What factors in having fewer babies

Following current trends, the human population would start to decrease in the 2080s. With all the real problems that could cause human extinction, the lack of interest in procreation is hardly worth mentioning.

Current trends cannot continue until the 2080s. If we don't curb global heating soon, and various problems of pollution, the population by then will be much smaller than now.

We can't maintain the current population and give a good standard of living to everyone, barring a spectrum of miraculous scientific advances which one cannot count on. We need it to decrease, and it will.

There are three ways for the human population to decrease: the humane way (birth control and abortion), the depression-filled way (mass celibacy), and the gruesome way. We are heading for the gruesome way.