There is absolutely no reason we need to continue increasing the human population when we clearly have trouble using and allocating the limited resources we have now. Doesn't concern me one bit if birthrates are falling. I might start to look into it if population falls below a couple billion, which it was for all but the last 100 years. But population is project to continue rising until 2084 anyway, which means I don't need to think about this problem at all for the remainder of my life.