Yes, that. But also that these different externalities will have different responses to reduction at scale, which also impacts how effective action on a more "personal" level really is.
For example the OP was talking about plastic. A 2% reduction in plastic waste has a clear benefit, because any amount of plastic reduction is a bonus. However it is not clear that a 5% reduction in CO2 emissions due to Americans driving their cars less will have any meaningful difference when it comes to climate change.
You are right. Though for CO2 that simplification comes pretty close to true.
Could you say more?
Are you talking about comparing CO2 to N2O to CH4 to fluorocarbons, for example?
Yes, that. But also that these different externalities will have different responses to reduction at scale, which also impacts how effective action on a more "personal" level really is.
For example the OP was talking about plastic. A 2% reduction in plastic waste has a clear benefit, because any amount of plastic reduction is a bonus. However it is not clear that a 5% reduction in CO2 emissions due to Americans driving their cars less will have any meaningful difference when it comes to climate change.