Click on the following to research evidence for a human impact on climate change: 

https://climate.nasa.gov/evidence/

https://www.edf.org/climate/9-ways-we-know-humans-triggered-climate-change

Click on the following to research evidence for natural cycles being the cause of climate change: 

https://www.theccc.org.uk/tackling-climate-change/the-science-of-climate-change/climate-variations-natural-and-human-factors/a-natural-climate-cycle/

https://www.fs.usda.gov/ccrc/climate-basics/climate-primer/natural-climate-cycles