  This paper aims to better understand why there was a global warming pause in
2000-2015 and why the global mean surface temperature (GMST) has risen again in
recent years. We present and statistically analyze substantial time-series
observed datasets of global lower stratospheric temperature (GLST),
troposphere-stratosphere temperature climatology, global land surface air
temperature, GMST, sea ice extent (SIE) and snow cover extent (SCE), combined
with modeled calculations of GLSTs and GMSTs. The observed and analyzed results
show that GLST/SCE has stabilized since the mid-1990s with no significant
change over the past two and a half decades. Upper stratospheric warming at
high latitudes has been observed and GMST or global land surface air
temperature has reached a plateau since the mid-2000s with the removal of
natural effects. In marked contrast, continued drastic warmings at the coasts
of polar regions (particularly Russia and Alaska) are observed and well
explained by the sea-ice-loss warming amplification mechanism. The calculated
GMSTs by the parameter-free quantum-physics warming model of halogenated
greenhouse gases (GHGs) show excellent agreement with the observed GMSTs after
the natural El Nino southern oscillation (ENSO) and volcanic effects are
removed. These results have provided strong evidence for the dominant warming
mechanism of anthropogenic halogenated GHGs. The results also call for closer
scrutiny of the assumptions made in current climate models.
