The problem of people using straight line ‘trends’ of any climate time series is that I think that Nyquist might have uttered the rather dry observation
“The width of the data capture window available does not support the bandwidth required to get to that frequency. You can’t draw a straight ‘trend’ line on a time series graph as that implies an infinite lower bandwidth which you do not have in that data”.
Nyquist has two limits. One at the top end everybody quotes. But there is also the lower limit as well. I am just pointing out that he said that also.
Straight ‘trend’ lines on time series graphs are propaganda (or fool yourself anyway) at best. Not science. IMHO. He might have agreed.
Seems like others agree