As you say, a climate projection should be judged on its ability to track the quantities of certain gases and it seems to have done a remarkably good job in this respect. (judithcurry.com)
Certain gases in the atmosphere, such as carbon dioxide, play a crucial role in determining the earth's climate. (usask.ca)
Scientists know that certain gases trap heat and act like a blanket to warm the planet. (ucsusa.org)