I am going to give a baseball analogy to "global warming."
The great 1927 N.Y. Yankees was stacked with talent, including Babe Ruth, Lou Gehrig, Herb Pennock, Tony Lazzeri, etc. The Yanks also had a good luck charm in a mascot-bat boy by the name of Eddie Bennett.
Eddie would do things like shake a home run hitter's hand after the Yankee batter crossed home plate. The Yanks pitcher Wiley Moore would toss the first warm-up pitch to Eddie. Ed Bennett was the roommate of Yanks great pitcher Urban Shocker.
Eddie Bennett was part of the team that won 3 World Series and 6 pennants. Eddie never played, but his good luck charm was considered a valuable part of the team.
You can never truly measure how much the Yanks' success was due to each player, coach, manager, fan support, or their batboy Eddie Bennett. It's the same way that you could never measure how much of the earth's climate is due to the sun, galactic rays, the planets, or man.
Attributing all of the earth's climate to man is like attributing all the Yankee success to Eddie Bennett.