For anyone stumbling onto this who actually wants to be educated, the science has practically unanimously agreed that climate change is mainly caused by human activity. No expert is unaware of the cycles that temporarily affect climate. They are well studied, modeled, and found to pale in comparison to human-made climate change. You can find comparisons between human and natural drivers, with sources from expert organizations and scientific studies, here and here. Funnily enough, the NOAA, which this commenter used as a source for El Niño and La Niña below, also hosts this article which literally starts by linking to a page that points out how climate change is mostly caused by humans.