A sealing system for a bearing compartment comprising: a runner configured to extend circumferentially around a rotating component, wherein the runner is formed of a material with low radial thermal growth, wherein the runner is configured to fit to the rotating component with at least a portion of an inward facing surface of the runner meeting with the rotating component, and the runner includes an outer surface configured to provide passive cooling for the runner in the bearing compartment; and a static structure located radially outboard of the runner, the static structure including: a retainer assembly; a first carbon seal element disposed in the retainer assembly on an oil side of the retainer assembly and radially outboard of the runner, the first carbon seal element configured for rubbing contact with the runner to reduce oil leakage from the bearing compartment; characterised in that the static structure further comprises: a second carbon seal element disposed in the retainer assembly on an air side of the retainer assembly and radially outboard of the runner, the second carbon seal element being a clearance seal configured for non-contact with the runner along an entire axial extent of the second carbon seal element; and one or more openings in the retainer assembly, the one or more openings configured to admit a flow of buffer air through the retainer assembly at a location radially outboard of a radial extent of the first carbon seal element and the second carbon seal element. a runner configured to extend circumferentially around a rotating component, wherein the runner is formed of a material with low radial thermal growth, wherein the runner is configured to fit to the rotating component with at least a portion of an inward facing surface of the runner meeting with the rotating component, and the runner includes an outer surface configured to provide passive cooling for the runner in the bearing compartment; and a static structure located radially outboard of the runner, the static structure including: a retainer assembly; a first carbon seal element disposed in the retainer assembly on an oil side of the retainer assembly and radially outboard of the runner, the first carbon seal element configured for rubbing contact with the runner to reduce oil leakage from the bearing compartment; characterised in that the static structure further comprises: a second carbon seal element disposed in the retainer assembly on an air side of the retainer assembly and radially outboard of the runner, the second carbon seal element being a clearance seal configured for non-contact with the runner along an entire axial extent of the second carbon seal element; and one or more openings in the retainer assembly, the one or more openings configured to admit a flow of buffer air through the retainer assembly at a location radially outboard of a radial extent of the first carbon seal element and the second carbon seal element. a retainer assembly; a first carbon seal element disposed in the retainer assembly on an oil side of the retainer assembly and radially outboard of the runner, the first carbon seal element configured for rubbing contact with the runner to reduce oil leakage from the bearing compartment; characterised in that the static structure further comprises: a second carbon seal element disposed in the retainer assembly on an air side of the retainer assembly and radially outboard of the runner, the second carbon seal element being a clearance seal configured for non-contact with the runner along an entire axial extent of the second carbon seal element; and one or more openings in the retainer assembly, the one or more openings configured to admit a flow of buffer air through the retainer assembly at a location radially outboard of a radial extent of the first carbon seal element and the second carbon seal element. a second carbon seal element disposed in the retainer assembly on an air side of the retainer assembly and radially outboard of the runner, the second carbon seal element being a clearance seal configured for non-contact with the runner along an entire axial extent of the second carbon seal element; and one or more openings in the retainer assembly, the one or more openings configured to admit a flow of buffer air through the retainer assembly at a location radially outboard of a radial extent of the first carbon seal element and the second carbon seal element.