Even skeptics agree that humans contribute to the CO2 levels. We probably will never know for sure if this is a pivotal factor or only the contributing one. It could be that we accelerated what was coming anyway. But even if our contribution is meaningful, it most likely caused an avalanche effect. A man can cause an avalanche, but it is beyond the man’s powers to stop it. Sadly, that option is not a part of any policy decisions contemplated now.