Review Report of CARBOCEAN Michael Krom and Victor Brovkin

Preamble We very much want to thank you for inviting us to your annual meeting. This is a very large and complex project. Being able to come here, put faces to names and to hear first hand some of the exciting and socially relevant science you are doing will make our job of reviewing your annual report(s) that much easier.

Preamble Our comments are initially based on our comments on the report you submitted last year. We have added some extra thoughts but we are very conscious that we do not want to prejudge your next report based on what we have heard yesterday.

Overall assessment: The project shows good to excellent progress in most of the activities There are several notable scientific achievements including the calculated reduction in CO2 flux to the N.Atlantic which I presume is the same information that hit the UK national headlines a few weeks ago. We noted that most work packages reached their stated objectives except for WP10 We complimented you on raising complimentary funding to take forward several ideas and projects. Noted that you have shown flexibility in adding extra deliverables in the region of acidification of surface waters in particular.

Overall assessment: Recommendations Evaluation of future oceanic carbon sink is even more important now because of declaration of climate stabilization target by European Council. Consequently, assessment of ocean uptake in case of climate stabilization might be addressed in more details in the project Monitor the situation in WP10 carefully and if necessary make changes to deal with the problems which are occurring in building and deploying the floats Asked for an improvement in the reporting from WP13.

Objectives: The overall objectives remain relevant and achievable Main objective of the description phase (month 1-18) - reference description – has been achieved We complimented you on the effort being made to carry out high quality AQC on the historical and new data sets.

Workplan and Resources: The project progress is very good and management are to be congratulated in keeping such a large and complex programme on track. Where work programmes are delayed, the delays were satisfactorily explained and problems allowed for.

Work planned for the next 18- month period The plan seemed to be well thought out. The plans for non-scientific activities seemed to be going well.

Consortium partnership: Collaboration has been effective. We especially noted the coordination between observational scientists and modellers and between scientists and those involved in making the results available to the general public.

Management: Excellent An active interactions with the other relevant EC projects such as CARBOEUROPE (WP 14) –An integration of oceanic and terrestrial datasets (even with some delay) will be a highlight of both IPs Good involvement with other major international programmes particularly with the USA

Use and dissemination of knowledge: The recent information about the reduction in CO2 uptake by the global ocean shows this is taking place adequately. List of publications and submitted manuscripts is impressive. Web site of the project has been greatly improved.

Policy-relevant questions In case of climate (and CO 2 ) stabilization, how rapid is a decline of the ocean carbon uptake? Could we better constrain uncertanties in mechanisms of the ocean carbon uptake (physical advection, biological pump)?

Postscript Be careful in how data is transferred from experimental scientists to modellers. Particularly the very interesting data from the Bergen microcosm experiment can be misinterpreted by climate modellers such as those I work with to mean that the Redfield ratio is no longer valid in a changing world.