I've been working on fine tuning my sim for incorporating multiple factors. I've been working on this for a couple of years now.
My Sim: Problem Multisolving Sim 1.
What it does:
1. Population growth which is congruent with the 2020 Lancet Study (roughly median range).
2. Recognizes the need for Natural Gas to be a bridge fuel to keep energy costs low and to provide energy when Renewables are not functioning.
3. Recognizes the need for a global nuclear energy foundation in the strive to keep temperatures at 2 or below, and to keep energy costs low.
4. Energy Subsidies gradually phase out to stop market distortion while simultaneously making sure that the cost of energy and the market price of electricity are lowered throughout the century.
5. Recognizes the need to keep energy costs low to prevent social unrest.
6. Recognizes the need to gradually phase in and then plateau a carbon tax so that economies have time to prepare and so that the tax does not eat into welfare as seen in Finland with their 150 euro carbon tax.
Carbon tax rises to 51 dollars gradually, in the first half of the century, then stays at the same value for the remainder of the century. Nations will have the better part of a century to adapt to a 51 dollar per ton carbon tax, resulting in reduced economic and social friction.
Carbon Tax is kept to balance the budget. However in real life this tax can be phased out by 2089 and other taxes can take up the slack. In the real world, Carbon Tax should be 0 by 2089 under this model.
7. Emissions Standards policy under the carbon tax superheading does not preclude natural gas. Although emphasis is given to Gas CCS.
8. Economic growth is emphasized to lift people out of poverty and degrowth is ignored.
9. Does not start the acceleration of electrification till Sub-Saharan Africa has reached a per capita GDP of 15,000+ dollars, which while not a good proxy, does atleast signify that the people in the Congo have the choice to not work in Cobalt mines if they so wish, even if we assume that GINI remains at 40 and their GDP per capita may be at 85% of the rest of Subsaharan Africa ( which is further ahead nominally than where China is today on a per capita basis), hinting that this newfound prosperity will likely give them better choices.
10. Deforestation is lowered at a rate which seems politically feasible.
11. Afforestation is present at a level which does not threaten tribal land.
12. GDP is at a value ($851 trillion) which signifies that the World should be able to adapt to the warmer world, as the model unfortunately does not factor in adaptation which I expect will keep us safe, like it has in the past (deaths from disasters have gone down by 97% in the past 100 years thanks to prosperity and technology, all the while population and temperatures have risen). A realistic growth of between 2.3 and 2.5% globally in this century will see poverty disappear.
This high GDP could also be a proxy for greater agricultural production and distribution, implying better and more productive methods for farming.
13. Carbon Dioxide levels do not fall so fast, so as to blunt afforestation efforts as trees can extract more CO2 if there is more CO2 in the atmosphere, implying CO2 driven plant growth. It's a delicate balance between plant growth and CO2 levels, but as you can see in anthropogenic CO2 removals, I have almost reached breakeven (net zero). Although net zero is achieved by 2056 if natural factors are included.
14. Bulk Material for Mineralization does not exceed the size of the coal industry till they both meet (as the coal industry falls), hinting at coal workers being able to find new jobs. The same with the gas industry, the gas industry expands as the scale of CO2 extraction expands, with much of the expansion coming from Gas CCS, here, the scale of CO2 sequestration is only slightly greater than the size of the Gas industry, meaning that expertise is not lost and there's sufficient capacity to sequester the needed amount of CO2.
15. Particulate pollution falls drastically.
16. Ocean Acidification almost rises up to 8, signifying an improvement and then a plateau.
17. Sea Levels do not climb to catastrophic levels. They halt at 0.56 metres.
18. Heat deaths can likely be mitigated by more AC units and lower impact on the climate due to nuclear and renewables and low reliance on fossil fuels (only about 8.44% by 2100, out of which nearly 80% is Natural Gas, almost entirely CCS).
19. Area required for CO2 removal does not exceed the area of India, although this does not include the area needed for DAC (as far as I am aware). All technological solutions remain below 30% of their potential.
20. Economic impact of covid under assumptions is extended for consumption and duration of impacts on consumption from 1 year to 3 years to reflect the coming recession.
21. GDP per capita growth rate for the near-term is reduced to 1.8% to match the values we see right now for 2022 (3.8% World Bank) and increased to 2.5% for the long term with a transition time of 10 years, ensuring that economic growth continues in the model. Due to this, India suffers, but in the real world, it's entirely possible that India will do much better, as this model has limitations. The same goes for World GDP, it could indeed do better and break the Quadrillion dollar mark by or before 2100.
22. Adaptation is not included in this model, so imagine all deaths (including species extinction) and crop damage to be reduced by 97-99%. I'm assuming that a Quadrillion dollar world economy has enough resources to protect humans, the biosphere and resist effectively sea level rise and heat. Which seems to be realistic as increasing prosperity in the past 100 years has made everything better, so to speak. Violence, Wars, Famine, Poverty, etc. are all down in the past 100 years. Life Expectancy, Food Production, Health, etc, are all up. This is not to say that progress is inevitable, it can be reversed, but here I am extrapolating from past trends that better technology and more wealth means a better world.
23. While the model shows that the temp is at 2.0 degrees Celsius. It is actually at 1.95 degrees Celsius, if you hover your cursor. The less ambitious Paris Climate Goal has been achieved. This is trending downwards.
24. I would argue that this moderately warmer world of +1.95 degrees compared to the preindustrial world, given enough time to adapt to it, might actually be better for life on Earth. Although, +1 degrees or +0.5 degrees would probably be better. Life, uh, finds a way.
(I say this, because in the historical record, warmer periods of time with greater oxygen levels, lead to huge bursts in life, the Cambrian Explosion, the age of dinosaurs, etc. The one exception to this is the Permian Mass Extinction, although in that period of time the temperature rise was far more catastrophic and violent than today, because we will control this temperature, but life had to face sweltering temperatures for millions of years at the Permian-Triassic Boundary).
25. Make sure that in the 22nd century, a cult of cooling does not take over, which reduces CO2 levels to such an extent that we end up in a Frostpunk like Sudden Ice Age (or like the Great Oxygenation and subsequent Global glaciation).
26. Leave sufficient fossil fuels for our far off descendants, if they survive that long, that when Earth's carbon dioxide levels naturally start to fall after 250-500 million years, burning them can bring them back up. Among other things, preventing ice ages which may happen before that. In that sense, if all this happens, life would've achieved the homeostasis which was spoken about in the Gaia Hypothesis. Not to mention our newfound ability to deflect asteroids.
That's about all that I can think about at this moment, but I'm sure there could be other things too that I'm missing.
I hope y'all are happy, 'cause I indeed solved everything multilly. :D
27. Economic damage from Climate Change, I've assumed is 4.5% at 2 degrees Celsius and is hardcapped at 4.7-4.9%. The assumption being that that many more people on the Earth = more brains and hands to solve problems and that much more wealth and technology translates to greater resistance.
Of course, I may be wrong, but it doesn't matter, as here temperatures stop at +1.95 degrees Celsius.
28. Population decline will probably lead to an economic contraction some time in the mid-22nd century. And populations will probably rebound at some point after that, maybe, as those who have the highest fertility will be selected to pass on their genes, and such people tend to be the highly religious, expect societies to be highly religious or atleast pro-life after the mid to late 22nd century in terms of a majority. Or perhaps in the early 23rd century.
The Ultra-Orthodox in Israel still have 7-7.5 children and are slated to make up 30% of Israel's population by 2050, as birth rates decline in other groups, even the Orthodox (today 2.5-3.5).
Their birth rates are not so different from where they were in the 50s, when they used to have 8 children on average.
My exact numbers could be wrong, but they do have exceptional fertility, and so do the deeply faithful/highly religious in general.
In my view, this is probably the most realistic path to sub-two degrees.
It does not include Hydrogen, so this is not the most realistic, but it's as close to real as possible within the confines of this model.
The updated link is THIS. Here temperature rise is +1.99 degrees Celsius, but technically still below 2 degrees Celsius of temperature rise.
It involves no carbon tax.