Range of sea ice extent models spread for northern hemisphere

CMIP5 multi-model simulated time series from 1950 to 2100 for  Northern Hemisphere September sea ice extent (5-year running mean). Time series of projections and a measure of uncertainty (shading) are shown for scenarios RCP2.6 (blue) and RCP8.5 (red). Black (grey shading) is the modelled historical evolution using historical reconstructed forcings. The dashed line represents nearly ice-free conditions (i.e., when sea ice extent is less than one million km2 for at least five consecutive years).