The world's tundra habitats contain highly specialised animals and plants that live nowhere else, including iconic animals such as the polar bear and the Arctic fox. Several major threats to these habitats exist, all caused by human activities.
Lichens, which each consist of two organisms, a fungus and an alga or bacterium, living in a symbiotic relationship, are highly sensitive to air pollution. In fact the growth of lichens on trees has long been used as a rough gauge of air pollution in temperate regions. The lichens in the tundra are an important food source for a range of animals, including Arctic hares, musk oxen, lemmings and reindeer. Anything that adversely affects lichens impacts the rest of the food web.
Global warming could completely destroy the tundra states National Geographic. The habitat is defined by climate and as the earth warms, the frozen earth of the tundra will melt, radically changing the habitat. The thawing itself could speed up the process, as it releases carbon trapped in organic material in the soil. Once it defrosts, decomposers such as bacteria get to work, and release further carbon dioxide into the atmosphere.
Beneath the tundra lie reserves of valuable materials, in particular fossil fuels such as oil and gas. It is impossible to extract them without some destruction of the habitat. Developments and careless mining activities are a major threat. They also fragment the habitat, a problem for animals with large territories such as polar bears.
Although the depletion of the ozone layer slowed significantly by the first decade of the 21st century according to NASA, it is still depleted over the poles, and so the tundra. The ozone layer is unlikely to start recovering until at least the middle of the 21st century. A reduced or absent ozone layer allows more UV rays through, which are dangerous to tundra vegetation and wildlife.
Oil spills seem almost inevitable wherever drilling takes place on a large scale and the results are serious. In large quantities, oil is toxic to animal and plant life. An additional problem in the tundra is that the conditions and climate make any cleanup operations difficult if not impossible. Mechanical equipment freezes and chemical dispersants may be useless, on top of the fact that such dispersants are toxic in their own right. One major oil spill in the Arctic tundra could devastate the ecosystem and cost indigenous residents their livelihoods.