Projections of Future Changes in Climate  Arctic Sea Ice

A warmer Northern Hemipshere will intensify melting of Arctic Sea Ice, a postive feedback loop already underway.Year-round reductions in Arctic sea ice extent are projected by the end of the 21st century. These reductions range from 43% for RCP2.6 to 94% for RCP8.5 in September and from 8% for RCP2.6 to 34% for RCP8.5 in February. Below are the projections

In the graph below, lines represent the modelled means for 1986-2005; the filled areas are for the end of the century. The CMIP5 multi-model mean is given in white colour, the projected mean sea ice extent of a subset of models that most closely reproduce the climatological mean state and 1979 to 2012 trend of the Arctic sea ice extent is given in light blue colour. Based on an assessment of the subset of models that most closely reproduce the climatological mean state and 1979 to 2012 trend of the Arctic sea ice extent, a nearly ice-free Arctic Ocean in September before mid-century is likely for RCP8.5. A projection of when the Arctic might become nearly ice- free in September cannot be made with confidence for the other scenarios.