by K. Richard, April 19, 2018 in NoTricksZone
The Arctic region was the largest contributor to the positive slope in global temperatures in recent decades.
Consequently, the anomalously rapid warming in the Arctic region (that occurred prior to 2005) has been weighted more heavily in recent adjustments to instrumental temperature data (Cowtan and Way, 2013; Karl et al., 2015) so as to erase the 1998-2015 hiatus and instead produce a warming trend.
Meanwhile, other scientists have been busy determining that only about 50% of the warming and sea ice losses for the Arctic region are anthropogenic, or connected to the rise in CO2 concentrations.
The rest of the warming and ice declines can be attributed to unforced natural variability.