Perhaps all of the carbon emissions from cavemen roasting...
Climate Shift
Climate shift is demonstrably real, we have evidence of climate shift happening several times during the history of Earth. We have geological evidence of glacial migration that happened hundreds of thousands of years ago, where did they go? Perhaps all of the carbon emissions from cavemen roasting wooly mammoths (now extinct) caused global warming in the distant past. Perhaps it is an unavoidable cycle that isn't well documented because of the extremely long cycle length? We should be concerned with the unavoidable climate shift, each and every one of us should be deeply concerned. Be it man made climate shift or a natural cycle, it is still climate shift. Unfortunately those among us who realize that we need to learn how to live with minimal impact on mother earth are openly mocked as hippies, and those who prepare themselves for surviving some great calamity are openly mocked and tin foil hat wearing nutters. Meanwhile the great minds of our society are pointing fingers and making measurements trying to assign blame. And the great solution that has been presented is to carbon tax our way out of this mess, which of course can only be issued by the threat of force. I don't agree that anything is "resolved".