I'm afraid there isn't time for mitigation for a couple of reasons.
One reason is that the damage was already done some time ago. So much damage happened to Earth's ecosystems that it would take hundreds of years of evolution before a healthy ecosystem could even begin to form.
But the real problem is:
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There are way too many humans inhabiting Earth.
Since birth control never caught on, Mother Nature is going to use her cure: a massive die-off of humans.
This is why it's called the 6th Global Extinction Event.
I've run calculations over the past decade of how many people need to die to reduce the stresses on Earth's resources.
A minor change that would make a difference is if out of every 100 people, 99 died.
A more complete remedy would be to gather all humanity in groups of 1,000 each (32 x 32 people on a square grid). Then (ahem), kill 999 of them. That would represent a sustainable level of human population worldwide.
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See, nobody in his or her right mind would volunteer to do the "thinning." This is why we'll let Ma Nature do the hard part.
But it will be too late.
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Look up. Can you see the future coming at you? Hints: California burns, the Mediterranean churns and swirls, tornadoes and frosts and fish raining down in Texas, Bangladesh being still Bangladesh--a preview for all of us.
The oncoming extreme weather and climate is much like a huge asteroid coming dead-center on a path to hit Earth on the equator.
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Luckily we each die only once in our lives. That has never changed. I take huge solace in that reality. There are ways of mourning your own death before it happens, and part of how I do that is that I write gloomy-sounding stories like this one.
Because some day I will take my last breath, and I hope I can smile and chuckle to myself about a life well-lived and a death fairly free of fear.
... Fred Ermlich, 1953-...