Zeke Hausfather writes about climate science, warming data, emissions scenarios, and renewable energy, with charts.
HN commenters argue over its claims on RCP8.5, wildfire management, and solar, and cite its charts of warming trends.
> A primary hypothesized reason for the literally-off-the-charts heat of the past 15 months or so is that regulations that cleaned up the amount of sunlight-reflecting aerosols in container ship fuel was having the effect of letting more sunlight reach Earth; the idea is that the aerosols had previously been limiting the amount of global warming that would have shown up earlier.
I see this repeated a lot on HN, but it appears to be incorrect. It seems that climate scientists are aware of aerosols and can model them, but 2023 is still a baffling outlier.
> These include continued accumulation of greenhouse gases, the evolution of El Niña and La Niña, and the 11-year solar cycle. It also includes two new factors that emerged during the decade: the 2022 eruption of the Hunga Tonga volcano and the 2020 phase-out of sulphur in marine fuels. Both of these are estimated to have relatively modest effects at present – less than 0.05C each – but with large scientific uncertainties.
> Similarly, the phase-out of sulphur in marine fuels occurred in 2020. If it had a large climate impact, it would show up in 2021 and 2022 rather than suddenly affecting the record in 2023. While it definitely has had a climate impact – alongside the broader reduction in aerosol emissions over the past three decades – the timing suggests that its likely not the primary driver of 2023 extremes.
https://www.theclimatebrink.com/p/2023s-unexpected-and-unexplained
> You also mention the time spent waiting for nuclear to come online but fail to consider that PV has consistently failed to reduce fossil fuel usage (in absolute or percentage numbers) even as the market share of it has skyrocketed.
You should look at flows rather than stocks.
> However, stocks are a lagging indicator. Stocks follow flows; the car fleet follows car sales. Flows are the leading indicator. In the early stages of a transition, flows present a very different story to stocks. For instance, it is frequently noted that fossil fuels account for over 80 percent of global primary energy and this number hasn’t budged meaningfully for decades.
> Rarely mentioned is the fact that renewables have been taking an increasing share of the growth in energy supply, and all of the growth in 2019-21. Moving the focus from stocks to flows moves the conclusion from no change to radical change. Concentrating on the size of the fossil fuel system today is like focusing on the large number of horses in 1900 — it was as good a guide then as it is now.
https://www.theclimatebrink.com/cp/138702709
For example, China's fossil use is set for structural decline since renewables more than make for the required grid expansions.
https://www.theguardian.com/business/2023/nov/13/chinas-carbon-emissions-set-for-structural-decline-from-next-year
> have always been considered by many in the climate science community to be underestimating climate change.
This is exactly wrong as it relates to RCP 8.5. A number of research papers came out basically showing how 8.5 was completely implausible, and it was only after these papers were widely cited and reached consensus did the IPCC retire 8.5.
This article by some of the original authors of one of those papers explains the situation well: https://www.theclimatebrink.com/p/on-the-death-of-rcp85 . If you actually read their linked research paper, I don't think any unbiased observer could think 8.5 is plausible anymore (and, in fairness, 8.5 was always proposed as a worst case scenario, not a "business as usual scenario", as that climatebrink article explains very well).
Former CEO of AXA, a major French insurer, famously announced that a world at +4°C would be "uninsurrable" [1].
That was 10 years ago.
It's true that most predictions about climate are wrong - most of the time, they're optimistic. (Not always, fortunately [2])
[1] https://www.leparisien.fr/economie/business/special-cop21-un-monde-plus-chaud-de-4-degres-sera-impossible-a-assurer-selon-le-pdg-d-axa-30-11-2015-5326047.php
[2] https://www.theclimatebrink.com/p/emissions-are-no-longer-following
"Unfortunately, while their radiative forcing estimate is well within the range of others in the literature, their calculation of the resulting warming relies on an overly simplified model that results in a substantial overstating of current warming impacts.", https://www.theclimatebrink.com/p/a-problematic-estimate-of-warming
The conclusions of this paper are being disputed. Read more about that at the page linked above.
Representing that as a "climate spiral" would make it unnecessary to adjust for the seasons, and the original data could be used instead of a statistical view. It makes it easy for anyone to see the trend.
- https://en.wikipedia.org/wiki/Climate_spiral
- https://www.theclimatebrink.com/p/visualizing-daily-global-temperature
- https://www.climate-lab-book.ac.uk/spirals/