Why is tundra globally important?

Even though it may seem too cold and barren for any life, the tundra biome is an important region that is full of different plants and animals. We need the tundra because it has a part in creating the biodiversity (the variety of species) of the Earth. Biodiversity is important because it makes Earth what it is. We depend on various living species- some provide us with food, some (such as decomposers) clean up after us, some plants (especially in the tropics) make up important medicines, etc. You'd think that the tundra is useless, but without a certain biome or living species, life would not be the same. Everything on the Earth is interconnected, so preservation of nature is so important. That is why the tundra is globally important.