A scientific paper was recently published in the journal Atmospheric and Climate Sciences by Yanjun Mao, Jiqing Tan, Bomin Chen, Huiyi Fan. The study provides details regarding why recent global warming is primarily a result of natural causes. The authors have established three steps that support this viewpoint:
(1) Identification of periodic functions that match all of the monthly global land (GLST) surface temperature anomalies
(2) identify monthly sea surface temperature (SST) anomalies that are located within different ocean basin domains and highly correlated with the monthly GLST anomalies
(3) determine whether the dramatically increasing (or dramatically decreasing) signals coincide with GLST anomalies occurred in El Niño years (or La Niña years).
Their conclusion is that that recent global warming is primarily a result of natural causes.