A little more....
I remember a story from the news several years ago, around the mid nineties, I think, when two tenured professors made a wager. They were on opposite sides of the population growth debate. Both were anthropologists, as I recall. The wager was for a ten year duration, and between themselves they set certain criteria, perhaps fifty items; to measure quality of life afer the ten years, based upon growth or decline of the population. The winner? The population growth advocate, of course. While the world is not a perfect place; and evil people on the level of Hitler and Hussein will populate the world occassionally; the world responds appropriately and rises up and squashes them like bugs. Their effect on the world; though tragic; is short lived. But consider the geniuses' effect; say for instance on the technological advances in food production. Those effects are far more reaching and have much more longevity than the evil dictators. So we do need those geniuses to be born; and also need warriors to be born to stand ready to squash the bugs that are born and rise to that bug level. Population growth is good; not bad; and you should support it.
You know; you decry the Hitlers and Husseins out of one side of your mouth; but seem like you would secretly breathe a sigh of relief for all the population that they destroy out of the other side of your mouths. That is just wrong; and you need to repent of that.
So, as you say, we need more arable land; so let's cut down more jungle to make it so!