There is no stopping at +2 degrees
The Paris climate accord is predicated on the assumption that curtailing carbon emissions and other causes of climate breakdown will halt global heating in its tracks, neatly at a level that allows us to live on in more or less the usual comforts. Therein are fallacies too numerous to mention, but one overrides all the rest. That one is the disregard of feedback mechanisms.
Already, at whatever temperature above pre-industrial average we currently are (let’s say 1°C), several effects of heating are definitively observed that in turn have their own effects on climate. Forest die-off and desertification have the twin effect of removing the vegetation’s carbon-absorbing function and (through decay) releasing the stored carbon into the atmosphere. (So do cutting and burning, though these are not direct heating feedback mechanisms.) The loss of polar ice’s albedo effect (white surfaces reflecting sunshine) magnifies solar warming. And, the big bomb, Arctic methane is thawing on land and under sea and burps forth in immeasurable quantities; the methane has a greenhouse effect several times stronger than carbon dioxide’s. Each of these feeds itself and the others. So even if carbon emissions from fossil fuels were zeroed out tomorrow, these other warming mechanisms — already sufficiently fueled by existing accumulated atmospheric carbon — would take up the slack and keep accelerating the climate train towards a wreck.
So it doesn’t matter much whether we stop at +2C, or +1.77C, or wherever we are now. We’re in a warehouse full of nitroglycerine with a string of firecrackers going off. Putting out the match that lit the string is no longer the issue.
Therefore spending political energy to obtain adherence to the Paris targets is a waste, except insofar as rapid movement towards the targets may demonstrate the feasibility and economy of carbon-free energy. But likely as not, much of the Paris implementation, where it happens, will deflect into pointless diversions. In France, they’ve recently banned burning cut brush in rural areas, largely because it emits carbon. (To be fair, it’s also because of steeper forest-fire risk from drought summers.) Now everyone who tends land has to burn petroleum to cart the stuff to dumps (where it decays and releases the carbon anyway). They’re also reportedly thinking of banning use of fireplaces and wood stoves. This is not serious. But it’s likely what you’ll get wherever you harp on the Paris accords.
If it’s true that the feedback mechanisms make nonsense of the idea of stopping the heating at a convenient point, things look pretty grim. But there may be a solution: massive, rapid carbon capture, which can only be done through…nature. Regenerative farming (a variant of organic), which nurtures soil microbes that capture and sequester carbon (and thus nourish plants), can be expanded fast to a scale that rolls back accumulated atmospheric carbon within a time frame — say five or ten years — that may slow down the feedback mechanisms, and offset the effects of those that can’t be slowed down in time. Let’s focus on that, rather than implicitly endorsing the idea that we can screw up the climate to exactly the extent we choose, and hold it right there.
