Habitat fragmentation, reduced biodiversity and melted permafrost are a few results of human interaction with the tundra. Despite the tundra's year-round ice and sparse vegetation, it is a sensitive biome that is easily affected by global warming, industrialization and pollution.
Ozone depletion is a larger threat to the poles than it is elsewhere because ozone collects in greater abundance around these areas. As a result, ultraviolet light faces less resistance and is more harmful to living organisms of the tundra. The melting of the tundra's permafrost can also lead to increased carbon emissions, as around 1/3 of the world's carbon resides there. If enough permafrost melts, significant amounts of greenhouse gases, such as carbon dioxide and methane, will escape. This in turn can accelerate the effects of global warming.
The defining characteristics of tundra are permafrost and minor vegetation, which mostly consists of lichens, algae, mosses, shrubs and occasionally trees. Three types of tundra exist: arctic tundra, Antarctic tundra and alpine tundra. Antarctic tundra is found in parts of Antarctica and off the coasts of neighboring islands. The major difference between antarctic tundra and arctic tundra is the presence of large mammals in the latter. Alpine tundra, in contrast, is located at altitudes generally too high for tree growth and usually lacks permafrost. Alpine tundra is also not restricted to the Earth's polar regions.