Summer Arctic sea ice extent is shrinking by 13% per decade and the sea ice cover continues to be younger and thinner. The declines in sea ice thickness and extent, along with changes in the timing of ice melt, are putting animals that are particularly ice-dependent—such as narwhals, polar bears and walrus—at risk.

If we can hold the global temperature increase to 1.5°C, the Arctic may retain some summer sea ice—a critical component of its marine ecosystems. But if the increase is greater than 1.5°C, we will lose Arctic summer ice within decades. 

The rapidly diminishing Arctic sea ice is accelerating warming for the entire Earth. Sea ice reflectivity helps regulate the amount of sunlight that enters the Arctic region—and in turn, the area’s temperatures. As more sea ice disappears, the underlying ocean surface is exposed. This much darker ocean surface absorbs sunlight instead of reflecting it, allowing much more heat to enter the Arctic system. It is a vicious circle: less sea ice means more open ocean, more heat absorption and more climate change, not just within the region but also beyond.

While Arctic glaciers and ice caps represent only 25 per cent of the world’s land ice area, meltwater from these sources accounts for 35 per cent of the current global sea-level rise.

The Greenland Ice Sheet is the world’s second-largest repository of freshwater. As it melts into the ocean and raises sea levels, the effects will be felt around the world. Under a business-as-usual scenario, Greenland alone could lead to a sea level rise of as much as 33 centimetres—this century alone. By 2200, it could be a metre or more.

Climate change has been identified as the major culprit behind the wildfires we are witnessing in the Arctic. The number and frequency of extreme forest and tundra wildfires, notably in Alaska and Siberia, are increasing as the Arctic warms, leading to evacuations, loss of economic activity, and negative health effects.

Wildfires are a negative feedback loop for climate change because they release greenhouse gases. They threaten ecologically valuable habitats for species like caribou and salmon. Declines in these species, in turn, threaten food security, infrastructure, health and cultural identities for people living in the Arctic.

Permafrost, covering a quarter of northern hemisphere landmasses and extending to ocean floors, comprises permanently frozen ground layers. It serves as a crucial carbon reservoir, stabilizing terrain, averting erosion, and supporting infrastructure. Vital for Arctic wildlife like migrating reindeer, it prevents them from sinking in wetlands, especially during spring migrations. However, permafrost temperatures have soared to unprecedented levels in the last three decades. Thawing and degradation pose risks to structures such as buildings, pipelines, and airstrips, potentially leading to instability. By 2050, up to half of Arctic infrastructure could face damage due to permafrost deterioration.

Arctic coastlines have some of the highest rates of erosion on Earth. The combined impacts of long-term warming (higher water temperatures, longer ice-free seasons, continuing permafrost thaw) and extreme events (such as storm-driven waves) are driving the increase.

Up to five metres of coastline are disappearing every year in some areas of Alaska. With little or no sea ice to buffer shorelines, storm surges are extending their reach several kilometres inland, flooding communities, killing wetlands and accelerating the thawing of permafrost. Along with damage to property, this is causing the irreversible loss of livelihoods and cultural heritage.