iiinova — where your digital self keeps evolving

R. Saravanan @sarava.net · 03/05/2026

An estimate from @hausfath.bsky.social posting on the other site:

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R. Saravanan @sarava.net · 16/04/2026

Reminds me of this: www.cnbc.com/2017/12/21/l...

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R. Saravanan @sarava.net · 30/03/2026

This is my second time implementing the Skylimit protocol. I implemented it 3 years ago for Mastodon under the name Mahoot, but didn't follow through (local archiving of posts was frowned upon, for example). You can find the old version here: github.com/mitotic/pinafore-mahoot#… 2/2

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R. Saravanan @sarava.net · 27/02/2026

Hmm... I was also working on a feature to curate my feed and search my timeline on Mastodon (github.com/mitotic/pina...) when that search-related incident happened. Now I'm building Skylimit, a curating web client for Bluesky (github.com/mitotic/skyl...). Will be talking about it at #ATmosphereConf

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R. Saravanan @sarava.net · 02/02/2026

E.g., this section of Sherwood et al (2020) appears to use spread in LGM estimates as the measure of uncertainty. That's similar to using spread in GCMs as a measure of uncertainty. In both cases, unquantified uncertainties lurk in the background. agupubs.onlinelibrary.wiley.com/doi/10.1029/...

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R. Saravanan @sarava.net · 22/01/2026

Howdy Aggies (and friends of Aggies)! The Texas A&M Department of Atmospheric Sciences will be marking the 60th anniversary of its establishment at the 7pm Tuesday (Jan. 27) reception during the AMS Annual Meeting in Hilton Americas-Houston. Come join us!

The Texas A&M Department of Atmospheric Sciences will be marking the 60th anniversary of its establishment at the 7pm Tuesday (Jan. 27) reception during the AMS Annual Meeting in Hilton Americas-Houston.

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R. Saravanan @sarava.net · 16/12/2025

Texas A&M University is hosting a workshop on "High and Ultra-high Resolution Modeling of the Earth System", April 13-15, 2026. Topics include: - Status of current high/ultra-high resolution earth system models - Applications and future directions Details here: sites.google.com/tamu.edu/tam...

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R. Saravanan @sarava.net · 11/12/2025

When it comes to geoengineering, or even other solutions to global warming/climate changes, my favorite maxim is this from the 1970s ads for Caterpillar company: There are no simple solutions. Only intelligent choices. People selling simple climate solutions are often deluding themselves and others.

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R. Saravanan @sarava.net · 17/11/2025

LLMs are indeed imprecise and make dumb arithmetic mistakes. But it looks like more rigorous AI/ML approaches (sometimes combined LLMs) seem to do much better at math x.com/deedydas/sta...

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R. Saravanan @sarava.net · 25/10/2025

I sympathize with your argument about research being important, but @climatebook.bsky.social makes a valid point about how entities that ignore the large risks and uncertainties of geoengineering misrepresent the research for profit. My attempt at a Trolley Problem illustration of the uncertainty:

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R. Saravanan @sarava.net · 23/09/2025

Here's another fantasy world that forms the basis for many geoengineering and tipping point discussions. (I also have a longer comment responding to the original substack post on geongineering: www.theclimatebrink.com/p/revisiting... )

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R. Saravanan @sarava.net · 01/09/2025

Current climate models, with non-eddy resolving oceans, don't simulate AMOC well. The evidence is there in plain sight in the main figure of last week's paper on AMOC collapse. Note the spread in strength of "current" AMOC which is larger than the "collapse" amount for some models! 1/

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R. Saravanan @sarava.net · 08/08/2025

Here's what I got just now–still wrong. (it seems to be stochastic; on a different device I got the right answer)

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R. Saravanan @sarava.net · 08/08/2025

How many times does the letter b appear in blueberry ChatGPT: The word blueberry has the letter b three times — positions 1, 5, and 6. How many PhDs does it take to count the letter b in blueberry ChatGPT: Realistically? Zero — any middle-schooler (or a spell-check) can handle it. Checked it myself:

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R. Saravanan @sarava.net · 29/07/2025

Here's a helpful illustration!

Tipping Points at World's End
1.5C, 2C, 2030, 2050

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R. Saravanan @sarava.net · 09/07/2025

From the 1908 book by Svante Arrhenius, who built the first (0-dimensional) climate model. As a Scandinavian, he thought that increasing carbonic acid (i.e., CO2) would lead to more "equable" climates and more abundant crops. P.63 of www.gutenberg.org/cache/epub/6...

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R. Saravanan @sarava.net · 02/07/2025

Since 1960s, number of MLB home runs per year has gone up from about 3000 to 4000+ due to many factors (assuming ~2000 games/yr). The global warming effect (58/yr) contributes to this trend, but is a fairly small part of the 1000/yr increase so far. See Fig 1a of journals.ametsoc.org/view/journal...

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R. Saravanan @sarava.net · 28/05/2025

I'll be speaking tomorrow, Thurs., May 29th, at 9:30AM Eastern Time in the Weather & Climate Livestream www.youtube.com/@wclivestream Topic: Using climate models to predict solar and wind power droughts, i.e., periods when it is Dark & Still (agupubs.onlinelibrary.wiley.com/doi/full/10....)

Dark Stillness: Predicting Solar and Wind Power Droughts, R. Saravanan, https://r.saravanan.us

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R. Saravanan @sarava.net · 28/05/2025

Some quick comments on your blog post+paper: Per Betteridge's Law of Headlines, the answer to the question posed in the paper title is NO, observationally constrained multidecadal projections are not predictions. As the plot below from the paper shows, emission scenario matters beyond 2040 or so. 1/

Predictive skill in the imperfect model world and prediction of global mean surface temperature evolution conditional on time series of annual global mean temperatures from version 5 of the UK Met Office Hadley Centre/Climatic Research Unit (HadCRUT) data set HadCRUT5. (B) historical ob- servations from 1901 to 2023, unconstrained cMiP6 projections, and future predictions. the left panel shows time series, with the predictions in color and unconstrained projections in gray, with their corresponding 5th to 95th percentile ranges shaded. the right panels display warming of the future periods with 20- and 50-year lead time, with mean changes shown as dots and 5th to 95th percentile ranges represented by error bars. the warming relative to the preindustrial period can be determined by applying an offset between 1994–2023 and 1851–1900, which is estimated to be approximately 0.95 [0.89, 1.02] °c based on the hadcRUt5 dataset.

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R. Saravanan @sarava.net · 22/05/2025

More one-upmanship today! Microsoft vs. ECMWF Aurora ML "weather" model (doesn't predict rain, though!) news.microsoft.com/source/featu...

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R. Saravanan @sarava.net · 16/05/2025

I know nothing of this topic, but I asked ChatGPT for you:

To cook pot barley in an Instant Pot (also called hulled barley, which retains more of the bran than pearled barley), follow these guidelines:

Instant Pot Cooking Time for Pot Barley
Pressure cook time: 20–25 minutes at High Pressure

Natural release: 15 minutes, then release any remaining pressure manually

Water-to-Barley Ratio
Use 2.5 to 3 cups of water per 1 cup of pot barley

Optional Additions
Add salt, broth, or aromatics (like bay leaf, garlic, or onion) for extra flavor.

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R. Saravanan @sarava.net · 09/05/2025

As I like to say, nobody actually lives in Global-average Land, although it is often featured in the media! Rather like Disney Land...

Illustration Global-Average Land, which looks like the Disney Land Magic Kingdom, with streets like Geoengineering Ave and signposts for Tipping Points

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R. Saravanan @sarava.net · 27/01/2025

Question motivated by recent trends in the CMIP6 Global SST plot in the post: Do we "know" the TCR range well enough to justify TCR screening?

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R. Saravanan @sarava.net · 21/01/2025

From the Texas State Climatologist report on extremes: The coldest temperature of the year has tended to increase since 1900. However, the time series is quite noisy and looking only at recent decades can be misleading. climatexas.tamu.edu/files/Climat...

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R. Saravanan @sarava.net · 20/01/2025

We also have a recent paper on PNW 2021-like simulated heatwaves in the near future: How Do Climate Model Resolution and Atmospheric Moisture Affect the Simulation of Unprecedented Extreme Events Like the 2021 Western North American Heat Wave? agupubs.onlinelibrary.wiley.com/doi/10.1029/...

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R. Saravanan @sarava.net · 15/01/2025

If you are attending #AMS2025, I am giving a talk today (Wed 1/15) at 2pm (Room 205) on: Is Global Mean Surface Temperature the best index of Global Warming? Here's the Conclusions slide of the talk:

CONCLUSIONS

El Niño does not generally cause heatwaves everywhere (unlike AGW)
Record annual high in GMST does not necessarily mean:
- a physical “tipping” threshold is crossed
- or that AGW is “accelerating”, i.e., faster than predicted by CMIP models
GMST statistically conflates long-term AGW with short-term natural modes (like ENSO, PDO, AMO, …) with different spatial patterns
- This can distort any economic impact analysis based on GMST
Better to use an index that isolates the signal of interest (AGW, AMOC, …)
- A spatial pattern approach, like LFCA, has some advantages over temporal smoothing (no edge effects, …)

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R. Saravanan @sarava.net · 09/12/2024

I'm presenting a quirky poster at #AGU2024 on Tuesday, 8:30-12:20 in the Poster Hall (GC210-0052). Drop by if interested. agu.confex.com/agu/agu24/me... The main argument is that GMST may not be the best index to describe global warming, esp. on short timescales. It may be a Sisyphean poster...

Image of Sisyphus rolling a boulder with the text "Don't use GMST to describe AGW"

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R. Saravanan @sarava.net · 07/12/2024

This figure is a bit misleading for representing asymptotic convergence because the Y axis is stretched. Here's a non-stretch but slightly older version of the figure that captures the convergence better:

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R. Saravanan @sarava.net · 05/12/2024

Another movie/model image:

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R. Saravanan @sarava.net · 05/12/2024

Human-caused climate change is worsening heat waves and extreme rainfall in Texas, but perhaps not worsening cold extremes. Here's a figure from the Texas state climatologist's report showing the general warming trend in the coldest temperature of the year climatexas.tamu.edu/files/Climat...

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R. Saravanan @sarava.net · 04/12/2024

You may be also interested in the next bit of the poster then: MODERN EQUIVALENT? “The CEO has no idea if climate risk assessments are any good. However, he needs them to satisfy Fed/Treasury/SEC mandates.”

MODERN EQUIVALENT?
“The CEO has no idea if climate risk assessments are any good. However, he needs them to satisfy Fed/Treasury/SEC mandates.”

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R. Saravanan @sarava.net · 04/12/2024

From my AGU2023 poster: A story told by Kenneth Arrow, 1972 Economics Nobel Laureate, about World War II long-range weather forecasts he was asked to produce: “The commanding general is well aware that the forecasts are no good,” he was told. “However, he needs them for planning purposes.”

Kenneth Arrow 1972 Economics Nobel Laureate:
While serving in the Army Air Forces during World War II, Arrow was tasked with producing long-range weather forecasts. He and his colleagues soon realized that the prevailing techniques were no more accurate than random guessing. His team brought this to the attention of his supervisors...
“The commanding general is well aware that the forecasts are no good,” he was told. “However, he needs them for planning purposes.”

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R. Saravanan @sarava.net · 16/11/2024

Global climate models (used to assess impacts) don't even agree on absolute global avg T to within +/- 1.0C. In data, we don't know the preindustrial baseline to within ~0.2C. it seems to be academic to worry about global avg T fluctuations of 0.2/0.3C. (fig: Palmer & Stevens, 2019; models in color)

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R. Saravanan @sarava.net · 26/10/2024

Here's a drawing I made to illustrate Deep Uncertainty

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R. Saravanan @sarava.net · 18/10/2024

Texas A&M University is hiring a tenure-track Assistant Professor in Atmospheric Sciences. Please apply by Nov. 1, if interested. More info and application at: apply.interfolio.com/153380

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R. Saravanan @sarava.net · 18/10/2024

Texas A&M University is hiring a tenure-track Assistant Professor in Atmospheric Sciences. Please apply by Nov. 1, if interested. More info and application at: apply.interfolio.com/153380

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R. Saravanan @sarava.net · 17/10/2024

Just look at the most common figures, like Fig 4.2 (WG1) that shows global surface temperature changes under different scenarios. Even under the high emission SSP5-8.5 scenario, now considered unlikely, the temperature changes gradually. There is spread among models, but no abrupt change before 2100

IPCC figure showing monotonically increasing global surface temperature projections for different scenarios

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R. Saravanan @sarava.net · 14/05/2024

Local warming is not driven by global avg temperature. It is driven by remote circulation changes (teleconnection) or local greenhouse gas increases. El Niño (left) and greenhouse gas warming (right) patterns are different, even though they both raise global avg temp. metamodel.blog/posts/big-ba...

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R. Saravanan @sarava.net · 01/05/2024

The increase in the number of Nature branded journals is stunning!

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R. Saravanan @sarava.net · 30/04/2024

This is fun! Responding to climate change is kind of like this:

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R. Saravanan @sarava.net · 18/04/2024

Here's a figure from a report that deals with local uncertainties in Upper Colorado River Basin precipitation wwa.colorado.edu/resources/co... (See Ch11, Fig11.16, p444) ECS directly affects the green portion, the scenario uncertainty, although some of it is perhaps in the blue (model error) as well

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R. Saravanan @sarava.net · 10/04/2024

Perhaps this book cover captures some of that:

Book cover for Douglas Adam's Restaurant at the End of the Universe

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R. Saravanan @sarava.net · 20/02/2024

Perhaps also of interest: Is the Gulf Stream responsible for Europe’s mild winters? (Seager et al., 2002) rmets.onlinelibrary.wiley.com/doi/10.1256/...

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R. Saravanan @sarava.net · 29/01/2024

If you are attending the AMS meeting #AMS2024 in Baltimore, I'm presenting a talk at 9:15am ET, Tues., Jan. 30 on "Understanding the Limits of Climate Prediction When Assessing Risk" (Forum on Climate Linked Economics) Location: Latrobe (1st Floor, Hilton Baltimore Inner Harbor)

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R. Saravanan @sarava.net · 29/01/2024

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R. Saravanan @sarava.net · 29/01/2024

If you are a former member/friend of Texas A&M Atmospheric Sciences deparment and are attending the AMS Conference in Baltimore, we are holding a reception 7-10pm, Tues., Jan 30 in the Pickersgill Rm, Hilton Baltimore Inner Harbor. Come and say hello to old acquaintances!

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R. Saravanan @sarava.net · 29/01/2024

If you are a former member/friend of Texas A&M Atmospheric Sciences (@tamu_atmo) and are attending the AMS Conference #AMS2024, we are holding a reception 7-10pm, Tues., Jan 30 in the Pickersgill Rm, Hilton Baltimore Inner Harbor. Come and say hello to old acquaintances!

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