This is what i was thinking ~15 years ago, but now it is painful for me to remember that i could seriously support such an idea.

Environmental friendly matters only because it is human friendly. Removing all the humans is not environmental friendly since climate change and extinctions happen a lot without humans too. Reducing number of people to half the current population is not environmental friendly since we were cutting down huge forests and driving species to extinction even before the industrial age.

The most environmental friendly thing you can do is have more than 2 children, and make sure they are well educated. There are still lots of deserts on earth that they can make into forests, we just need the science and manpower for that.

Warmer arctic region is not a problem, it gives more livable space. Higher sea level is not a problem, it gives more water to create lakes and fill aquifers in places like Sahara, Iran, and central Asia. 50 bln people on earth is not a problem, it gives more creativity and more workforce to go to Mars.

I'm with you on everything except for this part:

> Higher sea level is not a problem, it gives more water to create lakes and fill aquifers in places like Sahara, Iran, and central Asia.

Higher sea level is absolutely a problem, as it disproportionately takes away the most valuable, economically productive, and inhabited land, and causes huge refugee crises. There's no shortage of seawater. Everything you mentioned could be done now (if we had enough power for desalination anyway). Higher sea levels don't make it appreciably easier, but they sure make everything else way worse.

You are right, I should've said slowly raising. If we let it to actually rise and flood cities it would be indeed a catastrophe, but the perspective of raising sea can incentivize richer countries to invest into moving that water somewhere else.

The best (and really only) place to store that much water is in kilometer-thick ice sheets at the poles ... the melting of which is what is causing the current problems. The aquifers simply aren't close to big enough to make a dent.

If we stop having kids, then why would we bother to protect the environment?

Its a question I ask myself as I don't plan on having any. There is some instinct in me to avoid suffering of future generations. It seems to be the right thing to do. Not sure where that comes from.

I'll refer you to the opening scene from season 2, episode 6 of "Utopia": https://www.youtube.com/watch?v=rcx-nf3kH_M

To save humanity we will need some kids anyway. Who will choose who will have them?

Only if you reduce humans to simplistic 'worthless carbon-gobblers'

Having children in western democracies, where they can learn and act with large amount of freedom and information is frankly eventually much better for the planet and humanity. Compared to poorly educated children in a 3rd world country, with oppressive government, western children are much more likely to find and make solutions for energy access and technologies that allow humanity to live reasonably, potentially even off-Earth one day.