We could well be at a tipping point now.  As permafrost is beginning to melt, the methane and co2 released could start a runaway greenhouse effect.   Our historical record from the mid Pliocene shows sea level rise of 25 feet or more from similar conditions as our current levels of CO2.  We may have failed to adapt in time, but it is better to at least try.  Admitting the problem is a first step.  Exxon's greed didn't help.