To be clear, when people say "Saving the earth", they mean "Make sure it supports human life".
To not interpret it as such means you are missing the whole point and concern people have about this issue.
I have heard plenty of people state that they dont care about the environment, which means that they will do nothing to change their habits. Habits that in effect, harm the environment enouth to cause its destruction.
It is ignorant to think that by simply living, we are not harming the environment.
And it is ignorant to think that somehow a "Capitalistic market will save the environment, and everyone from overfishing, increased emissions causing increased heat, which causes drought, asthma, respiratory issues, and cancer."
The fact is, if we rely on money as the driving factor to fixing our worlds declining ability to support human life, we will not be around much longer. As we all know, there is money in fishing and farming when supply is reduced and demand is increased, and there is money in the medical industry with dealing with these issues instead of fixing the cause.