First off, the author is prodding people into action by scaring/alarming them. Thus, the entire point of this article is to highlight many of the bad long-tails (note I did not say WORST long tails, eg Clathrate Gun, or phytoplankton crash leading to global anoxia, because they almost instantly wipe out human life), which could give the impression we are more screwed than we are;
In other words, all of these happening is not a probable outcome (the article is not based on a statistical inference or climate model). However, as we climb up the \delta +C ladder, all of these effects/implications become increasingly probable. If you crank up \delta +C to +5C for instance, at least half if not all of these will occur (due to positive feedbacks eg albedo);
I would not say we are beyond the hope of any action at this point. There are two sub-sets of conventional actions being discussed in the context of official orgs, eg UNFCCC at the moment:
-Mitigation- reduce emissions directly,- eg turn off coal plants or plan to do so to dozens within the next few years, massively scale up solar adoption
-Adaptation- take actions now to reduce devastation from past [inertial] and unavoidable future emissions, e.g, invest in heat-proof seeds and crops for certain tropical biomes
Broadly, both are still possible. The former is notably more susceptible to political landmines and fossil fuel monopoly blocking than the latter, so a lot of climate scientists are urging folks to focus on the latter. Is it enough to save us? In terms of physics and climate systems--no, but metaphorically it could reduce pain like palliative care for the swathes of humanity, largely from tropical regions, who probably wont make it. The real heartbreaker here: mitigation is crucial to avoiding all the evil long-tails, but our poltical and economic systems seem allergic to it. How about just a little mitigation- eg lukewarm Paris implementation-- do we still miss some of the worst evils? Very unclear-- now we need to consult the statistical physicists.
There's a third bin too which I would call pure engineering solutions; These could involve for instance, building plants to suck CO2 out of the atmosphere [1], seeding the oceans with certain chemicals to increase Co2 oceanic uptake [2], or straight up engineering the atmosphere [3]. I listed those in increasing order of possible risk/backfiring (complexity of the climate engineering operation).
I invite anyone to clarify or add to which they think are feasible and infeasible amongst these; I listed this all for context, and not to advance a particular legal, moral, or political argument, although clearly there are a litany to be made.
[1] http://www.climeworks.com/
[2] https://www.sciencedaily.com/releases/2007/06/070608142214.h...
[3] https://www.wikiwand.com/en/Stratospheric_aerosol_injection_...