But life expectancy is highest and stil increasing. Do you have any proof this trend would reverse?

That model assumes no major external factors changing.

You think life expectancy will stay the same when forests burn down, we run out of water and crops, conflicts start everywhere, cities start flooding, we get more and more storms, energy crises because we have to shut down power plants etc etc?

You're basing your read on wayyyy too simplistic a metric that compresses true life expectancy into something not accounting for most meaningful dimensions.