Sigh,
I watch in horror each day as the rate of progression of catastrophic climate change inexorably increases. All the while, as expected, the political climate in countries all over the world goes deeper into denial, and people behave like people procreating and expanding as if the world were an unlimited playground.
The trends continue unabated and are accelerating as expected. The arctic ice is failing in ways that are almost beyond words. Yet, we have become so inured to it, that it hardly makes a dent in our perceptions. Rather than focus on the dominant factors we focus on the least important ones seemingly in the vain hope that somehow things are not as bad as they seem.
The ice thickness is failing rapidly. The Nares straight and the Beaufort have become monsters eating the last vestiges of "old" ice. We appear surely on pace to go well below 4 million km^2 of ice extent. Due to the silly 15% ice cover per many square kilometers being counted as all ice, the real condition is far worse.
Based on volume collapse, we look likely to see the first day with essentially no ice in the arctic ocean to arrive on schedule by the mid 2020s - and probably earlier - 2022-2023.
As we approach that, the weather is getting ever weirder, not just because of the general warming, but even more because of the weakening heat engine. Greenland will act as a bulwark to pause that collapse for a few centuries. But, the climate will be nothing like what we have known.
I fully expect that by 2030 that we will see:
1) a dramatic shift begin in the climate as we begin seeing ice free periods in the arctic ocean.
2) dramatic shifts continuing to accelerate in the decline of the deep oceanic currents that were driven by the ice.
3) anoxic zones expanding in both the atlantic and pacific oceans by the shifting and dying ocean currents
4) large scale impacts to ocean ecosystems as a result. These have already begun. By 2030 they should have truly dramatic impacts on fisheries.
5) weather shifts in rain and drought that jeopardize crops in major food producing zones.
6) a near complete collapse of the availability of fossil fuels in Africa to Africans that combined with weather shifts, resource wars, drought and pestilence lead to a dramatic increase in people trying to flee to safer and better places. That then in turn leads to war in Africa and in the middle east and possibly Europe.
7) a near complete collapse in fossil fuels for most of oceania.
8 ) an oscillation in the weather patterns where winters are warmer in general other than in the northeastern US, and where the late summer pattern shifts to a polar jet stream trying to orbit Greenland with dramatic impacts on the whole northern hemisphere.
9) the collapse of the ice bridges on several major glaciers in Antartica, particularly in West Antarctica (Thwaite's especially) resulting in massive impacts on the ocean systems around Antarctica. These are already underway as the distance to bottom under the ice edge is dramatically impacting the Krill along with massive over fishing by humans
10) resource wars. We already have Iraq and Syria in flames. Next up is Venezuela in a cold war like struggle over control of their oil. That began several years ago and will get progressively worse.. Next is Iran. That could quickly turn into a hot war with several potential outcomes, none of which are good. Over a dozen war games run on those scenarios have the US losing in all cases. Many lead to the loss of Saudi Oil terminals, and plummeting global oil supplies leading to collapse of markets and economies all over the world. I would not be surprised to see Turkmenistan and the other -stans, and the central European states consumed in these wars.
11) oscillating areas of drought and deluge as the climate shifts
12) even more massive translocation of people in many regions, not just Africa.
13) several nations breaking out of the pause on nuclear weapons development as a hedge to protect their perceived national interests. Chief among these: Japan, Taiwan, and Saudi Arabia (before or after the collapse of the House of Saud). The current "cold" war like battle over resources may turn hot in some areas by 2030 leading to the exchange of strategic nuclear weapons. Other tensions over movement of peoples, resource limitations and the like may similarly lead to other wars.
14) many nations seem likely to shift to nationalistic or tyrannical governments in response to these pressure. The tendency will be to blame "them" for "our" problems in many societies. And that will inexorably lead to hostilities small and large.
In short - I see a pretty hostile future ahead by 2030. These events may unfold more slowly. Cooler heads may prevail for the worst parts involving humans. But our history as a species suggests the opposite.
By the 2050-2070 timeframe I fully expect that the last of the ice in the Arctic ocean will be gone. It will remain gone for over 100,000 years. Greenland will be under intense melting pressures. And in millennia (or less), that ice too will be lost. At that point, the atmospheric engine in the northern hemisphere dies. And the northern hemisphere converts to an equable climate system. The oceanic currents die for a time in the north leading to massive dead zones in the major oceans, which then convert to emitting hydrogen sulfide rather than oxygen. Life on earth becomes extremely difficult for all species everywhere. The key events here will likely be the collapse of the northern tundra, and the boiling of the clathrates from the shallow seas of the arctic ocean. The pulse of carbon into the atmosphere will render all human actions irrelevant. We will then repeat the PETM - possibly worse.
Our time to act to lessen the near term disasters is all but gone. Likewise, our chance to avert the world shifting to a hothouse earth in a rapid fashion is all but gone.
Attempts to limit global warming to 1.5 C failed. This is now long since in the rearview mirror. So to is 2 C. 2.5 C might be doable with massive concerted global action. That won't happen. More likely is that we will ultimately see a 10 C rise - a hothouse earth. Antarctica will be the control on that. It will take a very long time for the ice there to melt. And just maybe, the climate can recover over the next several hundred thousand years to something similar today, allowing some new species to ascend. They, whoever or whatever they are, will have the disadvantage and advantage of not having fossil fuels to destroy themselves. They are unlikely I think to be the descendants of the human line.
Sam