Sea surface temperature (SST) is the water temperature close to the ocean’s surface. The exact meaning of surface varies between 1mm and 20 metres below the sea surface.

A seamount is a mountain rising from the ocean seafloor that does not reach to the water’s surface (sea level), and thus is not an island. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to 1,000-4,000 m (3,300- 13,100 ft) in height.

Any form of ice found at sea which has originated from the freezing of sea water (sea ice does not include superstructure icing). Ice formed from the freezing of the waters of the Great Lakes will be considered the same as sea ice.

Imperfect knowledge or data on the system being described.

Environment-related SPIs are organizations, initiatives or projects that work at the boundary of science, policy and society to enrich decision making, shape their participants’ and audiences’ understandings of problems, and so produce outcomes regarding decisions and behaviours.

Scenarios are representations of different possible futures from a defined starting point. They are focused on highlighting or exploring drivers of change and the impacts of changes in these over a specified time frame. In doing so they enable decision-makers to anticipate potential changes and develop timely responses to these.

Representations of possible futures for one or more components of a system, particularly, in this assessment, for drivers of change in nature and nature's benefits, including alternative policy or management options.

Representations of possible futures for one or more components of a system, particularly for drivers of change in nature and nature's contributions, including alternative policy or management options.

Representations of possible futures for one or more components of a system, particularly, in this assessment, for drivers of change in nature and nature’s benefits, including alternative policy or management options. Exploratory scenarios (also known as “explorative scenarios” or “descriptive scenarios”) are scenarios that examine a range of plausible futures, based on potential trajectories of drivers - either indirect (socio-political, economic and technological factors) or direct (e.g. habitat conversion, climate change).

Quantitative or qualitative exploration of future pathways through use of scenarios.