A new reconstruction for SE Greenland (1796-2013) shows temperatures have risen and fallen without any hockey-stick-like trajectories for the last 200+ years. Temperatures were warmer than today in the 1920s and 1940s and even briefly during the 1800s.
If rising CO2 concentrations are a driver of Arctic warming, the 19th and 20th centuries should presumably have been much colder than today.
A new study (Wangner et al., 2020) instead finds there were:
(a) warming and cooling episodes of multiple degrees per decade throughout the last ~215 years in southeast Greenland;
(b) decadal periods in the 1800s were occasionally warmer than 2013; and
(c) more sustained warming in the 1920s and 1940s than during the 21st century.