On living beings, most of them exhale CO2. Those who are already yelling to have fewer children (https://www.theguardian.com/environment/2017/jul/12/want-to-...) will go one step further.
Even if we accept this as a "reasonable" assumption there is another huge flaw with this statistic. The assumption is that your children will be average polluters. So no matter how much you reduce your own CO2 footprint your children will always produce more CO2 than you. Except if you teach your children to reduce their CO2 footprint by not driving a car you reduce your CO2 footprint by 25% and the CO2 footprint of your children too. Your footprint including descendants goes down from 70 tons to 52.5. A 17.5 ton decrease!
If you do everything in this chart except not having children (assuming an electric car) your CO2 footprint goes down by 38% down from 70 tons to 44 tons. Notably this requires almost no changes in lifestyle. Just switching to renewables is enough.
This chart is harmful, it only serves to make people feel helpless and not take action against climate change.
This would be true AFAICT if we somehow managed to eat without any CO2 emissions. But agriculture is a huge driver of CO2 emissions and so are logistics, electricity for cooking etc.. So while the CO2 we exhale comes from the atmosphere through plants, animals and so on, we inevitably cause a lot of CO2 emissions as a side-effect in the process.