Is there any way to see an actual or estimate figure about how many people are flying (may be in airliners, only, if that helps) at a given point of time?
If there's an airplane's count instead of people (I don't expect that number to be public), that'd be enough, too.
While not total, Flightradar24 seems to come fairly close to offering comprehensive and live data.
Flightradar24 started as a hobby project in 2006 when two Swedish aviation geeks decided to build a network of ADS-B receivers in Northern and Central Europe. In 2009 we opened up the network, and made it possible for anyone with an ADS-B receiver to upload data to the network.
Figures At-a-glance
- Largest ADS-B network in the world with over 10,000 connected receivers
- Over 150,000 flights tracked per day. See our Statistics page for daily stats
- 1.5+ million users per day
- Number 1 app on AppStore in 120+ countries
- Number 1 travel app on AppStore in 150+ countries
- 30+ million app downloads
- Used by most major airlines and others in the aviation industry, including Airbus, Boeing, and Embraer
A similar site, MarineTraffic, uses AIS tracking to show the live positions of vessels, as well as details on ports and lights.
There's a variety of ways of calculating this, and obviously it depends on seasons, time of day around the world, and some events affect it (Chinese New Year, for example).
This has been asked on Quora and the estimates range from 500,000 to 970,000, depending on mathematical calculations, estimates, or stats from Boeing or Flight tracker.
Check out https://www.flightradar24.com/, which shows all flights that are currently in the air. At the moment its 13628. If you assume an average of 100 passengers per flight (Wild guess), that comes out to be 1.4 million people in the air.
It's also interesting to observe how the flight patterns change throughout the day: at the moment (9am US east coast) the North Atlantic is almost entirely one way from Europe to the US. This will flip later afternoon.
