Sea surface temperature

Assessment versions

Published (reviewed and quality assured)

• No published assessments

Rationale

Justification for indicator selection

Sea surface temperature (SST) is an important physical characteristic of the oceans. SST varies naturally with latitude, being warmer at the equator and coldest in Arctic and Antarctic regions. As the oceans absorb more heat, SST will increase (and heat will be redistributed to deeper water layers).

Increases in SST can lead to an increase in atmospheric water vapour over the oceans, influencing entire weather systems. For Europe, the North Atlantic Ocean plays a key role in the regulation of climate over the European continent by transporting heat northwards and by distributing energy from the atmosphere into the deep parts of the ocean. The Gulf Stream and its extensions, the North Atlantic Current and Drift, partly determine weather patterns over the European continent, including precipitation and wind regimes. One of the most visible physical ramifications of increased temperature in the ocean is the reduced area of sea ice coverage in the Arctic polar region.

Temperature is a determining factor for the metabolism of species, and thus for their distribution and phenology, such as the timing of seasonal migrations, spawning events or peak abundances (e.g. plankton bloom events). There is an accumulating body of evidence suggesting that many marine species and habitats, such as cetaceans in the North Atlantic Ocean, are highly sensitive to changes in SST. Increased temperature may also increase stratification of the water column. Such changes can have a significant influence on vertical nutrient fluxes in the water column, thereby influencing primary production and phytoplankton community structure. Further changes in SST could have widespread effects on marine species and cause the reconfiguration of marine ecosystems.

Scientific references

• IPCC, 2013. Climate Change: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T. F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P. M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.

Indicator definition

• Trend in average sea surface temperature anomaly in the global ocean and in Europe’s regional seas

Units

• Temperature (°C)

Policy context and targets

Context description

In April 2013, the European Commission (EC) presented the EU Adaptation Strategy Package. This package consists of the EU Strategy on adaptation to climate change (COM/2013/216 final) and a number of supporting documents. The overall aim of the EU Adaptation Strategy is to contribute to a more climate-resilient Europe.

One of the objectives of the EU Adaptation Strategy is Better informed decision-making, which will be achieved by bridging the knowledge gap and further developing the European climate adaptation platform (Climate-ADAPT) as the ‘one-stop shop’ for adaptation information in Europe. Climate-ADAPT has been developed jointly by the EC and the EEA to share knowledge on (1) observed and projected climate change and its impacts on environmental and social systems and on human health, (2) relevant research, (3) EU, transnational, national and subnational adaptation strategies and plans, and (4) adaptation case studies.

Further objectives include Promoting adaptation in key vulnerable sectors through climate-proofing EU sector policies and Promoting action by Member States. Most EU Member States have already adopted national adaptation strategies and many have also prepared action plans on climate change adaptation. The EC also supports adaptation in cities through the Covenant of Mayors for Climate and Energy initiative.

In September 2016, the EC presented an indicative roadmap for the evaluation of the EU Adaptation Strategy by 2018.

In November 2013, the European Parliament and the European Council adopted the 7^th EU Environment Action Programme (7^th EAP) to 2020, ‘Living well, within the limits of our planet’. The 7^th EAP is intended to help guide EU action on environment and climate change up to and beyond 2020. It highlights that ‘Action to mitigate and adapt to climate change will increase the resilience of the Union’s economy and society, while stimulating innovation and protecting the Union’s natural resources.’ Consequently, several priority objectives of the 7^th EAP refer to climate change adaptation.

Targets

No targets have been specified.

Related policy documents

• 7th Environment Action Programme
  DECISION No 1386/2013/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 20 November 2013 on a General Union Environment Action Programme to 2020 ‘Living well, within the limits of our planet’. In November 2013, the European Parliament and the European Council adopted the 7 th EU Environment Action Programme to 2020 ‘Living well, within the limits of our planet’. This programme is intended to help guide EU action on the environment and climate change up to and beyond 2020 based on the following vision: ‘In 2050, we live well, within the planet’s ecological limits. Our prosperity and healthy environment stem from an innovative, circular economy where nothing is wasted and where natural resources are managed sustainably, and biodiversity is protected, valued and restored in ways that enhance our society’s resilience. Our low-carbon growth has long been decoupled from resource use, setting the pace for a safe and sustainable global society.’
• Climate-ADAPT: Adaptation in EU policy sectors
  Overview of EU sector policies in which mainstreaming of adaptation to climate change is ongoing or explored
• Climate-ADAPT: Country profiles
  Overview of activities of EEA member countries in preparing, developing and implementing adaptation strategies
• DG CLIMA: Adaptation to climate change
  Adaptation means anticipating the adverse effects of climate change and taking appropriate action to prevent or minimise the damage they can cause, or taking advantage of opportunities that may arise. It has been shown that well planned, early adaptation action saves money and lives in the future. This web portal provides information on all adaptation activities of the European Commission.
• EU Adaptation Strategy Package
  In April 2013, the European Commission adopted an EU strategy on adaptation to climate change, which has been welcomed by the EU Member States. The strategy aims to make Europe more climate-resilient. By taking a coherent approach and providing for improved coordination, it enhances the preparedness and capacity of all governance levels to respond to the impacts of climate change.

Methodology

Methodology for indicator calculation

The current indicator primarily uses information from the Hadley Centre Sea Ice and Sea Surface Temperature (HadISST1) dataset. Information on the Mediterranean for the satellite era is complemented by data from the Copernicus Marine Environmental Monitoring Service (CMEMS).

Methodology for gap filling

Not applicable

Methodology references

• Rayner et al. (2006): Improved analyses of changes and uncertainties in sea surface temperature measured in situ since the mid-nineteenth century: The HadSST2 dataset. Rayner, N. A., Brohan, P., Parker, D. E., Folland, C. K., Kennedy, J. J., Vanicek, M., Ansell, T. J. and Tett, S. F. B., 2006, 'Improved analyses of changes and uncertainties in sea surface temperature measured in situ since the mid-nineteenth century: The HadSST2 dataset', Journal of Climate 19(3), 446–469 (doi: 10.1175/JCLI3637.1).
• CMEMS: Mediterranean Sea - High Resolution L4 Sea Surface Temperature Reprocessed (SST_MED_SST_L4_REP_OBSERVATIONS_010_021). For the Mediterranean Sea- the CNR has reprocessed Pathfinder V5.2 (PFV52) AVHRR data over period Nov 1981-Dec 2012 to provide with daily gap-free maps (L4) at the original PFV52 resolution at 0.0417° x 0.0417°. The data are interpolated through an Optimal Interpolation algorithm.

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• Mediterranean Sea - High Resolution L4 Sea Surface Temperature Reprocessed
• HadISST - Global sea ice and Sea Surface Temperature analyses

Data sources in latest figures

Uncertainties

Methodology uncertainty

Not applicable

Data sets uncertainty

In general, changes related to the physical and chemical marine environment are better documented than biological changes. For example, systematic observations of sea surface temperature began around 1880. More recently, these manual measurements have been complemented by satellite-based observations that have a high resolution in time and a wide geographical coverage, as well as by Argo floats that automatically measure temperature and salinity below the ocean surface. In contrast, the longest available time series of plankton from the Continuous Plankton Recorder (CPR) is around 60 years. Sampling was started in the North Sea in the 1950s and today a network covering the entire North Atlantic Ocean has been established.

Our understanding is improving of how climate change, in combination with the synergistic impacts of other stressors, can cause regime shifts in marine ecosystems, but additional research is still needed to untangle the complex interactions and their effects upon biodiversity. Ecological thresholds for individual species are still only understood in hindsight, i.e. once a change has occurred.

Rationale uncertainty

No uncertainty has been specified