Why is arctic ice melting

In coastal communities, thin ice also provides far less protection than thick ice from the pounding surf that accompanies fall and winter storms. Arctic sea ice declines are related to the phenomenon known as Arctic amplification : more intense warming in the Arctic than over the rest of the globe. Arctic amplification fits with current scientific understanding of Earth's climate system, and with model projections of global warming caused by greenhouse gas emissions. Multiple factors contribute to Arctic amplification, and sea ice loss is one of them.

Sea ice's white or light gray surface reflects up to 80 percent of incoming sunlight, deflecting additional energy away from the planet. With less ice present, the dark surface of ocean water absorbs considerably more sunlight energy, leading to further warming of the sea surface and overlying atmosphere, which leads to more melting of ice, which leads to more warming, and so on.

Scientists are actively studying the effects of this feedback loop to help them understand and predict how decreases in Arctic sea ice and snow cover will affect the global climate system. In the early 20th century, explorer Roald Amundsen took three years — to traverse the Northwest Passage, a route that would allow ships to travel between the Atlantic and Pacific Oceans through the western Arctic.

Although it's not yet a dependable pathway for commercial ships, the Northwest Passage has experienced relatively ice-free conditions multiple times since the turn of the 21st century, drawing tourists. Meanwhile, the Northern Sea Route along the coast of Siberia has experienced more consistent ice-free conditions in the summer, which may soon transform it into a reliable shipping route. The opening of shipping lanes across the Arctic may provide shippers with viable alternatives to traveling through the Panama Canal or around the southern tip of South America.

This new reality will have impacts not only on the environment, but also on the world economy and national security, as nations compete to gain rights to shipping lanes and newly accessible resources in the Arctic.

Loss of sea ice means lost habitat for marine mammals like polar bears, walruses, and seals, along with disruptions to the food supply of Arctic communities who depend on them. A longer ice-free season exposes Arctic communities to extreme erosion from pounding waves during winter storms. Loss of reflective sea ice and the associated ocean warming are also changing the abundance and range of commercially important high latitude fish species.

Foreign Affairs, Scott G. Accessed March 17, Accessed January 11, Accessed September 26, Intergovernmental Panel on Climate Change. We value your feedback Help us improve our content Your Email Address.

Security code. Will the Arctic be free of summer sea ice in 30 years? Images of Change. Explore a stunning gallery of before-and-after images of Earth from land and space that reveal our home planet in a state of flux. Climate Mobile Apps. Keep track of Earth's vital signs, see the planet in a state of flux and slow the pace of global warming with NASA's free mobile apps.

Climate Time Machine. Ice cover expands again each Arctic winter, but the ice is thinner than it used to be. Estimates of past sea ice extent suggest that this decline may be unprecedented in at least the past 1, years. Because sea ice is highly reflective, warming is amplified as the ice decreases and more sunshine is absorbed by the darker underlying ocean surface.

Sea ice in the Antarctic showed a slight increase in overall extent from to , although some areas, such as that to the west of the Antarctic Peninsula experienced a decrease. Short-term trends in the Southern Ocean, such as those observed, can readily occur from natural variability of the atmosphere, ocean and sea ice system. Changes in surface wind patterns around the continent contributed to the Antarctic pattern of sea ice change; ocean factors such as the addition of cool fresh water from melting ice shelves may also have played a role.

However, after , Antarctic ice extent began to decline, reaching a record low within the 40 years of satellite data in , and remaining low in the following two years. Find out about the Royal Society's latest work on energy, environment and climate. Skip to content You currently have JavaScript disabled in your web browser, please enable JavaScript to view our website as intended.

Why is Arctic sea ice decreasing while Antarctic sea ice is not?