You're the one calling me a "doomer"?
It's also 1/4 of the approximate 1,600 PPM that is optimal for a large number of plants to grow. In other words, the current levels are actually very low, compared to what the plants evolved to use.
Increased plant growth from more CO2 results in more biomass, thus more CO2 uptake, so it's a virtuous cycle and you'll be OK after all.
My post as entered is correct.
"Plants like CO2" is not a counterargument to "Increased atmoospheric CO2 will have a number of outcomes that are net negative for humanity", so I presume they're asking you to actually think about the argument being made and respond to it, not some other, made up one.
Plants growing slightly faster does not mitigate the many consequences of increased CO2.
To not even attempt to head for the lifeboats is suicide.