So since there's literally zero space activity in orbit of Earth or other places in the Solar System by the alternate 24th century, it can be surmised that based on this dialogue, at the least Cochrane never made his warp flight, and at most the human race is effectively dead.
Or that there are more humans than ever, all living in ever-increasing poverty on a planet where rampant population growth is not being checked by sudden jumps in living standards that would result from input of alien ideas and appliances, and is not being channeled to colonization of other planets. Although calling that "effectively dead" may not be far off the mark, especially in Trek terms.
It's a bit weird, though: if O'Brien can scan for things as insignificant as satellites, wouldn't his instruments also nicely inform him of the fact that the cities down below have populations in the billions, or in the dozens? Perhaps Earth in his "native" 24th century isn't all that different, even if it has undergone different phases as regards population development, growth and reduction of infrastructure and so forth.
Timo Saloniemi