Toby Ord welcomes population growth:
[A]lmost all of the press focuses on the downsides of population growth but neglects the upsides. These upsides may even outweigh the downsides, making a larger population a good thing overall. One example is the rapidly growing information economy. If someone makes a hammer, only a few people get the benefit, but if someone records a new song, writes a computer program, or invents a new technology, everyone can benefit. These activities thus produce more value the more people we have. With twice as many people doing jobs like these, we could all get roughly twice the benefits (more art, culture, science, technology), or they could work roughly half as many hours. A larger population thus has the potential to make life much better, so long as we can find the resources to support it.
Previous thoughts on overpopulation here.