601 - 1000 as it is ideal for plant growth and thus for FOOD. It allows plants to grow in less ideal conditions such as cooler or drier than normal. There are already food riots due to shortages and the population continues to increase.
The concentration of CO2 has been that high in the past and the Earth did not pass any 'tipping points'. I cannot see any downside.
Of course not for temperature since CO2 has no effect on that. I picked 1001+ because that’s good for crops. 10,000ppm would be optimal since that’s what farmers usually run in their “real greenhouses” and still humans are not affected, global temperature neither. But if anyone has a proper skill to pull up global temperature up a little bit, I’ll surely vote for that as well.
I like to grow and eat plants. Most of the animals I know eat plants or eat animals that do. I know its wrong and we shouldn't treat the plants as lesser beings and eat them but I do it anyway. Animals too.
higher from current is much better than lower...
The ideal is over 1000ppm based on the CO2 content of the atmosphere when most if not all plants came into existence. Many plants continue to increase their productivity well past 1800ppm.
Ideal for what? People (agriculture?) Plants? Staving off another ice age?
I left 601-1000 because thats the range best suited to grow agriculture. Humans are not affected by that amount, and the climate has carried far more than the 386 ppm as of now without melting everything.