Consequences of Arctic Sea Ice Melt

Although a perennially ice free Arctic Ocean may be decades away, an ice free summer is a much more pressing reality. Fundamentally, this means the temperature increase is so that it melts all of the seasonal ice annually and consequently starts to erode down the solid multi-year ice. This point will almost undeniably occur within our lifetime and maybe sooner than we think. Basic extrapolation of sea ice volume data places it in roughly 2020. Given, the simplicity of this prediction it would be foolish to take it as truth, however, Overland and Wang (2007, 2009, 2012) used climate model projections as well as encompassing several more severe drops such as 2007 and 2012. Climate models using CMIP5 are often cited as being too conservative (Kumar et al, 2013), yet they still predict a sea ice free summer by around 2040. Considering this is considered a conservative estimate it may well be closer towards the models that assimilate rapid changes which predict around 2030.

2030? Is that our best guess? Holland et al (2006) would agree. Despite it being 11 years later the paper predicts several rapid ice extent retreats, each one 4 times larger than observed decline. Incidentally this would be an underestimate, both the 2007 and 2012 minima were far lower than was predicted (NSIDC), this makes his estimate of 2040 using 7 different climate models arguable conservative.

Figure 1: Sea Ice extent in September 2015. The gold line represents the 1981-2010 average September extent. Credit: NASA

So what if we have ice-free summers by 2030?

Departing from the physical and environmental consequences let’s look at the anthropogenic impacts. By this, I refer to both the Inuit populations whose livelihoods rely on the formation of the sea ice, but also to the market and how this new scenario we have created can be exploited.

Tourism to the region has already increased over the past decades with more of the Arctic ocean becoming more and more accessible to cruise ships for longer times within the summer. Adventure Canada have run tours to the Arctic for 25 years and operate as sustainably as possible, including engaging with locals through employment and meetings to not impose on their culture however a new wave of tourist industries may not carry out the same procedures. Referring back to environmentalism, the burning of diesel produces non-organic black carbon, as opposed to that produced by forest fires which can bring about cooling this form does the opposite. Shipping contributed to 7-9% of global black carbon (http://www.theicct.org/blogs/staff/black-carbon-emissions-shipping-fact-checking-conventional-wisdom) and given that it accounts for 90% of international trade (International Chamber of Shipping, 2014) it is an acceptable level. However, in the Arctic unfortunately the same cannot be said. Localised production of black carbon by increasing levels of cruise ships and oil seeking ships, read on, causes a layer of black to form on top of the remaining ice within the area. Thinking back to the albedo effect, this new dark surface causes increased shortwave radiation absorption directly into the ice, promoting melt.

Despite Shell announcing in September 2015 that it would be abandoning exploration in Alaska for the foreseeable future, it is not likely to last for long, certainly not for the rest of the field. Unfortunately, with dwindling land and ocean supplies of oil the Arctic is the next suspected area for exploration. Despite difficulties faced by Kulluk in 2012, ran aground after losing its tow in the heavy weather, there is almost certainty that companies will move back in the coming summers as it becomes safer and safer to explore during the summer months. This brings with it the dangers of oil spills among other incidents, all of which would be catastrophic in such an environment.

Figure 2: The Kulluk Oil Drill Barge run aground in Northern Canada after it became detached from its tow line in stormy seas. Credit: United States Coastguard

A quick cultural run down.

The loss of Arctic Sea Ice and it's subsequent effects on wildlife habitats, numbers, and migratory behaviour; the transport routes needed to subsist; the duration of seasons; and the condition of fisheries and wild marine life are vital to the survival of native populations. The Arctic Resilience Report released in 2016 states that the mobility of the populations and their animals is already greatly reduced therefore causing a massive change in the ecosystem structure within the polar regions. The increased tourism may also reduce the sense of place felt by natives as well as the effects of a dominant and disruptive body of tourists entering their social system.