Arctic ice has 1400Gt of carbon locked up as methane. [1] This is equivalent to 1400/10 = 140 years of human 2016 activity. [2]. Methane also has a stronger effect than CO2. If ice starts to melt, we are doomed. [1]: https://en.wikipedia.org/wiki/Arctic_methane_emissions#Contr... [2]: https://www.co2.earth/global-co2-emissions
It's safe to say we're soundly screwed, and probably were screwed before we could realistically do anything about it. Anything we do now short of killing off 80% of the population and the other 20% living like native tribes men, won't have any real affect, it might slow it. Unless we come up with some solution the counter the feedback mechanisms and extract/recapture these gases from the atmosphere.