Module VIII blog

Essential Question:

How are Arctic sea-ice, climate and culture all connected?

Arctic sea ice plays an important role in both Earth's temperature regulation and in the cultures of circumpolar peoples. From a climate standpoint, less polar ice (see photo below, NASA) means that the amount of light reflected back into space is reduced, which leads to increased temperatures on Earth, which increases the amount of polar ice that melts, and so on in a positive feedback loop. From a cultural standpoint, less ice could mean a serious shortage of food gained by traditional means, the loss of transportation routes, and potentially a total loss of culture.
Sea water freezes later than fresh water due to the different freezing points of saltwater vs. fresh water. Also, even when salt water does freeze, it tends to push the salt out before the ice forms. This means that the water beneath sea ice is even saltier than usual, and therefore denser. In simple terms, the dense salty water sinks, warmer equatorial water flows north into the space left by the sinking polar water, and the end result is thermohaline circulation in the oceans (as discussed in Module V). As less polar ice forms, it follows that less of this dense salt water will be produced, and that these deep ocean currents will be weakened, which will alter the climate.

A further consequence of less persistent sea ice is that as ice ages, more and more of the salt trickles out of it, and eventually it can be used for drinking water. Alaska Native peoples typically will use this "multi-year" ice as a source of clean water. Less ice persisting from year to year means less clean drinking water. Also, changing ice conditions increase the danger for hunters. There has been an increase in the number of accidents on the ice, nearly all related to thinner, mushier ice. (Broken sea ice photo, NSIDC)

Both western scientists and Native peoples are concerned about the effects of climate change, and they are beginning to work together for the benefit of all, both in the Arctic and elsewhere. Alaska Natives and other circumpolar people who have been living close to the sea-ice have minute and long-term observations on sea-ice in their local areas. Western scientists have access to data from many regions as well as tools like computerized climate models. As the video with Steve MacLean illustrated, it's also a benefit for Alaska Native people to be trained scientists. Ideally, they can use both traditional Native knowledge and western scientific knowledge to make positive changes in the places they love.