This is still irrelevant. Back then we didn't have hundreds and thousands of power plants and vehicles polluting the air and damaging the ozone layer. Times have changed, you can't hardly compare 20 years ago to today, let alone maybe 10. Science has enough info to prove that we are a main cause of what has been happening more rapidly than before. Even if we're not 100% the cause, I don't see how a percentage really matters when it comes down to the earth's fate in my opinion. It's just another irrelevant portion of the situation.
