While this thread is focused on pointing at recent measurements indicating that the responses of key feedbacks (most prominently now due to wildfires) have now (2015) reached bifurcation points (not tipping points) where their rates of responses have abruptly accelerated (possibly triggered by our current Super El Nino event). While looking at satellite measurements is reassuring because their uncertainties are relatively low, what is most important is that Earth System Models, ESMs, not only capture such non-linear accelerations, but also the synergistic interactions between the various feedbacks (given that: "All models are wrong, but some models are useful), as this synergistic interaction will give us all a better idea where climate change is going in the next few decades. In this regards, in addition to they El Nino triggering of droughts and associated tropical rainforest wildfires, I list some other feedback synergies that it will be important for state-of-the-art ESMs like ACME to accurately model, if policy makers are going to have reasonable model forecasts of what is coming (assuming that 2015 is a turning point):
A) Permafrost degradation is not only accelerated by wildfires (currently not modeled, & especially not the burning of the peat & forest litter) but also by the polarward migration of burrowing animals and forest killing invasive insects.
B) Not only do droughts (including that induced by our Super El Nino) promote tropical forest wildfires (with high CO2 emissions), but subsequent flooding leads to submergence of the dead vegetation that leads to accelerated CH4 emission in subsequent years. Also, tropical rainforests generate atmospheric conditions that promote rainfall, so the current high rates of deforestation & tropical wildfires will result in less future rainfall, and more droughts (even without El Ninos). Also, I note that run-off from tropical rainforests contains high levels of CO2, so we can expect the next round of floodwater to carry unusually are amounts of CO2 into the oceans, thus accelerating ocean acidification.
C) Both paleo-evidence and Hansen et al. (2015) point both to the synergy between the bipolar seesaw and both Arctic Amplification and also to planetary energy imbalance, via changes with both polar sea ice and the MOC.
D) I note that both increasing ocean heat content and ocean acidification contribute to a trend indicating a reduction in the size of plankton which synergistically results in less CO2 absorption, less dimethyl sulfide (DMS) emissions, and less CO2 sequestration into deep ocean waters.
F) Accelerating global deforestation (due to droughts, insect damage, wildfires, etc.) result in reduced VOC emissions, which means less negative feedback.
G) The increase in tropical atmospheric deep convection works synergistically to promote stronger El Nino events, more positive cloud feedback and poleward telecommunication of atmospheric energy thus promoting Polar Amplification.
Such synergies between non-linear feedback mechanisms could lead to future tipping points that will be extremely difficult to reverse such as:
A) A possible atmospheric flip to an equable climate (possibly by the end of this century).
B) Abrupt collapse of the marine portions of ice sheet (possibly starting in a couple of decades time).
C) A possible MOC collapse (if the marine portions of the ice sheets collapse).
D) A possible abrupt transition to a Canfield ocean (with high sulfide producing bacteria).
