The greenhouse that I built in preschool agrees as well.
I don't think anybody disagrees that more CO2 means more plant growth. Please see the edit for why emphasizing this elementary fact is harmful (and worthy of suspiscion when coming from CSIRO).
https://climate.nasa.gov/news/2436/co2-is-making-earth-green...
https://www.co2meter.com/blogs/news/41003521-co2-calculator-...
https://co2factor.blogspot.com/2012/04/athletic-advantage-of...