From 1955 to 1979, the extent of Antarctic sea ice shrank by 23% in winter and 67% in summer, then partially recovered. This is like a spring that was slowly compressed and then released: the climate of the Southern Hemisphere responded with a delay of several decades.
A one-dimensional, four-layer atmospheric model compared two sources of warming from 1955 to 2015. The contribution from greenhouse gases was 0.2 ± 0.05 K, while the albedo feedback from melting ice contributed 0.5 ± 0.1 K. The sum matches the observed temperature rise of 0.75 ± 0.1 K.
Extrapolation to 2015–2025 predicts a slowdown in warming by 33% compared to 2005–2015. This is explained by the ocean's long memory: it continues to respond to past events.
The icy spring does not uncoil all at once. The Southern Hemisphere is still catching up to changes that began half a century ago.
From 1955 to 1979, Antarctic sea ice extent shrank by 23% in winter and 67% in summer, then partially recovered. This is like a spring slowly uncoiling in the climate system.