Climate Change and Arctic Feedback

Climate change is an overarching phenomenon that is affecting all parts of the world, as well as being affected by all parts of the world. The aspect of one change causing subsequent changes is called ‘feedback’. Feedback is called ‘positive’ when the subsequent effect enhances the initial cause, similar to how running on a hot day makes you feel even hotter. Feedback is called ‘negative’ when the secondary effect works against the initial effect, like how it requires more effort to juice an orange that is already half juiced, than one that is has not been juiced at all. These feedbacks on the climatologic scale can play a pivotal role in how climate change can worsen over time. This phenomenon can most easily be tracked within the Arctic Circle, so we will focus there for this piece.  

            The feedback mechanisms over the land and the oceans differ, so we will discuss over land factors now and oceanic mechanism later on. The initial mechanism is a generally warming atmosphere due to the effect of increased levels of greenhouse gases. Most land within the Arctic Circle is covered in a layer of permafrost with varying duration and thickness. Permafrost is when the ground is frozen solid form most of the, if not the entire, year due to the cold temperatures. As the atmosphere starts to warm, so too does the ground underneath of it. This will gradually thin and deplete the permafrost over time. The main cause for concern here is that there is significant amount of methane gas trapped underneath of the permafrost across a large area of the land within the Arctic Circle. This methane exists in these areas as the result of decaying biologic matter from thousands to millions of years prior. Methane is itself a powerful greenhouse gas, and would only worsen the ongoing greenhouse effect. This creates a loop of positive feedback, where the warming of the atmosphere causes permafrost to melt, which releases additional greenhouse gases into the atmosphere, causing a cyclic pattern that will continue to worsen autonomously. Additionally, and contrary to what some will state, there isn’t much benefit to be gained from the no longer frozen land. The land will be unstable, so buildings will not be able to be constructed on it, and it will be very poor for agriculture, so large scale farming cold not occur.

            Feedback mechanisms also are present over the oceans within the Arctic Circle. Most of the oceans within the Arctic Circle are covered in ice permanently or semi-permanently for most of the year. The warming of the atmosphere is causing more of the permanent ice to become seasonal, and the edges of the existing seasonal ice to disappear. This causes a positive feedback due to the decreasing albedo of this region. Albedo is a measure of the reflectivity of a surface, and decreasing the albedo of a surface proportionally increases its ability to absorb light and heat. This follows that: warmer atmosphere melts some of the ice, the exposed ocean is less reflective than the ice and can absorb more heat, thus warming the neighboring ice more, and creating a circular pattern of melting arctic ice sheets. In theory, the increase in ocean surface could also create a negative feedback because some atmospheric carbon dioxide can be absorbed into the newly exposed ocean. However, this effect would be incredibly minute compared to the rate of absorptive warming, let alone the rate with which new carbon dioxide is entering the atmosphere through the burning of fossil fuels and other human causes. A secondary effect of the melting of the existing sea ice is the collapse of the local ecosystems in this area, as the habitat for arctic animals melts away into nothing.

            So, to sum up, climate change is affecting the entire world. There are many factors that influence the effects that climate change will have on an area, as well as the intensity of those changes. As demonstrated by our selected area of study, many of the aspects of climate change are part of a feedback loop of some kind. The majority of are a positive feedback that worsens the existing patterns of change. Some negative feedback loops that work against the existing patters do show up, but are unfortunately rendered inconsequential at the larger scale. This could however be used for our benefit as well. These loops would work in reverse, meaning that if we could lessen the initial causes, the lops would help to create a trend where less change could happen, which is the ideal scenario for successful continuous inhabitation of the Earth.