R. Saravanan (sarava.net)

Professor & climate scientist at Texas A&M University. (@sarava.net on Author: Edu: @Princeton/@NOAA_GFDL, @IITKanpur

[R. Saravanan (sarava.net) @RSarava]

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!

[Rishika Pardikar @rishpardikar]

There are misleading articles in European media about India's stance on 1.5°C. Below is my report from COP30 about India's actual stance and the reasoning behind it. A climate scientist also lays out the nitty-gritty in the interview. https://t.co/v9a8Fc7q15

[R. Saravanan (sarava.net) @RSarava]

@NVallangi I read about that article too. It was shocking!

[R. Saravanan (sarava.net) @RSarava]

@PramathSinha @AshokaUniv @rishikesha @somakrc Congrats, Rishi!

[R. Saravanan (sarava.net) @RSarava]

@CColose @hausfath @RogerPielkeJr The link between GHG+aerosols and global T was never meant to apply on annual timescales. Simplistic statistical models of ENSO (which ignore different flavors of ENSO and other internal modes) are used to make the annual linkage. (Some even link it on monthly/daily timescales!)

[R. Saravanan (sarava.net) @RSarava]

@CColose @hausfath @RogerPielkeJr I guess the scientific point I'm trying to make is that it is very difficult to close the planetary heat budget on an annual timescale due to internal variability and poor knowledge of the 3-d oceanic state. ENSO is just one of many internal modes, albeit the dominant one.

[R. Saravanan (sarava.net) @RSarava]

@CColose @hausfath @RogerPielkeJr The cause of year-to-year global T variations is indeed not settled science, because it mixes GHG+aerosol effects with internal variability, including ENSO. Unfortunately, people don't wait until the next decade to post about long term trends in warming, as they perhaps should..

[R. Saravanan (sarava.net) @RSarava]

@noahqk I agree

[R. Saravanan (sarava.net) @RSarava]

@CColose @PaulRoundy1 @ArgonneForest @joelgombiner @jonbaker_ocean Also, predicting multidecadal AMOC evolution isn't just a boundary value problem like predicting global avg T. It's also an initial value problem sensitive to the 3D state of the deep ocean, possibly subject to the butterfly effect. As noted earlier, this state is poorly observed

[R. Saravanan (sarava.net) @RSarava]

@CColose @PaulRoundy1 @ArgonneForest @joelgombiner @jonbaker_ocean The atmospheric analogue of lo-res ocean models used for most hosing experiments would be models that don't resolve synoptic weather systems, the equivalent of oceanic baroclinic eddies. Expensive hi-res models suggest AMOC is quite sensitive to how these eddies are parameterized

[R. Saravanan (sarava.net) @RSarava]

@CColose @PaulRoundy1 @ArgonneForest @joelgombiner @jonbaker_ocean When I said it's difficult to predict, I meant we shouldn't be trying to predict it. I trust simple/intermediate models even less then full GCMs for AMOC prediction. There are other, more robust, reasons to motivate climate action than the "imminent collapse" of AMOC this century

[R. Saravanan (sarava.net) @RSarava]

@CColose @PaulRoundy1 @ArgonneForest @joelgombiner @jonbaker_ocean It's very difficult to predict the AMOC. Models don't even agree on its strength. The comprehensive IPCC-class models are coarse, with O(100km) grid. Ocean processes at much finer scales, such as convection, affect AMOC. IPCC projections don't indicate collapse before 2100, FWIW.

[R. Saravanan (sarava.net) @RSarava]

@sh_reya Sounds rather dystopian. I use AI to code complex projects. Parts of it I understand well (statistics, ...) and many other parts, I don't understand well (UI, CSS, ReactJS, ...). I could help an intern with parts that I understand but not with parts that I don't...

[R. Saravanan (sarava.net) @RSarava]

@atrembath @ClimateFramo Sharp planetary boundaries or tipping points at precise global temperature thresholds (such as 1.5C or 2C) are not supported by comprehensive climate model studies.

[R. Saravanan (sarava.net) @RSarava]

@atrembath Net-zero, as noted by @climateframo, was presented as the requirement for stabilizing warming based on carbon cycle modeling. It is approximate with a +/10% error around zero.

[R. Saravanan (sarava.net) @RSarava]

@noahqk If the upper classes in rich economies are unwilling to cut consumption (income/wealth taxes may not be enough to force them), the burden of an overall growth cap will presumably fall on the less well off, who are the majority even in the "rich economies"...

[R. Saravanan (sarava.net) @RSarava]

@noahqk When academics in rich economies propose growth caps and reduced consumption, I always wonder if they practice what they preach? Have they moved to a much smaller house, switched to a vegetarian diet, minimized flying and fly economy when they rarely do fly...