The 2013 Report Card provides an update on the scientific understanding of climate change impacts on our seas. As in previous report cards, changes in ocean climate set the context for evidence of impacts on the Government’s vision for clean, healthy, safe, productive and biologically diverse oceans and seas.
There are some changes to the topics in the 2013 Report Card. Arctic sea-ice has been added as a new topic as it has potential to have impacts for the UK. Shipping now includes ports, and the built structures topic is split into coastal and onshore, and offshore.
The number of reported headlines provided in each theme is reduced in this report card compared with previous years. This is because many topics have shown no, or very little, change since the 2010-2011 Report Card. Across the 33 very diverse topics in this report card, one or a combination of reasons, including the following, may explain the lack of change reported:
- there is no change in the status;
- a change in trend or status cannot be identified due to complexities in analysis and/or interpretation, e.g.:
- Processing time: Collecting, preparing and analysing data over sufficient time periods to establish meaningful trends is challenging. Often findings can only be reported some time after field work has been completed.
- Marine ecosystem response: The responses of organisms and large-scale processes to climate change are too subtle to provide measurable evidence of climate change impacts on a short-term basis.
- no new data or information have become available.
IPCC 5th Assessment Report and UK Climate Projections Update
All of the reports making up the Intergovernmental Panel for Climate Change (IPCC) Fifth Assessment will have been released by the end of 2014. The UK Climate Projections will also have updates available for the marine environment in 2014. These new projections will take time to apply to regional scale impact models of relevance to the UK.
Relative time required to understand climate change driven trends in data
The time that it takes to collect data and recognise a trend varies between all of the topics covered in this card. There are also challenges with attributing these trends directly to climate change. Below we provide two illustrations highlighting some of the issues; the collation of physical time series, and species generation time.
Collation of physical time series: Identifying long-term changes can take more time for some physical processes than others. For example, because the strength of the Atlantic Heat Conveyor varies markedly on a daily basis, a relatively long time series is needed to identify any clear trends. For physical processes such as temperature, where short-term changes are less pronounced, trends can be detected from shorter time series.
Species generation time: The ability to establish a link between climate change and trends in species numbers, distribution, etc. varies depending on a combination of factors and our understanding of the natural dynamics of the different species. For plankton species, which are short-lived and for which there is an existing long time series of data it is relatively easy. For many other organisms further up the food chain that have longer generation times and more complex interactions that need to be taken into consideration, the time required before a link between any changes and either direct or indirect climate change impacts can be confirmed is longer.
Based on Edwards et al. 2010. Multi-decadal oceanic ecological datasets and their application in marine policy and management. Trends in Ecology and Evolution, 25: 602-610.