Sure we could double the human population, but it all depends on where we cluster and how much of a drop in standard of living people are willing to put up with.
The current widespread destruction of the environment is directly caused by the human population and compounded by increased living standards.
If population doubled the planet would be destroyed and/or we would survive in minuscule pods and eat bland mush to survive.
This is not the same as Malthus' thesis. We are producing enough food and we would probably still do. The issue is the cost in terms of environmental destruction and quality of life.
> current widespread destruction of the environment
Have a look at the early industrial period or even the 1970s, and then have a look out the window again. There's a bit of a [citation needed] on that claim.
(just this week, for example, there was a study that showed that a major contributor to the increase in the severity of the Atlantic hurricane season in the last decade has been the great reduction in atmospheric pollution)
Where’s double of the food (and shipping thereof) coming from? At the moment, various grain producing regions are either having issues buying fertilizer or have excessively iron rich soil. And I assume we’re not going to need 2x animals for meat, then.
That would be a problem if the population doubled tomorrow magically, but not if it happened through ordinary growth. We are presently using both the smallest number of people and the smallest share of land for food production at any time in history.
The reason we're struggling right now has nothing to do with the food-production capacity of the planet. It's all a combination of sudden supply shocks and governments being stupid and destructive.
> We are presently using [..] the smallest share of land for food production [than] at any time in history.
per person. In absolute terms (the only terms that matter to the environment), it is by far the largest. Every time the population has grown so far, our impact on the environment has increased. But for some reason, you think this time will be different?
Malthus was wrong 80% of the population ago, and he still is wrong today, for all that he continually finds new followers.