Much of the research in the natural sciences currently undertaken has to do with the overall theme of climate change.
- To what extent is climate change due to natural vs man-made causes?
- What parameters, processes and interactions are needed to understand and predict future climate change?
- What are the likely impacts of climate change?
While climate change affect everyone globally, the arctic is a unique place for researching the theme for several reasons:
- In a place where ice and snow is everywhere, the effect of climate change is obvious and easy to measure. In less than 40 years, the arctic has lost about 40% of its ice coverage.
- A little bit of warming can have larger effects through positive feedback loops. Ice and snow usually reflect 80% of the radiation from the sun but as sea ice melts, water, which reflects less radiation, is exposed. The retained heat contributes to more melting ice. Thinning ice means smaller chunks break off more easily and these smaller chunks can easily be moved by wind. When wind blows through, small chunks are sea ice are more easily moved aside to expose larger connected areas of water, which absorbs more heat. On land, melting permafrost (an area of soil under the snow that is usually frozen throughout the year) releases methane gas, which along with carbon dioxide, traps heat and contributes to warming.
As a result of these factors, the arctic is warming at 2-3 times the rate of the rest of the world. It’s no wonder that year after year, record high temperatures are being reported in the middle of the arctic winter. 2018 was no exception.
Arctic warming has been attributed to disturbances in the jet stream, a column of air that runs east-west in the upper atmosphere. Disturbances in the jet stream allow warm air to move northward and cool air to move southward, accounting for unusual weather patterns. As a result, global warming can be experienced simultaneously as record snowfalls in some parts of the country and as an extended summer in other parts.
Faces of Climate Change
To many animals resident to the Arctic, changes in ice cover means, directly or indirectly, changing the way they hunt, feed, or reproduce. Saimaa Ringed Seals are on the endangered species list. They usually build their nests in the snow on top of frozen lakes. The snow bank provides shelter from the elements and predators from the fledgling young, to give them a better chance at survival early on. As winters become warmer, snow cover at op bare ice is reduced, making it more difficult for them for build their nests.
Polar bears and walruses have adapted to life on the sea ice and spend much of their lives on the ice. These predators rely on sea ice to reach areas where they are able hunt for food. As sea ice becomes thinner and more fragmented, these animals become trapped in a more limited range and unable to feed themselves, leading to starvation and declining populations.
Reindeer and caribou typically forage off the land. As the weather becomes warmer, the vegetation that typically grows in the areas where these animals roam are changing. Access to food is also hampered by ice formation where snow usually forms. As the Arctic warms and becomes less forbidding, human activity is also spreading to previously “uninhabitable” areas. Human activity and developing industries may further limit the range of these migratory animals and their access to living off the land.
Narwhals, belugas, and bowhead whales rely on disappearing sea ice to hide from predators. Decreasing sea ice have taken away a barrier that previously prevented ships from reaching northern waters. With increase in shipping traffic, whales are susceptible to collisions, water pollution, and risks of accidents like oil spills. As social animals, whales rely on unique calls to navigate, mate, and take care of their young, These intricate patterns of communication are increasingly disrupted by human-made noise. These species, whose numbers at one time were brought down by over-hunting, are now facing an even bigger threat from climate change.
Arctic foxes have adapted to survive well in extreme and harsh environment of the circumpolar north. As climate change lessens the extremes of living in the Arctic, other species such as the red foxes are extending their ranges northward. Increased competition for food and living space from opportunistic southern species have led to a decline in arctic fox populations. Similarly affected are animals like the tundra vole and lemmings, which have specialized to living in a land that is becoming more welcoming to more competitive southern species.
A spider fights back
The Wolf Spider is an abundant predator that populates the Arctic tundra. that mainly preys on Springtails. This predator prey relationship is an amazing example of how predator-prey relationships can adapt to climate change.
Researchers placed different numbers of Wolf Spiders in a series of enclosed outdoor plots. Some of the plots were heated by 2 degrees to simulate conditions of global warming. In natural temperatures, higher number of spiders and lower numbers of Springtails were found compared to warmed plots. In the warmed plots, Wolf spiders competed more aggressively among themselves, even to the point of eating one another!
This in-group fighting leaves a more abundant number of Springtails and that is good news for a warming planet because Springtails feed on fungi that release greenhouse gases like carbon dioxide and methane when they (the fungi) feed on decomposing animals and plants.
Warmer temperature = More Wolf Spider in-fighting = More Springtails = Less greenhouse gas emitting-fungi
Nature buffers against drastic temperature change by altering Wolf Spider predatory behaviour in response to ambient temperature. Now, that’s pretty cool, isn’t it?