All of it is caused by humans. We are otherwise in a cooling period.
Natural archives generally show that Earth's average temperature roughly 6,000 years ago was warmer by about 0.7 °C (1.3 °F) compared with the 19th century median, and then cooled gradually until the Industrial Revolution. We found that most evidence points to this result.
https://www.sciencealert.com/before-human-made-climate-change-was-earth-actually-in-a-cooling-phase