The polar regions, the Arctic and Antarctic, are warming fast, losing ice and their oceans are changing rapidly. The consequences of these changes are multiple and far-reaching.
Arctic surface air temperatures have increased more than twice the global average over the last two decades. Both the Arctic Ocean and Southern Ocean are warming, with the Southern Ocean being disproportionately and increasingly important in removing heat and carbon dioxide from the atmosphere. Both polar oceans are increasingly affected by carbon dioxide uptake, causing the waters to become more acidic. Arctic sea ice continues to decline, at about 13% per decade, including a 90% decline in the proportion of old thick ice over the past 30 years. If carbon dioxide emissions continue to rise, the Arctic could be ice-free in the summer by 2040. Projected permafrost melt and decrease in snow is affecting the Arctic water cycle and wildfires, with impacts on vegetation, water and food security in the region.
The rapid ice loss from the Greenland and Antarctic ice sheets during the early 21st century has increased, contributing to global sea level rise. Global average sea level has risen by 21 cm (8 inches) since 1900, endangering coastal cities and small island nations by exacerbating coastal flooding and storm surge.
Climate change in polar regions is impacting ecosystems. For example, the range of non-polar species has expanded, while the range of polar fish and ice-associated species has contracted. Increased stress on polar marine ecosystems due to climate change leads to risks for fisheries with implications for regional economies, cultures and the global supply of fish, shellfish, and Antarctic krill. Changes in polar regions will fundamentally alter climate, weather, and ecosystems globally. How big these changes and their impacts are will depend strongly on what future trajectories of carbon dioxide emissions.

How is climate change affecting polar regions and what are the consequences?