Recent research has revealed that the Earth’s capacity to store carbon dioxide underground is far more limited than previously thought. This finding challenges the widespread assumption that geological carbon storage can serve as an almost limitless solution to climate change. The study warns that overreliance on underground storage could undermine global efforts to reduce emissions and meet temperature targets.
About Geological Carbon Storage
Geological carbon storage involves capturing CO2 from industrial sources or directly from the atmosphere. The captured gas is injected deep into sedimentary rock formations. These formations are expected to trap CO2 securely for centuries. This method is considered a key tool in reducing atmospheric greenhouse gases.
Revised Global Storage Capacity
Researchers mapped global sedimentary basins suitable for CO2 storage. They excluded risky areas such as earthquake zones, polar regions, and biodiversity hotspots. Practical constraints like drilling depth and offshore limits were also factored in. The result showed only about 1,460 billion tonnes of CO2 can be safely stored. This is roughly one-tenth of earlier estimates, which suggested 11,800 billion tonnes.
Implications for Climate Targets
Most climate models aiming to limit warming to below 2°C rely heavily on large-scale CO2 storage. The new capacity limit means that, at current rates, this storage could be exhausted by the year 2200. The maximum potential temperature reduction from underground storage alone is about 0.7°C. This indicates that carbon storage cannot reverse global warming by itself.
Unequal Distribution of Storage Capacity
Storage potential varies widely between countries. Russia, the United States, and Saudi Arabia have the largest capacities. India and many European nations have comparatively low storage potential. This uneven distribution raises geopolitical and strategic challenges for global climate cooperation.
Carbon Storage as a Finite Resource
Recognising underground storage as limited forces a rethink of its role. Should it be used to extend fossil fuel use or to remove carbon directly from the air? This ethical and strategic question marks the need for prioritising long-term climate benefits over short-term gains.
Need for Emission Reductions and Renewables
The study emphasises that emission cuts remain the most effective climate action. Carbon storage can assist but cannot replace rapid transitions to renewable energy. Industry changes and protection of natural carbon sinks are also essential. Relying solely on storage risks delaying necessary systemic changes.
Limitations and Future Technologies
The analysis does not consider challenges in scaling up carbon capture and storage technologies. It also excludes potential future innovations that might enhance storage or develop alternative solutions. Thus, ongoing research and technological progress remain critical.
Questions for UPSC:
- Critically discuss the role of geological carbon storage in global climate change mitigation strategies, with examples from different countries.
- Examine the challenges and opportunities of transitioning to renewable energy sources in countries with limited carbon storage capacity.
- With suitable examples, discuss the ethical considerations in prioritising carbon capture and storage versus direct emission reductions.
- Analyse the impact of uneven natural resource distribution on international climate policy cooperation and negotiations.
