestry based sequestration techniques can also conflict with pressures on agricultural lands to meet growing food demands. Reliance on biological carbon removal faces significant uncertainties due to climate change impacts on forests and crops. Permanence of terrestrial storage is less guaranteed compared to geological solutions as stored carbon can be re-emitted by processes like forest fires or decomposition after harvesting. Large boosts in annual carbon removal are difficult by these means alone.

Overcoming these various technical, economic, social and environmental challenges is crucial for widespread adoption of carbon sequestration and management of greenhouse gas levels in the atmosphere. Major research and development investments over long periods will be required to significantly bring down costs while assuring safety, public confidence and scale of deployment needed to impact the climate crisis through carbon dioxide removal strategies. Global collaboration on shared technological and infrastructure solutions may help expedite progress, but uncertainties and risks are inevitably high especially given the urgency of climate mitigation needs over the next few decades according to scientific assessments. Carbon sequestration offers potential opportunities but has a very long way to go before being deployed at scales necessary for climate stabilization goals.

High costs, technical and safety uncertainties of long term storage, limited utilisation/storage options, land constraints, permanence issues and lack of infrastructure are some of the major implementation challenges faced for carbon sequestration methods today. Overcoming performance barriers, gaining public trust and deploying at gigatonne scales annually present immense obstacles that will require focused global efforts spanning generations to achieve. The climate problem’s severity and solutions’ complexity therefore demand immediate action along with ongoing improvements in cost, scale and approach to carbon management through technological and wider socio-economic transformation.