By now, everybody knows that the Arctic summer sea ice is at an all-time low. What I only learned recently is that the extent of Antarctic ice is the greatest since satellite observation began in 1979. At the same time, it is undergoing “unprecedented collapses” like the much-discussed Larsen B collapse. Such realities hint at the complexities of the climate system.
Whereas the Arctic doesn’t have any effect on sea level, because it floats, the Antarctic rests on land. As such, changes in its ice mass do affect the depth of the world’s oceans. Antarctica is also the continent for which the least data is available, making it hard to incorporate into global climate models. As with all complex dynamic systems, there are non-linear effects to contend with. That makes it dangerous to extrapolate from present trends, especially when it comes to local conditions.
All this makes you appreciate why scientists frequently sound less certain about the details of climate change than politicians do. The harder you look at systems like the Earth’s climate, the more inter-relationships you discover, and the more puzzles there are to occupy your attention.