ABSTRACT
Feedbacks in the climate system are processes in which an initial atmospheric, oceanic or – as the Polar Regions are being considered here – cryospheric perturbation results in a response which either amplifies or dampens that perturbation. Climate and environmental variability is of course highly complex in any part of the world, characterized by large-scale, non-linear climate dynamics and regional feedbacks. Indeed, observed polar climate change from the instrumental record is quite different between the Arctic and Antarctic. The evidence for human influence on Antarctic temperature remains weaker than for other parts of the world, particularly as a consequence of observational uncertainties. Evidence for accelerating rates of climate feedback is therefore clearer and stronger in the Arctic than in the Antarctic. Both the Arctic and Antarctic exhibit high overall reflectivity as a result of their extensive snow and ice covers, and also as a result of their low vegetation covers; a major factor in low surface-radiation receipts.
