Umair, a change is needed for sure, but I actually believe it is already happening.
I think you are right to say massive investment is needed, but trying to put a finite value on it seems to me like a constraint imposed by a limitation in the way we’ve thought about money and wealth to date.
(Understandable, as you are an economist, so have probably been subject of much conditioning, evidenced by your ability to make any sense of the triple bottom line reference you’ve quoted!)
The mistake is to believe there is actual wealth tied up in money and assets.
That is why you believe the problem is bounded, thus there is a bounded amount needed to fix it.
If we talked in terms of nature, that is a little like saying OK, we have a problem due to scarcifying the sunlight for a while. We have X amount of sunlight which is tied up by certain individuals and organisations, so we need them to release X amount to fix the problem.
But that wouldn’t fix the fact that we’d been scarcifying the sunlight, so the problem would inevitably come around again.
All we really need to do, is learn how to switch back on the sunlight again, and all problems are instantly fixed.
It is the human construct of believing wealth is something to be possessed that we all need to get rid of, to undo artificial scarcification.
Fixing that is simple, when the effect of switching back on the sunlight is seen.
The key is in free money, as in my featured story.