i've been studying climate forecast models for a while. seems important,
you know.

most of them are pretty solid for what the researchers are trying to
model, which is the equilibrium state of atmospheric gas mixture models
and ocean fluid mechanics under some assume set of constant "anthropocene"
parameters. it's a simplified form of the same kind of models you use when
forecasting the trajectory of a hurricane or some other large-scale weather
structure.

the pattern of analysis is basically what you'd expect, two navier
stokes models for the atmosphere and ocean, both equipped with extra
terms for representing storable thermal quantities, with a simple boundary
interface coupling. some models introduce terms for ground heating effects
or abstractions of ecological gas contributions, specific fluid models
to match empirical variations in polar ice heating effects, and one model
makes an attempt to propogate gravity waves through the atmosphere. i know a
proper mechanicist would look at this and balk, but given the computational
considerations i think this is actually very coherent.

integration is performed by constant step finite difference over a fixed
grid. this has all the obvious problems, but the scale of the simulation
task usually precludes using better geometries or adaptive methods. there
is certainly no lack of applied mathematicians working here, and i've found
plenty of attempts to address this, but the earth does seem to admit many
clever formalizations.

these models behave surprisingly well when massaged to fit satellite data,
and don't diverge very much at all over forecasts about five years long. longer
projections are less viable for forecasting, as of 2018 no model has provided
good results for 20 year runtimes.

it's difficult to know how much better fits of these models can get, because
the first viable satellite datasets for this application appeared in the late
80s and the first one that really worked was released in 2006. the climate
has obviously changed a lot since the 80s, and even since 2006, so climate
modelling efforts are sampling from a pretty rough part of "climate model
phase space".

the way the ipcc interprets these models is strange. the assessment reports
focus nearly exclusively on the weakest projection ranges, and their formalized
scenarios have many more weaknesses than the analysis i've seen in climate
science journals. their approach is to pool resource into producing long runs
of "established" models (hadgem2) at very high resolution, which results in
an absolutely massive amount of integration data, and do simple statistical
analysis on those results.

this is very hasty divination. i don't mean that in any kind of "this is
unscientific!" tone, all climate forecasting is useful divination, but
they are working without much confidence. after every report the journals
are briefly flooded with scrutiny on that data and analysis, philosophical
critique, and alternate interpretations, often from researchers who worked
on the project themselves. i am largely unaware of what happens in the
course of producing those reports, but my impression is that the effort is
structured in a way that guarantees the production of clear indicators for
policymaking where there would otherwise be vaguery. a necessary sacrifice
of a mathematically-aware approach to the problem for the sake of presenting
quantitative results to provoke political action.

those of us in positions unrelated to parliamentarian decisionmaking and
media narrative shaping can safely disregard the conclusions and confidence
intervals in the report. notably, the 1.5 degree scenario is intended for
an audience of people who can use it as leverage in government or corporate
contexts. if you are interested in actually knowing how the climate is
changing, it is absurd. it seems like the only really meaningful result of
the ipcc report process is their simulation and synthesis data, all of which
is thankfully public.

outside of the ipcc reports, interpretations are a bit less disappointing. the
uk's met office and the noaa have a methodology of representing human
emissions as a variable process driven by population and agricultural growth,
augmented by some notion of technological advancements slowly reducing
emissions. they represent many growth processes as purely market-driven,
which is philosophically questionable but results in an easy to analyze ode
model. this model is added as another coupled equation, so climate-driven
agricultural adaptation and some regional differences in human response
are represented.

interpreting these requires lots of caution and reflection on how the
human activity model behaves, but it is far less silly than the ipcc's
fixed emissions curve system. an interesting aspect of the anthropocene is
that it's named correctly, we have become a substantial geological process,
and if we are to find any useful structure in the aforementioned rough phase
space we will need to model ourselves similarly as the rest of the system.

from what i have read so far the most sensible scenario in climate models
is for the magic global warming meter to pass 2 degrees celsius within 30
years, and pass 3 within 60. models that suggest this are the ones where
carbon and methane emissions continue to increase in the short term, which
is of course a little easier to believe than a sudden drastic reduction and
global cooperation to transform every large industrial society. the americans
haven't even stopped fracking.

that magic global warming meter doesn't actually mean very much. it's
calculated as "global mean surface temperature", which signifies nothing
besides the planet looking a bit warmer from distant orbit. the regional
surface temperature, atmospheric gas mixture, and ocean current models
are the ones that you can actually draw some expectations from. sketches of
these are available as "representative concentration pathway" packages, which
are base datasets of a global climate model that can be adapted to regional
forecasting applications without needing to run the whole coupled model again.

in these scenarios, the continents warm much faster than the ocean, meaning
that mean 3 degree increase is actually a 6 degree increase in many areas,
especially north america, europe, and siberia. under efficient market
simulation, human agricultural activity and population growth is, uh,
reduced substantially.

the way people talk about these things in the anglosphere is interesting
to me. even in context of policymaking it is as if there are only three
acceptable posturings: you can deny there will be any significant change
in society due to climate change, you can declare it the apocalypse and
demand immediate societal change to prevent it, or you can declare yourself
agnostic and play both hands interchangeably. this permeates pretty much
every discussion about global climate change outside of research circles.

we do not talk this way about hurricanes, even though we model them the
same way. we do not ignore the massive swirling monster in the distance,
we do not declare it our responsibility to disperse it fully, and we
certainly do not remain indifferent to its existence as if it is someone
else's concern. instead, we try to discern where it's going, we fortify the
affected areas, evacuate if necessary. sometimes it is used as a weapon,
opportunists use the expectation of destruction to change the balance of
power in the region, or use it as an excuse to assert a policing agenda.

it is a change that can be understood, and a strategy can be formed around it.

here i'll disregard all the qualifiers you need to talk about societal
forecasting with proper self-awareness. i just want to have fun with narrative
drawn from these models.

anthropogenic climate change will destroy this civilization, and drastically
change other civilizations. it will not destroy humanity, nor will it
destroy life on earth. its primary effect will be directed at us, where "us"
is the group of societies where english is the lingua franca and trade is
coordinated without any significant boundaries or threat of sanction. we're
the ones who have to take the +6 right to the face.

we have failed to fortify, we have no real intent of starting, and it is
not possible for us to weather the storm.

the only option we have to avoid disintegration is large-scale war to secure
better positioning before significant impact on agricultural capability,
but we lack any strong military leadership or mid-level coordination. the
american military and its allies have the resources to take any position
they might want, but they are encumbered by organizational dysfunction, and can
barely put one foot in front of the other.

really i think we should just call this one done. it had some good times,
but now it's just too fragile and slow to keep going.

of course, collapse of a polity looks nothing like the fire and brimstone it
is often imagined as. we might have famine, border skirmishes, less likely
a plague, but it's not like the cities will be razed to the ground or the
planes will stop flying.

it's just time to design new civilization for these places, and prepare
to make the transition as graceful as possible. we need to start gaining
understanding of what agriculture, urban planning, authority, infrastructure,
and military development need to look like in a very different earth. maybe
it's time to bring back walled cities, or maybe it's best to reconceptualize
large-scale agriculture as a synthetic industrial process. maybe we should
automate small-scale warfare as much as possible, maybe it's time to plan an
independent venetian manhattan. there isn't any way to answer these questions
right now, but this is the most valuable perspective on the future. what
can we do when the old authorities and the old ways disappear?

it's also time to shake off the idea that a globe-spanning military can
fully isolate the civilian populace of multiple continents from militant
violence. saving the pax americana just isn't possible in our era. like in all
past societies where an imperial military lost its power and organization,
civil fortification and defense will become the responsibility of regional
authorities. that might happen smoothly, or that might involve small wars in
places that were previously considered unified and defended, who knows. maybe
china will take the west coast, maybe a cartel will bite at its heels. maybe
the east coast will revive its rail infrastructure to save themselves from
overreliance on imports, maybe turkey will take greece, maybe france will
conquer all its neighbours when the nuclear and rail investment starts
paying dividends.

we have to change how we think about society, where "we" is everyone capable
of planning the future or working to realize it. the constraints and support
we have now won't last very long, and the world that comes after it will
look a lot less stable, a tumultuous era. our societies will be desperate
for anything that can make them safe, for anything that can keep them fed,
for anything that can help them grow. they will also want new identities, new
relationships to their neighbours, new styles of life, maybe even new religion.

dropping the narrative, i don't really have any strong prediction if climate
change will be the major driving factor of societal change in our time. after
all, the models only hold up for 5 years, the analysis isn't exactly sound,
and the sources of lots of atmosphereic and ocean factors are still unknown.

this is just how i've started to think about the future as i study changes
to climate, economics, medicine, mathematics, weapon systems, and military
organization. even though it seems fairly banal now, this is already a
rapidly changing world, headed towards fundamental shift in how societies
are organized, through disasters and conflict.

but if you can steel yourself for the nasty parts of this era, there's quite
a lot of room for creativity.