I can think of many reasons not to have kids but climate change is not on the list.
Where do these people get the idea that having children will affect the climate one way or the other? What MIGHT affect the future of any additional children is the mental imbalance shown by this person believing crap like how it changes the climate. THAT could truly have an effect on any future children.
Anyone falling for the man-caused climate change scam should not have kids. It will help improve the gene pool long-term to get that stupidity/gullability gene eliminated.