SOURCES FOR FLIGHT TRACKING DATA:
https://www.flightradar24.com/data/statistics
https://www.transtats.bts.gov/Data_Elements.aspx?Data=5
https://www.bts.gov/explore-topics-and-geography/topics/air-traffic-data#:~:text=%20Air%20Traffic%20Data%20%201%20US%20Air,Revenue%20Passenger-Miles%208%20Seasonally%20Adjusted%20Data%20More%20
We used these external sources to get data on the total number of flights in 2019,2020 and 2021 till date
SOURCES FOR INTERNET USAGE DATA:
https://www.statista.com/topics/1145/internet-usage-worldwide/#dossierSummary__chapter1
https://www.statista.com/topics/1145/internet-usage-worldwide/#dossierSummary__chapter5
We used these external sources to get data on the fraction or percentage of people using the internet.
SOURCES FOR CO2 EMISSION DATA:
https://www.businesstraveller.com/business-travel/2020/06/05/aviation-sees-the-highest-pandemic-drop-in-co2-emissions-research/
We used these external sources to get data on the reduction of concentration as well as percentage of CO2 in the atmosphere.