My suspicions are always aroused when I see an IPCC (entirely political org) hockey stick, which they've now abandoned. Also look at 1. How much data 'adjustment' NASA/GISS have made to their temp records,  and strangely always to accentuate the warming narrative (cool the past, warm the present), it's all on record (mainly documented by Steve Goddard), 2. how unscientific the IPCC really are  (read Donna Laframboise's "...Delinquent Teenager..." book for a damning expose), & 3. read Muray Salby's work on the inter-relationship of temperature and CO2, in which he finds atmospheric CO2 lags temperature on all timescales. Basically,  never trust either statements from authority or from activist scientists.