We have reached the climate tipping point much more quickly than anybody anticipated. But with methane outgassing in arctic tundra and beginning to boil up from under the Arctic Ocean, Greenland ice turning black due to lack of snowfall, and rapid warming of northern waters, the stage is set.
Nobody has any idea when dramatic changes will overtake us, but the form they will likely take is becoming more clear. It is likely that, when arctic temperatures spike during some summer soon, the jet stream will fail because the temperature difference between the atmosphere in the far north and mid-latitudes will not be enough to enable it to continue.
Basically, that will mean that all cities in the northern hemisphere that are dependent on continental air circulation for ventilation will fail to get that ventilation. Most inland cities in Asia will be under immediate threat from pollution levels beyond anything ever seen before or imagined possible. In regions where there has already been an effort at pollution control, the danger will build more slowly.
This will only be a small part of a very complex process that is fraught with unknowns. If it happens before the current California drought breaks, the southern half of the state may become uninhabitable when ground water runs out. However, it is possible that this region will become susceptible to hurricanes as central Pacific waters continue to warm. Elsewhere in the United States, an entirely unpredictable cascade of events will unfold, that will likely include general drought punctuated by extreme storms. Europe will also become susceptible to weather of extreme local violence. In general, as the temperature of the stratosphere rises, the number and intensity of these storms will decline along with air circulation and a decline in the strength of all ocean currents.
Summer air temperatures will not be survivable in many circumstances, and worldwide climactic disturbance will lead to food shortages even in developed counties, with unrest, war and revolution as the inevitable result.
This is going to happen. From the early seventies until the present, there was insufficient leadership in the United States due to the false global warming debate that was developed by profiteers who wanted immediate financial returns without regard for the future. Without American leadership, world efforts to prevent this from happening were colossally insufficient. There has been no leadership whatsoever in Asia, and yet the growth of Asian economies is the most prominent single reason that the change has accelerated so quickly.
Now that the methane release is under way, it is, quite simply, too late to reverse the process. We will experience a warming spike just like the ones that have climaxed other ice ages.
Unfortunately, the future has arrived earlier than anybody expected.