If you get out much you'll notice a lot of room left.
That "room" consists of deserts, habitats under pressure, and farming lands required to produce food for the billions.
The major fisheries in the oceans are buckling under over-fishing, and the oceans themselves becoming filled with plastic - killing birds, fish and turtles. Ocean warming is already happening, and the catastrophic acidification of oceans is looking more and more likely to occur.
Adding more people into the "room" is no solution.