Climate and Ocean Acidification: Summary Headlines

• Key aspects of the marine climate system are recognised in the IA 2017 common indicators as drivers of ecosystem change, but few have strong causal links and mechanisms identified that would enable an understanding of why an indicator had changed or not changed as a consequence of climate change and climate variability in the ocean, atmosphere and cryosphere.
• In atmospheric science, the use of 're-analysis' is commonplace where historical data and model runs are integrated to give a best estimate of state over decades. Re-analysis of this type is starting to become available for marine climate parameters and could contribute to future assessments.
• Ocean acidification is seen as a key pressure on ecosystems for the future; understanding of its role and the amount of data now available has dramatically increased since the QSR 2010. For the IA 2017 common indicators the assessment is of current status; ocean acidification or pH status are not generally part of those assessments.
• Marine climate / prevailing conditions should be part of the cumulative effects framework where possible. The multi-metric indices built into the benthic habitat indicator identify the potential for marine climate system drivers to be integrated into indicator assessments as part of a cumulative effects approach. As cumulative effects approaches are developed, marine climate and climate change can be included.
• Building in marine climate and climate change to the OSPAR assessment process has begun and needs to make more progress in order to be able to describe the state of the sea, why it has changed, how it might change in the future and what impacts this may cause.
• While climate change projections extending to the end of this century and beyond are important for long-term planning, shorter-term climate variability over years to decades in the North-East Atlantic will also be important for current management decisions. Developments in modelling and understanding of the climate system are starting to result in shorter-term marine climate predictions that have the potential to be of use in future assessments.