The polar regions are experiencing rapid climate change with noticeable impacts on terrestrial ecosystems, and further increases in temperature and precipitation are expected throughout the Arctic and the Antarctic. Geographic and environmental differences suggest that climate change responses will differ between the Arctic and Antarctic. Changes in belowground communities will likely be driven mainly by vegetation type changes in the Arctic, while belowground communities in Antarctica will respond to climate amelioration directly and indirectly through changes in microbial community composition and activity, and the development of, and/or changes in, plant communities. However, most climate change models also predict an increase in the frequency of extreme events, i.e. heat waves, large precipitation events, drought etc., in both the Arctic and the Antarctic. As I will show, extreme events can have disproportionally large impacts on belowground communities despite their short timeframe by exposing biota, vegetation and ecosystems to extreme climatic conditions. Such events may therefore be of greater importance than long-term gradual changes in climate particularly in the polar regions where soil communities are considered simple with most organisms existing at the edge of their physiological capabilities.