Global warming hiatus: An update and synthesis
Prof. Shang-Ping Xie
University of California San Diego, USA
Since the late 19th century, global-mean surface temperature (GMST) has risen in staircase-like stages due to contributions from both radiative forcing and internal variability. Recent studies show that tropical Pacific variability, specifically the La Nina-like cooling, caused the recent hiatus of global surface warming during 1998-2013. Likewise, tropical Pacific variability intensified the early 20th century warming during a time when the radiative forcing was much weaker than at present. The positive Atlantic Multidecadal Oscillation contributed to the enhanced warming over Arctic land that characterized the early 20th century warming. The talk reviews recent advances in this research topic. An important legacy of hiatus research is a tighter connection between the climate variability and change communities, with an increased recognition of the importance of internal variability in climate change and vice versa.