The Greenland end-of-melt-season snowline should presumably be exhibiting a trend consistent with consequential Greenland ice sheet melt, especially an increase in the bare ice area. Yet, consistent with the recent non-warming trend for Greenland, there has been no statistically significant linear trend in these key climate change metrics.
The Polar Portal Arctic tracking website includes a snowline metric that “integrates the competing effects of melt (increasing snowline elevation) and snow accumulation (decreasing snowline elevation)” for the Greenland ice sheet. The overseers of these observational data acknowledge that snowline “provides a key holistic variable indicating climate change”.
Scientists have needed to admit that neither the end-of-melt-season snowline nor observations of bare ice extent “exhibits a statistically significant trend over the entire study period [2001-2017]” (Ryan et al., 2019).
Image Source: Polar Portal and Ryan et al., 2019
The lack of any statistically significant trends in snowline or bare ice area is consistent with the flat to declining temperature trends for Greenland this century, or from 2001-2019.
Hanna and colleagues (2021) document “a cooling pattern over the last 6-7 years” for Greenland that has offset or overwhelmed any warming pattern from 2001-2012. Notice that the clear majority of temperature stations have been cooling in all 4 seasons since 2001.
Image Source: Hanna et al., 2021
Perhaps Greenland will cooperate with the anthropogenic global warming narrative at some point in the future.