Why is Arctic sea ice so important?
Arctic sea ice keeps the polar regions cool and helps moderate global climate. Sea ice has a bright surface, so 80 percent of the sunlight that strikes it is reflected back into space. As sea ice melts in the summer, it exposes the dark ocean surface. Instead of reflecting 80 percent of the sunlight, the ocean absorbs 90 percent of the sunlight. The oceans heat up, and Arctic temperatures rise further. A small temperature increase at the poles leads to still greater warming over time, making the poles the most sensitive regions to climate change on Earth. According to scientific measurements, both the thickness and summer sea ice extent in the Arctic have shown a dramatic decline over the past thirty years. This is consisistent with observations of a warming Arctic. The loss of sea ice also has the potential to accelerate global warming trends and to change climate patterns. For more information about the importance of sea ice, including its importance for global ocean circulation, peo
