Here is a quote from Pielke Sr.: «First, as can be seen from Fig. 1, A and B, ignoring data after 1996, linear trends in globally averaged 1000 — 300
hPa thickness temperature and 300 hPa over 1979 to 1996 were not significant -LSB--- 0.045 °C / decade (P = 0.55) and — 2.59 m / decade (P = 0.33) for 1000 — 300
hPa thickness temperature and 300 hPa height, respectively].