> The New Shepard uses a rocket engine, called Blue Engine 3, that runs on fuel combining liquid hydrogen and liquid oxygen. When these elements react with each other, they generate a tremendous amount of heat and the propulsive force to get the rocket off the ground.

> Since there's no carbon contained in the fuel, no carbon dioxide is emitted during the launch or into the atmosphere, Eloise Marais, an air pollution researcher at the University College London, told USA TODAY via email.

> Darin Toohey, an atmospheric scientist at the University of Colorado, Boulder, agreed, telling Live Science that the main emissions from Bezos' rocket would be "water and some minor combustion products, and virtually no CO2."