Scientists give Earth’s climate its annual physical, highlighting ‘ridiculous’ ocean heating – Dispatch Times. Global sea level each year since 1993 compared to the 1993 average (dashed line). On the North Slope of Alaska, record high temperatures at 20-meter depth were measured at four of five permafrost observatories. The eight lowest minimum sea ice extents during this period have occurred in the last eight years. The Antarctic maximum sea ice extent reached a record high of 7.78 million square miles on September 20.