What a dangerous idea.
Besides, it's not the issue of absolute population: it's emissions per capita that we should care about.
We could be doing a lot better per capita in these dimensions: - plastics & packaging, - energy use, - military pollution, - advertising & marketing bullshit, - bullshit products manufacturing
There's a lot of inefficiency in current economy, which is supported by industrial consent manufacturing.
We don't get a free pass to emit more as our population increases. The atmosphere doesn't magically adjust. The effect of emissions on the climate is invariant of our population, and we need to act accordingly.
That being said yes we need to drastically reduce the population, but that really can't be done and will have to happen itself by appealing to the vanity and self-interest of people once they are integrated into the logic of the modern religion. Though as I said that still will not solve the problem. But hey at least there will be fewer people.
And if you think that this is not true, that development leads to declining population then why are all the rich countries still growing through immigration? Their local population has stopped reproducing due to logic of the markets and self-interest and narcissism sure but they continue to grow and if they stop growing everyone talks of it as if it's a horrible thing.
This cannot go on forever if we don't start putting a maximum cap on our population, then we are heading for a disaster and the Earth itself is going to start doing what we have refused to do so so far.
Except that the reduction of our population will happen through heatwaves, pandemics, droughts...
Then what?