Summary Report of the IEAGHG Workshop – Natural Releases of CO₂: Building Knowledge for CO₂ Storage Environmental Impact Assessments

Publication Overview

The IEAGHG workshop on Natural Releases of CO₂: Building Knowledge for CO₂ Storage Environmental Impact Assessments was held in Maria Laach, Germany, in November 2011 and hosted by CO₂GeoNet and BGR.  The workshop was well attended, with forty seven participants from over ten different countries. Sessions included: Setting the Scene; Releases, Magnitudes and Impacts: Marine Environments and Terrestrial Environments; Mobilisation of Brine and Metals; Near Surface vs. Deep Subsurface Mechanisms and, Monitoring Challenges in Light of Natural Systems.  Due to considerable interest in the workshop and an overly prescribed agenda, poster sessions were included within coffee and lunch breaks, with eight presented posters during the workshop.

Publication Summary

Final discussions highlighted several main knowledge gaps:

• Further understanding of impacts and processes of CO₂ displaced waters.
• Further understanding of physical processes of CO₂ flow in aquifers.
• A need to draw together studies to produce an indicator species database.
• A need for field studies to investigate potential mobilisation of brine and metals.
• A need for more data on long-term impacts of CO₂.
• A need for more data on natural background CO₂ in offshore environments.
• Further understanding of mechanisms in the deep subsurface, particularly in regard to understanding of caprocks, additional barriers and trapping mechanisms; drawing from research in other geological communities.
• There is a need to further understand the association of seismicity with natural accumulations of CO₂.

Participants of the workshop recommend:

• A follow-up meeting given the amount of interest and the workshop establishment of a research community.
• An integrated, international, cross-disciplinary natural analogue/controlled release program given the wide spread of researchers who can impart knowledge to advance knowledge in this critical research area.
• Future and current research needs to integrate modelling, field studies and laboratory research.
• Further research on long-term impacts in marine and terrestrial environments.
• It is important to expand this community to include other areas of relevant research bringing together biologists, geologists and many other experts to advance knowledge, as has clearly happened at this workshop.

This highly productive and informative workshop expresses the importance of such meeting at a time when despite emerged CCS regulations requiring Environmental Impact Assessments uncertainties remain and the research community are asked to advance understanding.