Human Activities
The ongoing loss of Arctic sea ice has implications for marine shipping, tourism, oil and natural gas production, Arctic residents, and international politics.
Shipping Routes
Once Europeans encountered the North and South American continents, they began seeking a shortcut between Europe and Asia. Early explorers in ships looked for navigable summer passages through the channels of the Canadian Archipelago (the Northwest Passage) or along the Siberian coast (the Northern Sea Route). Roald Admundsen successfully navigated the Northwest Passage (Figure 1) during 1903-1906. Today satellites can help monitor ice conditions along both routes along with other methods. While occasionally and for a short time in summer these passages may be relatively clear of sea ice, full-scale commercial use remains unrealized (although Russian ships have been operating along parts of the Northern Sea Route for many years) .

Declining summer sea ice opens the prospect of a more reliable summer shortcut and increased marine traffic, with implications for naval and coast guard operations. Ships operating in this area would need accurate and timely information on ice conditions and weather, accurate maps, and port facilities. A 2013 study by Laurence C. Smith and Scott R. Stephenson at UCLA suggests that northern routes may be reliably open on a seasonal basis by mid century. Figure 2 shows a satellite image of the Parry Channel, part of the Northwest Passage, in August 2012. At the time of year this image was acquired, sea ice was approaching its annual minimum extent, and 2012 saw a record low year compared to the satellite record from 1979 to 2011.

References
Laurence C. Smith, Laurence C., and Scott R. Stephenson. 2013. New Trans-Arctic shipping routes navigable by midcentury. PNAS, March 4, 2013, doi:10.1073/pnas.1214212110.
Oil and Natural Gas Production
Reduced sea ice extent in summer will provide more favorable condition for offshore drilling of oil and natural gas resources under the Arctic Ocean. Several major companies are actively exploring how much oil and natural gas is actually available and the costs of extracting it. Key issues include the rate of sea ice decline over the next several decades and oil and natural gas prices on the global market.

Reference
Industry and ice. October 3, 2012. Icelights: Your burning questions about ice and climate. Boulder, CO: National Snow and Ice Data Center.
Thawing Permafrost
Much of the Arctic land area is underlain by permafrost – perennially frozen ground. Houses, railways, roads, runways and other infrastructure built atop permafrost will remain stable as long as the permafrost does not thaw. However, permafrost is already thawing in parts of the Arctic, locally with severe impacts on infrastructure, and this process is expected to continue as the Arctic warms.