Today we’re taking a look at the world’s coldest ecosystems.
Tundras are treeless ecosystems found at the far North and South of the Earth. The average temperature in the tundra is often sub-zero and rainfall is scarce, with much of the ground remaining frozen all year round (which is known as permafrost). There are 3 types of tundra: Arctic tundras, Antarctic tundras and Alpine tundras. Any vegetation is generally low-lying, with a short growing season. The harsh conditions in tundras make it difficult for life to survive, yet some species such as arctic foxes, grey wolves and polar bears, have managed to thrive in these cold, barren ecosystems. There is also another cold ecosystem known as a taiga, which is similar to a tundra but the main differences being that taigas have trees and are warmer than tundras. The Arctic and Antarctic regions would technically be classified as polar deserts (a type of cold desert), which, again, are very similar to tundras, with slight differences in temperature and precipitation. For the sake of simplicity, we’ve simply referred to all the cold ecosystems as “tundras” in this article.
Did you know that ice can provide a window into the past? Scientists have managed to figure out what the Earth’s climate was like thousands of years ago using ice from the tundra! By drilling out “ice cores”, scientists can study the composition of the ice at different depths. This has provided us with invaluable information about the Earth’s past climate, such as the composition of the air (and carbon dioxide concentration), and atmospheric temperature.
The tundras also play a surprisingly big role in climate regulation. Firstly, they are very important carbon sinks; in fact, it is estimated that there are 1500 gigatonnes of carbon frozen in permafrost - that’s twice as much carbon as the atmosphere currently contains! The ice and snow also have another important purpose. Snow is white, so it has a very high albedo - this means that it’s a very good reflector of light energy. Because of this quality, the ice sheets at the poles essentially act as a shield, reflecting sunlight away from the Earth and back out into space, helping to keep the planet cool.
With its extreme conditions, it’s easy to see why the tundra ecosystem is so fragile. This also makes it incredibly susceptible to climate change. Even the slightest increase in temperature can put the incredibly sensitive food web greatly at risk of tipping out of balance, which can have severe and lasting repercussions on the ecosystem as a whole. Furthermore, rising temperatures are also causing permafrost to melt, releasing all the greenhouse gases that had previously remained trapped underground. Drilling into the ice, especially during the extraction of fossil fuels, can release even more greenhouse gases into the air, namely carbon dioxide and methane. Tundras are also at risk due to the rising temperatures, and the melting ice caps at the poles will cause a lot more problems than just sea level rise: the decreased surface area of ice means that there’s less space for Arctic and Antarctic species, putting them at risk of extinction due to habitat loss. And, to make matters worse, the loss of ice is actually accelerating the temperature increase as less sunlight is being reflected away from the Earth, which is in turn accelerating the rate at which the ice is melting, causing an endless loop known as a positive feedback loop (find out more here).
Like all ecosystems, the tundra is worth protecting. We might not be able to re-freeze the tundra, but we can help halt any further melting. The only way to do this is to prevent the planet from warming any further, which means stopping global warming. Therefore, the best thing we can do is to reduce our reliance on fossil fuels and transition to using clean energy as soon as possible. We should also ban the extraction of fossil fuels in the tundra to prevent releasing any greenhouse gases that are trapped underground. And, to prevent the species from going extinct, we can introduce conservation laws and captive breeding programs to help keep populations stable while the ecosystem recovers. The tundra is a valuable asset in helping to combat climate change, and we’re losing it fast; that means we also have to act quickly to save it.
Credits:
Images - Let’s Talk Science, Lindsey Nicholson
Information - DK Simply Climate Change, National Geographic, MIT
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