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 doesn’t...
Some Further Comments on Climate Sensitivity and Warming Estimates
While preparing an update of Carbon-Neutrality by 2050 (by far the most accessed page in this blog), I had another look at (equilibrium) climate sensitivity (ECS), a topic about which a wrote a few times before. ECS is the expected global temperature anomaly (i.e., the expected global average of warming) at twice the pre-industrial level of greenhouse gases (mainly CO₂) in the atmosphere (i.e., 560ppm, as “pre-industrial” is set at 280ppm). The currently most widely accepted estimate of ECS is that by Steve Sherwood and colleagues, who suggest average warming of 3.1°C (median; 66% uncertainty range: 2.6~3.9°C; 95%: 2.3~4.7°C). However,...
SotA-R-10: Combined Models 4 and 5 Suggest 62% Change of Exceeding 3°C of Average Global Warming
(This is part 9 of the “Stages of the Anthropocene, Revisited” 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. “Model 4”). 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...
Tipping Points, Permafrost Thaw, and “Fast” Reduction
Last Thursday a new analysis of the main “tipping elements” in the Earth system was published in Science., The paper and its supplementary materials provide data on likely thresholds and effects of all the main tipping elements that have been discussed in the literature of the past two decades. Furthermore, the supplementary materials also discuss a number of other feedback effects that have been suggested as tipping elements before, but that turn out to be too gradual to be properly classified as such. These effects are at least as important, however, and tend not to be (fully) included in common...
A Theory of Disaster-Driven Societal Collapse and How to Prevent It
(abstract) — One of the effects of climate change is an increase in extreme weather and natural disasters. Unless CO₂ emissions are significantly reduced very soon, it is inevitable that the effects of disaster will exceed many (and ultimately all) societies’ mitigation capacity. Compounding unmitigated disaster effects will slowly but surely push a society towards collapse. Because no part of the planet is safe from the increase in natural disaster intensity and because some of the effects of disasters – such as refugees and economic decline – spill over boundaries, this will eventually lead to global societal collapse. Furthermore, just...
On the Fragility of Civilization
(This is part 2 in the No Time for Utopia series.) Doom has always been a major attraction for some, perhaps even many people. There are whole subgenres of extreme (heavy) metal built on the aesthetics of death, doom, and decay. But “doom” in the form of extreme pessimism about the (near) future is also increasingly common in discussions about climate change and its effects. In Stages of the Anthropocene I tried to look into the more distant future. Whether what I found is an example of “doom” in this sense is debatable – at least I didn’t predict human...
No Time for Utopia
Most political thought is “ideal theory”: its arguments are based on an idealized world in which important aspects of reality are abstracted away. Abstraction isn’t necessarily a bad thing – in the contrary, it is often necessary in science – but it isn’t self-evident that the results of abstractions and idealizations are (always) applicable to the real world, and if theory doesn’t descend from the ideal world to reality it turns into an intellectual game without practical relevance; or worse, as the case of neoclassical economics illustrates. In that case abstraction and idealization resulted in a “theory” that explains nothing,...