On āPessimismā and āOptimismā about Climate Change; and on SRM as a āCheap Fixā
Letās imagine the most optimistic climate change scenario for a century from now, without going completely bonkers. To do that, letās first split up greenhouse gas emissions (COā-equivalent or āCOāeā) into non-residual and residual emissions. The latter are emissions that are difficult or impossible to (fully) eliminate due to technological or other limitations. In our scenario, non-residual emissions ā that is, emissions that we can actually reduce with current technology and without disastrous socio-economic impacts ā continue to grow a little bit for a while (as they do in reality), but the curve starts bending down soon (which is a...
Carbon-neutrality is dead.
So, now what?
After carbon-neutrality was declared an official goal in the 2015 Paris Agreement it became fashionable for governments and corporations to declare their intention to become carbon neutral by 2050 or soon thereafter. This was never more than an empty promise, however. The deadline was set far enough in the future to make immediate action unnecessary and few if any governments or corporations ever accepted a realistic plan to actually achieve carbon-neutrality. A decade later, they have largely given up pretense. Some have officially given up the goal; others have silently voided or discarded it. Of course, carbon-neutrality by 2050 was...
Predicting Global Warming for Dummies
Climate scientists use supercomputers and extremely complicated models to predict the future climate, but there is a shortcut that can be used to predict average global warming. The key to that shortcut is the following simple formula: $$ \Delta T_{anom.} = \frac {ECS \times ( C_{atm.} ā 280 )} {280} \: – \: \psi,$$ in which \(\Delta T_{anom.}\) is the average temperature anomaly (or average global warming), \(ECS\) is āEquilibrium Climate Sensitivityā, \(C_{atm.}\) is atmospheric carbon (in ppm COā equivalent), and \(\psi\) (from Greek Ļįæ¦ĻĪæĻ, meaning ācoldā) stands for various cooling effects. If you have the values of the variables...
Carbon-neutrality by 2050
(Originally published on December 15, 2020. First major revision on June 13, 2022. This is the second major version.) A few years after carbon-neutrality became an official goal in the Paris Agreement of 2015, one after the other, governments started to announce that their countries would be carbon-neutral by 2050 or a little bit later. Richer countries generally opted for 2050, while China and India, for example, aimed for 2060 and 2070, respectively. The promise of carbon-neutrality by 2050 (or 2060, or 2070) is a cheap promise, however, as the target is so far in the future that it doesnāt...
Rent, Profit, and Degrowth ā A Postscript to āCapitalism and Climate Collapseā
In Capitalism and Climate Collapse, I argued that catastrophic climate collapse cannot be avoided under capitalism because capitalism requires economic growth, economic growth requires energy growth, energy growth requires extensive burning of fossil fuels, and extensive burning of fossil fuels causes catastrophic climate collapse. To avoid collapse, we need to shrink the economy ā that is, degrowth ā to a sustainable level with respect to energy requirements, and then switch to a steady state economy to stay at that level. What exactly that sustainable level is is debatable, but regardless of whether itās closer to one third of current closer...
SotA-R-10: Combined Models 4 and 5 Suggest 62% Change of Exceeding 3Ā°C of Average Global Warming
(This is part 10 of the āStages of the Anthropocene, Revisitedā Series (SotA-R).) The previous episode in this series explained a few problems of the last iteration of the model used to better understand feedbacks between climate change and socio-political and economic circumstances (i.e. āModel 4ā). Additionally, in another recent post, I mentioned that the relation between atmospheric carbon and warming is probably better treated as linear, with time lag explaining the discrepancy between a linear equation and the current level of warming. Furthermore, that post also addressed the issue of tipping points (and other neglected feedbacks), leading to an...
The Probability of the End of Civilization in the 21st Century
Climate scientists have been calling recently for more research into warming scenarios of 3Ā°C and above because such scenarios are dangerously neglected. According to mainstream models such levels of warming are by no means impossible or even unlikely, and would have catastrophic effects. Luke Kemp and ten colleagues write: Could anthropogenic climate change result in worldwide societal collapse or even eventual human extinction? At present, this is a dangerously underexplored topic. Yet there are ample reasons to suspect that climate change could result in a global catastrophe. The answer to the question in this quote is obviously āyesā, but thatās...
SotA-R-9: Some Comments on Model 4 (and Another Error)
[(This is part 9 of the āStages of the Anthropocene, Revisitedā Series (SotA-R).) The latest iteration of the model I have been developing in this series in an attempt to predict how much carbon we are going to emit in stage 1 of the anthropocene predicted that weāll heat up the planet by about 3.3Ā°C (67% interval: 2.3~5.0Ā°C), and that this will imply (or involve) widespread famines, civil war, refugee crises, and societal collapse. Rather than take that prediction for granted, it seemed a better idea to compare this prediction with some other predictions, and to have a closer look...
SotA-R-8: Climate/Society Feedback Model 4 Predicts 3.7Ā°C of Average Global Warming
(This is part 8 of the āStages of the Anthropocene, Revisitedā Series (SotA-R).) (This post was updated on July 28.) ā Earlier this year I found a serious error in the equations I was using to calculate warming due to carbon emissions. As explained in March, this meant that the climate/society feedback models presented in the previous three episodes in this series were all wrong, and thus that I needed to patch up the latest iteration of those models. The result of that āpatching upā is model 4, which is mostly identical to model 3. The only differences are the...
SotA-R-7: Current Models Predict 4Ā°C of Global Warming
(This is part 7 of the āStages of the Anthropocene, Revisitedā Series (SotA-R).) Important Note (March 3, 2022) Due to a fundamental flaw in models 1, 2, and 3 in this series, the predictions for average global warming in this article are unreliable. Update (May 21, 2022) Model 4 fixes this problem and predicts +3.7Ā°C. Thereās no plausible peaceful path to carbon-neutrality. If thereās one key takeaway from my attempts to model carbon (COā-equivalent) emissions in stage 1 of the anthropocene, itās that. Oh, and thatās it will get hot, of course. Unpleasantly hot. This the fourth in a series...
SotA-R-6: Modeling Carbon Emissions ā New Results, and Thoughts on Further Models
(This is part 6 of the āStages of the Anthropocene, Revisitedā Series (SotA-R).) Important Note (March 3, 2022) Due to a fundamental flaw in models 1, 2, and 3 in this series, the predictions for average global warming in this article are unreliable. Update (May 21, 2022) Model 4 fixes this problem and predicts +3.7Ā°C. As mentioned in the section ālimitations and alternative approachesā of the previous episode in this series, there were a couple of things I wanted to change in the model (i.e. spreadsheet) used to simulate global carbon (COā-equivalent) emissions in stage 1 of the anthropocene. The...
SotA-R-5: Modeling Carbon Emissions in Stage 1 of the Anthropocene ā a First Attempt
(This is part 5 of the āStages of the Anthropocene, Revisitedā Series (SotA-R).) Important Note (March 3, 2022) Due to a fundamental flaw in models 1, 2, and 3 in this series, the predictions for average global warming in this article are unreliable. Update (May 21, 2022) Model 4 fixes this problem and predicts +3.7Ā°C. The aim of this series is a better prediction of the long-term prospects for human civilization (in the context of climate change) than the rather sketchy predictions made in Stages of the Anthropocene three years ago. The previous episodes in this series discussed some relavant...