If we are to continue life on earth, we must look at earth as a life form and calculate how much we are contaminating earth’s natural water and oxygen replenishment systems.
Everything else comes next - the sooner we realize this the more chances we have to minimize the long-term damage to the planet.
Humans use of water and oxygen with reckless abandon over the last 1000 years has come at a cost. We are now starting to understand the receiving water environments have already reached crisis points and in many cases, of no return with the damage already permanent.
In 1830 the global population reached 1 billion people, in 1930 it reached 2 billion people - with this significant population increase, manmade contamination of rainfall was now starting to make an impact. Fast forward nearly 100 years later we now have 8.2 billion people.