The images above show simulations of sea ice thickness now and three decades into the future. The lightest areas represent the thickest accumulations of ice; progressively darker shades of blue indicate decreasing thickness of ice. The darkest blue represents areas of the ocean that are ice-free and gray represents land.
The top images show model simulations that match current conditions for March, when the area covered by sea ice reaches its annual maximum (left), and in September, when the area covered by sea ice reaches its annual minimum (right). Currently, sea ice up to 2.5 meters thick covers the central portion of the Arctic Ocean at the end of winter. After the melt season, as fall begins, much of the sea ice that remains is less than 1.2 meters thick (top right).
The bottom row shows projections for three decades into the future. By that time, sea ice in the Arctic Ocean will be less than 2.0 meters thick at the end of each winter (bottom left). At the end of each summer in 30 years, the projections show that sea ice in the Arctic will be very thin or totally absent.