The quandary of detecting the signature ofclimate change in Antarctica

Global warming driven by human activities is expected to be accentuated in polar regions compared with the global average, an effect calledpolar amplification. Yet, for Antarctica, the amplitude of warming is still poorly constrained due to short weather observations and the largedecadal climate variability. Using a compilation of 78 ice core records, we provide a high-resolution reconstruction of temperatures over thepast 1,000 years for seven regions of Antarctica and direct evidence of Antarctic polar amplification at regional and continental scales. We alsoshow that the amplitude of both natural and forced variability is not captured by the CMIP5 and six model ensemble members, which could beexplained in part by the Southern Annular Mode. This shows that failing to consider the feedback loops causing polar amplification could lead toan underestimation of the magnitude of anthropogenic warming and its consequences in Antarctica.