[CedarDave]

I've looked at that second figure in the link several times and the solid line does produce a slight "hockey-stick" appearance. However, when you imagine the figure without the line you don't see a trend up or down. My question is how the solid line is produced. Two, three, four or more years running average as it appears to lag the data by a couple of years.

[Behemoth the Cat]

"My question is how the solid line is produced."

The solid line probably represents averages over some cumulative periods. I bet they carefully adjusted the lengths of these periods to come up with convincing "heating trend" in recent years.

[ElectricStrawberry]

....but but but if you look from ONLY about 1980 to ONLY about 1998.......there is clearly a significant upwards trend......muaaaaahahahahahahaha....

Why this has the keyword of “evolution” is unclear...