Ken Caldeira

Senior scientist (@CarnegieScience, Gates Ventures).

[Ken Caldeira @KenCaldeira]

Please follow me on Bluesky

https://t.co/2DzekQh7sq

[David Keith @DKeithClimate]

Ken @KenCaldeira, Bala Govindasamy, B. B. Cael, and me are running an effort to assess climate hazards that might be caused by stratospheric aerosol injection.

We want your input: https://t.co/vWglb0N6aV.
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[David Keith @DKeithClimate]

New paper: "Solar Geoengineering: History, Methods, Governance, Prospects" by @parson_ted & me in Annual Reviews.

Full text at: https://t.co/tMzbu7RZrW

I am particularly proud of this paper. This thread provides some highlights:
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[Ken Caldeira @KenCaldeira]

@ciphergoth That is not too far from my job description.

[Ken Caldeira @KenCaldeira]

@tlarson95425 At this point the most valuable thing would be to fill out this form describing what you think could go wrong, from a physical science perspective, with a solar "well-designed, well-intentioned" solar geoengineering deployment.

https://t.co/7JkIgYBYgC

[Ken Caldeira @KenCaldeira]

We are organizing a meeting on what could go wrong, from a physical science perspective, if stratospheric aerosol geoengineering were ever deployed.

If you have suggestions for who to invite to such a meeting, please email or DM me (or mention in a reply).

[Ken Caldeira @KenCaldeira]

Does anybody want to model and evaluate out-there geophysical ideas as a postdoc in my group on the Stanford campus?

Can vertical ocean mixing weaken hurricanes? Could a fleet of kites shift the jet streams and storm tracks?

https://t.co/Zv6QiD5fFC
https://t.co/RSCk5fwExZ

[Ken Caldeira @KenCaldeira]

@Revkin https://t.co/EChNa3x8zk

[Ken Caldeira @KenCaldeira]

@jacopogio @JesseJenkins The question of the relative value of an emission occurring at one time and an emission occurring at a different time is complicated.

The question of the relative value of an emission occurring at one time and a withdrawal occurring at the same time is simple.

[Ken Caldeira @KenCaldeira]

It is obvious that a ton of CO2 emissions and a simultaneous ton of atmospheric CO2 removal have equal and opposite effects.

Let's stop making things seem more complicated than they are.

[Zeke Hausfather @hausfath]

Theres been a bit of confusion lately around how the climate system response to carbon dioxide removal. While there are complexities, under realistic assumptions a ton of removal is still equal and opposite in its effects to a ton of emissions.

A thread: 1/x

[Ken Caldeira @KenCaldeira]

@xiaowang1984 We looked at resource / demand relationships only, and did not consider component failure.

https://t.co/soltzIJGW0

[Ken Caldeira @KenCaldeira]

Reliable wind-and-solar-based electricity systems need to be designed taking more years of weather data into account than is now common practice, because weather is quite variable even at continental scale.

Paper: https://t.co/20VXSMl6VR
Research Brief: https://t.co/CxHeJBeAFs

[Ken Caldeira @KenCaldeira]

""If anything, these results should increase our sense of collective efficacy — which is sorely needed," @KHayhoe

Climate policy and tech development is doing something good.

Not enough, but in the right direction.

https://t.co/RRtZCAKll6

[Ken Caldeira @KenCaldeira]

Are the recent hot years a sign of accelerating warming, or anomalous increases imposed on a general warming trend?

Projections of warming under current policy suggest the most rapid warming is behind us (but most of the climate damage in front of us).

https://t.co/eSZYLKggtN
https://t.co/RhlCPHyP3Z

[Ken Caldeira @KenCaldeira]

@HenzeTimon Yes.

We didn't attempt attribution in 2008, because we were looking at observations only.

Attribution involves comparing with a counterfactual, usually provided by model simulations.

In any case, identification and attribution would be more certain today

[Ken Caldeira @KenCaldeira]

Everything old is new again.

Observed poleqard shift in the jet streams.
https://t.co/cY7ZV0Smut

[James Dinneen @jamesNESW]

Parts of Earth's jet stream have shifted toward the poles over the past several decades, likely in response to climate change. This was long forecast to happen, but has only now "emerged from the noise" says Thomas Keel @UCLgeography. New in @NewScientist:
https://t.co/nQeEQvXC0V

[James Dinneen @jamesNESW]

Parts of Earth's jet stream have shifted toward the poles over the past several decades, likely in response to climate change. This was long forecast to happen, but has only now "emerged from the noise" says Thomas Keel @UCLgeography. New in @NewScientist:
https://t.co/nQeEQvXC0V

[Ken Caldeira @KenCaldeira]

@PetersJVecrumba @AmoneyResists @nytimes https://t.co/kVZfpDfeZt

[Ken Caldeira @KenCaldeira]

@PetersJVecrumba @AmoneyResists @nytimes @PetersJVecrumba Reported by whom? Where?

[Ken Caldeira @KenCaldeira]

@politixdude @nytimes More likely that the headline writer is a MAGA Republican than a summer intern.

[Ken Caldeira @KenCaldeira]

@ciphergoth I assume they are saying anything they think they need to say to win.

Perhaps, this is a rare case in which the ends justify the means.

[Vinod Khosla @vkhosla]

Hard for me to support someone with no values, lies, cheats, rapes, demeans women, hates immigrants like me. He may cut my taxes or reduce some regulation but that is no reason to accept depravity in his personal values. Do you want President who will set back climate by a decade in his first year? Do you want his example for your kids as values?