While there is an argument that minimizing the number of babies is the best solution to achieve our demand by using scarce resources on earth, I think that inventing some kind of solution by modern technology is a better way.
To begin with, it takes lots of time to adjust and restart a new economy if we suppress the number of babies in the world. This is because our society was made based on the fact that there are plenty of humans. Thus, the decrease in the number of humans can cause difficult situations for our society to get used to it. Moreover, the proportion of jobs for services , for example, banks, restaurants, amusement parks is more than half. It means that the decrease in the number of babies can be very challenging for people who work there and can cause a large scale of people who lose their jobs.
Secondly, we are currently working on space research, launching rockets toward space, and experiments in outer space many times in order to find resources there and to provide more space for us. There are many countries doing those things like the United States, Canada, China, Japan, European countries and more. And those countries are doing great things such as sending satellites to the moon and mars. Also, there are many fascinating discoveries. For instance, the satellite in Mars named Curiosity found the trace of the water in the past. It means that there are many more possibilities to achieve our goal with our great technologies than to make policy to control the number of babies.
To conclude, we can highly solve our biggest concern which is scarce resources by pursuing great technologies. The reason why we can say this is that there are many successes by space agencies around the globe. Plus, it is going to be much more difficult to get used to society without enough people.