Does the elephant even care that the ants are there though,let alone cause it an itch?There have been umpteen dramatic climate changes in Earths history as well as mass extinctions,the last great one being the reason we are all here.............or were humans responsible for all of that?Nope,so why do people believe that we are now? Humans are part of nature,as such might it not be argued that we are doing what comes naturaly and it's all just part of the grand scheme of things...........cattle produce methane as part of their natural process and yet they carry no guilt,humans produce carbon emissions as part of daily existance and to maintain a standard of life. In theory if enough CO2 gets into the atmosphere then yes warming will occur but in practice the Earth's own checks and balances counter act our tiny contribution surely?