The difference between the ice ages and the climate we had until the 90's is a 30% difference in CO2 levels. We have already raised CO2 levels by 40% as big or bigger diffrence then the difference between the hight of the ice ages and the climate we have come to expect.
If the Methane in trapped in the permafrost ecpapes it would be like raising CO2 levels 25000% if it happens we are are all dead.
It's already happening, if we don't act now to radically reverce not just slow the the increase in CO2 levels climate change will be like a rock rolling down a mountain impossible to stop or control.