One of the main tools NASA uses to measure CO2 is

satellites

rockets

radar

sonar

The main tool NASA uses to measure CO2 is satellites. Satellites equipped with instruments such as the Orbiting Carbon Observatory (OCO) and the Atmospheric Infrared Sounder (AIRS) are used to collect data on the concentration and distribution of CO2 in the Earth's atmosphere. These satellites provide valuable information for scientists studying climate change and carbon cycle dynamics.

1,2,3,4

I'm sorry, but I don't understand what you mean by "1,2,3,4." Could you please provide more context or clarify your statement?