Dryland vegetation response to wet episode, not inherent shift in sensitivity to rainfall, behind Australia's role in 2011 global carbon sink anomaly

There is compelling new evidence that semi-arid ecosystems are playing a pivotal role in the interannual variability and greening trend of the global carbon cycle (Ahlstr€om et al., 2015). The situation is exemplified by the vast inland region of Australia, the driest inhabited continent. Using a global model, Poulter et al. (2014) inferred that Australian ecosystems contributed 57% of a record global carbon uptake anomaly in 2011 and have entered a regime of the enhanced sensitivity to rainfall since the mid-1990s. Here, we present new observation-based evidence confirming a significant role of Australian ecosystems in the 2011 carbon sink anomaly. Our results do not, however, support a shift in sensitivity of vegetation activity to rainfall.