Through easy to understand illustrations, Alexandre Magnin explains why global atmospheric temperature increases are due to increased concentrations of carbon dioxide and methane (aka human made). He based this on the Vostok ice core research, published in 1999, as well as more recent research published by the European Project for Ice Coring in Antarctica (EPICA) and the Intergovernmental Panel on Climate Change (IPCC) report that was published in 2013. Check it out!
https://sustainabilityillustrated.com/en/portfolio/is-climate-change-human-made-vostok-ice-core/