Arctic amplification is the fact that temperature rise in polar regions is large in comparison to the temperature rise in lower latitudes, may further accelerate climate warming well beyond the Arctic. The warming trend in the Arctic is almost twice as large as the global average in recent decades. The possible causes are: changes in cloud cover, increases in atmospheric water vapour, more atmospheric heat transport from lower latitudes and declining sea ice have all been suggested as contributing factors.
The loss of sea ice is one of the most cited reasons. When reflective ice melts, a darker ocean dominates; this amplifies the warming trend because the ocean surface absorbs more sun heat than the surface of snow and ice. This means decrease in sea ice reduces Earth’s albedo.
Other possible causes are thunderstorms, which are much less likely to occur in the Arctic than in tropic regions. The storms transport heat from the surface to higher levels of the atmosphere, where global wind patterns sweep it toward higher latitudes. The abundance of thunderstorms creates a near-constant flow of heat away from the tropics, a process that dampens warming near the equator and contributes to Arctic amplification.