Jessica Tierney
@leafwax.bsky.social
1.5K followers 130 following 64 posts
Climate scientist living in the Sonoran Desert. Analyzer of leaf waxes to learn about past climate change. Professor at the University of Arizona. I also like birds, nature, pets🦉🌿🐕 | Opinions are mine, not those of my employer
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leafwax.bsky.social
I do love Reddit for so many reasons. Thanks for accepting me bros!
leafwax.bsky.social
A proposed Amazon data center in Tucson (“Project Blue”, FFS) that would have sapped power and water from the city has been REJECTED thanks to amazing community solidarity. The people of the desert have spoken and won ✊🌵🏜️
Reposted by Jessica Tierney
drkatemarvel.bsky.social
why does coal use she/her pronouns
mims.bsky.social
struggling with an analogy here but imagine NASA posting a meme about how excited they are to return aviation to the pre-jet age
u.s. department of energy post on x praising coal:

"She's an icon
She's a legend
And she is the moment

[sparkly picture of coal]
leafwax.bsky.social
Here's some lovely artwork from the no desert data center (www.instagram.com/no_desert_da...) coalition that captures our feelings ⛈️

It would be great if a national news outlet picked up this story - its a type case for something that is increasingly an issue in the West. /fin
leafwax.bsky.social
AI data centers are just the latest put your junk in the desert thing. But we as desert dwellers don't need to stand for it. Why would we repeat the past's mistakes? All for an AI response for a search (that sometimes you didn't ask for and don't really need!).
leafwax.bsky.social
There is a long history in the American West of putting our country's junk in the desert. c.f. a large portion of the State of Nevada (incl. the nuclear test range) and Dugway Proving Ground in Utah, where chemical and biological weapons were tested en.wikipedia.org/wiki/Dugway_...
Dugway Proving Ground - Wikipedia
en.wikipedia.org
leafwax.bsky.social
It seems to me that data centers in the desert is the new "growing alfalfa in the desert." It makes more sense to put these in places with more water...but land is cheap in the desert and local cities might be more amenable to the deal...
leafwax.bsky.social
Economically the boost of the data center would be the construction jobs, and there is no denying that, hence for trade unions this is a really good thing. But in the long-term, there are almost no people working at places like this. www.kold.com/2025/07/24/e...
Emotions run high in public meeting held by City of Tucson over Project Blue
The project has drawn a lot of attention around Pima County
www.kold.com
leafwax.bsky.social
The city claims the River won't be affected, but it's hard to imagine how, since water diverted to the data center means less outflow on the river at one of the flow stations no matter where it occurs. Prof. Michael Bogan at @uarizona.bsky.social crunched the math drive.google.com/file/d/1sSAp...
ProjectBlue_SantaCruzImpacts_11Jul2025.pdf
drive.google.com
leafwax.bsky.social
Reclaimed water is used to restore the Santa Cruz River, which was in the early 20th century an actual flowing river but due to ground water pumping no longer flows on its own. But thanks to reclaimed water we now have these beautiful riparian areas coming back www.azcentral.com/story/news/l...
Proposed data center raises concerns about drying up this Arizona river
The Santa Cruz River, dried up and polluted, came back to life recently, sustained by highly treated wastewater from two water reclamation facilities.
www.azcentral.com
leafwax.bsky.social
The water would rely on extending Tucson's reclaimed water system to the build to supply an estimated 0.8 million gallons per day (data centers in Phoenix use more than this). The problem is, reclaimed water demand is already very high in the city, and...
leafwax.bsky.social
As far as power goes, the project is estimated to require 400-600 MW at full build. It's not clear yet how TEP our power supplier will meet that. Current peak energy demand is 2400 MW so this is non-trivial. It could involve keeping coal-fired plants up and running past their expiration date.
leafwax.bsky.social
"Project Blue" is some (read: greenwashing) name for a data center that would be roughly the size of downtown Tucson, eat power and water, and provide only 180 jobs. For perspective, my department alone at the @uarizona.bsky.social employs about 130 people within 3-4 floors of a single building.
leafwax.bsky.social
This summer Tucsonians started to hear about something called "Project Blue", a proposal to build data centers on our outskirts. The city officials signed a NDA to not disclose the company❗but thanks to @azluminaria.org the company was outed this week as Amazon 🤡 azluminaria.org/2025/07/21/a...
Amazon Web Services is company behind Tucson’s Project Blue, according to 2023 county memo - AZ Luminaria
Amazon Web Services is revealed to be the company behind the Project Blue data center proposed for Tucson.
azluminaria.org
leafwax.bsky.social
This @wired.com article is extremely timely for those of us in Tucson, Arizona, as we face the possibility of Amazon Web Services building a huge data center at our outskirts. Energy and water use for AI data centers are non-trivial. Read my thread below if you want to hear about our local story ⬇️
wired.com
WIRED @wired.com · Jul 24
AI this, AI that, what about how much energy AI actually uses?

“It blows my mind that you can buy a car and know how many miles per gallon it consumes, yet we use all these AI tools every day and we have absolutely no efficiency metrics, emissions factors, nothing." From the experts:
How Much Energy Does AI Use? The People Who Know Aren’t Saying
A growing body of research attempts to put a number on energy use and AI—even as the companies behind the most popular models keep their carbon emissions a secret.
www.wired.com
leafwax.bsky.social
Several Fellows I talked to have decided to leave the US and seek science positions in Europe, citing the lack of positions here and negative attitude towards science 😞 Brain drain is a real thing that will have lasting impacts on US scientific strength.
leafwax.bsky.social
Also, while temporary, the furlough caused a lot of stress for the Fellows, who scrambled to file for unemployment or get temporary positions since no one knew when it would end.
leafwax.bsky.social
Update on the NOAA Fellows situation: as of late last week the furlough has been lifted (phew!). However, there are no new Fellows this year, and we still don't know the future of this program.
leafwax.bsky.social
As of today, all current NOAA Climate and Global Change postdoctoral fellows have been furloughed due to the Dept of Commerce not releasing the funding for the program. In addition no new Fellows were awarded this year. cpaess.ucar.edu/cgc
NOAA Climate & Global Change (C&GC) Postdoctoral Program | Cooperative Programs for the Advancement of Earth System ScienceNOAA Climate & Global Change (C&GC) Postdoctoral Program | Cooperative Progra...
cpaess.ucar.edu
leafwax.bsky.social
✨Paper #2 has just been published @weareagc.bsky.social ✨ And it is about hopanoids!! Thank you @climategordon.bsky.social for trusting a brand new journal with your research. AGC is 💎 open access: free to publish and free to read 🙌 Geochemists, come publish with us! journals.uu.se/AGC/article/...
Hopanoid distributions differ in mineral soils and peat: a re-evaluation of hopane-based pH proxies | Advances in Geochemistry and Cosmochemistry
Advances in Geochemistry and Cosmochemistry, ISSN 2977-1994 | CC BY 4.0
journals.uu.se
Reposted by Jessica Tierney
rdzombak.bsky.social
The Trump administration's proposed budget would slash NOAA's climate research funds.

It still has to pass Congress, but it's already affecting scientists. A program supporting promising new climate scientists furloughed its current cohort and canceled 2025 awards.

www.nytimes.com/2025/07/09/c...
Recipients of a U.S. Climate Science Fellowship Are Put on Unpaid Leave
www.nytimes.com
leafwax.bsky.social
So bummed you are leaving - but it's probably a good choice