According to IPCC's own chart there was a period of slight warming from about 1890 to 1940, followed by a flat stretch till the 1970's then a return to slight warming from then to the present. Even the last century's pattern thus makes no sense if one assumes human causation. In all probablility these micro-mini spells including the warming of the last 30-40 years are simply random variation--noise.
This would be lost on the IPCC of course since almost all of them are hired guns and scientifically illiterate government functionaries, while almost none of them are climatologists.