Arctic sea ice decline and its ecological and economic consequences

Arctic sea ice consists of two types of ice. The first is old ice that has existed for thousands of years, since at least the last Ice Age, and the second is new ice that forms each year. The older ice is thick, while the new ice is thinner. The retreat of the Arctic sea ice is being driven by reductions in the older, thicker ice. New ice typically thaws each summer anyway, so the reduction in summer ice cover is strongly related to the thawing of the older, thicker sea ice.

Climate change is responsible for this melting. The Arctic climate is warming at a faster rate than the overall global climate. More heat is being brought into the Arctic through the atmosphere and ocean currents, so the increase in heat globally is a contributing factor. Corell (2013) also explains that there are several local factors contributing to the rapid decline of this ice. The more ice melts, the more ice will melt, because this is a feedback loop. Ice reflects light, while dark surface absorbs it. Thus, the more ice melts, the more dark surface exists to absorb solar energy and the warmer the region gets locally. Furthermore, dark carbon deposited in the Arctic also attracts more solar radiation, contributing further to the accelerated warming of the Arctic climate. Water evaporation is also a greenhouse gas, so the more water evaporates, it will also accelerate warming at the local level.

2.

Climate change in the Arctic is having a significant effect on its natural systems. Changes in the climate mean changes in the seasons, which affect the delicate balance of life in that environment. Misalignment of timing between reproduction and the emergence of food can threaten many species.

Another impact is that southern species are beginning to move into Arctic habitats, the red fox for example displacing the Arctic fox. Animals are also being forced to change their habits, including timing of mating and animals that depend on the ice are affected significantly, including walruses and narwhals. Many species are being forced to rapidly shift their habits with regards to feeding and reproduction. There is evidence that this is occurring, but nature is not able to move as quickly as the climate is changing, which puts species at risk.

3.

The authors understand the "rush for Arctic resources" as the quest for access to oil and gas in the Arctic, much of which will become more available as pack ice retreats and the climate becomes less extreme. This is ironic, of course, since fossil fuels are at the heart of the problem, and exploiting them further will only accelerate climate change more.