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Marcus C Sarofim

@marcusmarcusrc.bsky.social
625 followers 75 following 169 posts

Climate scientist, ex-EPA. Writing climate science & policy at The Saraph Report. Saraph, my name's root, means fire, which is appropriate for climate work. Interested in books, food, and contra dancing when not obsessing over carbon.

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Marcus C Sarofim @marcusmarcusrc.bsky.social · 02/10/2026
I made a thing (with Claude's help): it is a tool to analyze all the responses to the vehicle Endangerment rescission (98% opposed). Please like the substack and repost on bsky so that it gets visibility for all the people working on comments on the power plant Endangerment rescission.
thesaraphreport.substack.com
A Tale of Two Endangerment Rescissions
And a webtool for digging into vehicle Endangerment comments
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 02/10/2026
See retractionwatch.com/2026/10/02/p...: though I think I was repeating someone else's (accurate) assessment of the paper as a hot mess rather than it being my own original take on the paper.
retractionwatch.com
‘Hot mess’ paper questioning CO2 and climate change gets retracted
The paper refers to air temperature data as “obtained by NASA from satellites” and claims the main areas of warming depicted in this figure do “not fit in with the main industrial…
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 23/09/2026
Full decision analysis could also take into account cost/ton, co-benefits (co-emitted pollutants, ocean acidification, methane-derived ozone, etc.), and amount available to abate. 2/2
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 23/09/2026
I've never liked the framing that a short lifetime means a better target. Given two gases with equal radiative efficiency and all else equal, the longer-lived one should be the more important target. 1/2
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 23/09/2026
Also, methane's reaction in the atmosphere produces ozone, which has direct effects on health & ecosystems in addition to its climate-mediated effects (e.g., see agupubs.onlinelibrary.wiley.com/doi/full/10.... and work by Jason West, Arene Fiore, Drew Shindell, and more)
agupubs.onlinelibrary.wiley.com
The Social Cost of Ozone‐Related Mortality Impacts From Methane Emissions
Increases in mortality attributable to ozone produced from methane are not currently considered in the government's social cost of methane Ozone from a 2020 methane emissions pulse results in 760...
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 22/09/2026
Nice to see my substack get linked from the NY times (click "surprises"): www.nytimes.com/2026/09/22/o...
nytimes.com
Opinion | Climate Catastrophe Is Still on the Table
Harrowing temperature increases remain unnervingly possible.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 22/09/2026
And yes, conspicuous consumption is a poorly defined concept that usually means “more than what I do”
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 22/09/2026
My rules: avoid conspicuous consumption, lobby for low carbon alternatives for most activities. Otherwise you get into arguments about how many weddings and conferences a year are acceptable to fly to, exactly how many car miles is equal to a round trip cross country flight (3000?), etc
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Reposted by Marcus C Sarofim
Bob Kopp @bobkopp.net · 22/09/2026
NEW PAPER: In a new paper, jointly published in @agu.org Earth's Future & @ametsoc.org BAMS, and co-led by Melissa Kenney, @costasamaras.com and me, 175 authors outline priorities to guide the future of scientific assessments of climate change in the United States. 🧵
doi.org
Research Priorities for Robust Climate Assessments in the United States
A network of climate assessments plays a critical role in synthesizing the state of science to support evidence-based decision-making To support future U.S. and sub-national climate assessments, ...
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 22/09/2026
a) I recognize that I have flying privilege. b) academics tend to have moved far from home, creating more incentive for travel to see friends and family (plus work travel). c) I am curious about how many of that 50% take long road trips which might be flight-equivalent in terms of CO2 emissions.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 22/09/2026
I don't own a car, I eat veggie forward (though not vegetarian), I live in a small apartment, I train rather than fly for <8 hour trips (I have taken 3 plane trips this year). But I also think that self-deprivation might actually hurt when convincing people to get behind policy & system change.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 21/09/2026
Today it clicked that one of my favorite SF authors is also a climate person! (see my selection of 10 F&SF book recommendations, with Memory Called Empire as one of them: thesaraphreport.substack.com/p/f-and-sf-r...). Sadly, I will not be at climate week...
thesaraphreport.substack.com
F&SF Recommendations, and Cli-Fi Reviews
What to read for fun, what to read if you want climate in your fiction.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 17/09/2026
Thank you for taking down bad science with a good helping of humor!
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 16/09/2026
Hopkins gave me their 2026 Excellence in Teaching award for Climate Change Policy Analysis, an evening course I've taught on and off for 8 years, and wrote up a faculty profile to go with it. I appreciate the recognition, but the real reward is working with amazing students (sorry for the schmaltz)
advanced.jhu.edu
Marcus Sarofim: Fueling a Passion for Climate Science
Marcus Sarofim brings decades of experience to the Energy Policy and Climate program with deep expertise and a hopeful outlook.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 16/09/2026
my initial analysis on the proposal suggests that in any sane world, it would go down in flames in court. Sadly… thesaraphreport.substack.com/p/copy-paste...
thesaraphreport.substack.com
Copy, Paste, Rescind.
My first look at the power plant rescission: aka, I read 162 pages so you don’t have to.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 16/09/2026
Yes, one would think, but... this administration and this Supreme Court can be pretty brazen in ignoring the obvious.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 16/09/2026
EPA's new power plant rescission argues that the "air pollution" Congress addressed in 1970 didn't include climate. It quotes Senator Muskie's 1970 floor statement twice while skipping the sentence where he warns of "irreversible atmospheric and climatic changes." My first read of all 162 pages.
thesaraphreport.substack.com
Copy, Paste, Rescind.
My first look at the power plant rescission: aka, I read 162 pages so you don’t have to.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 15/09/2026
Thank you! I’d forgotten about that
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 14/09/2026
The US has failed to submit greenhouse gas inventories to the UNFCCC for two years running, unlike the other 42 Annex I Parties. New post on why emission inventories matter and who is producing the US numbers now that the EPA isn't. thesaraphreport.substack.com/p/lecture-3-...
thesaraphreport.substack.com
Lecture 3: The Carbon Economy, Part I: The United States
Why is measuring emissions so important?
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 12/09/2026
The Trump Administration hates public comments, so keep doing it! I highlight coal ash, ship pollution discharge, roadless areas, and H-1B visa fees as comment opportunities for this month. thesaraphreport.substack.com/p/public-com...
thesaraphreport.substack.com
Public Comments Scare the Trump Administration
Six more proposals to submit short comments on
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 09/09/2026
My mantra: CDR infrastructure has to match the scale of the fossil industry that made the CO2 in the first place. So reduce emissions first, and if you have to, some BECCS (bio energy with CCS) to compensate for air travel and other hard to reduce sources.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 09/09/2026
I would like a per capita version of this map (100 votes in North Dakota is worth a lot more than in Texas). I talk about per capita maps in a post that is also about COVID: thesaraphreport.substack.com/p/covid-part...
thesaraphreport.substack.com
COVID Part 2, or "More evidence for MAGA lethality"
Also Part 2 of my new series, "Context matters for data"
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 09/09/2026
I had missed Sea Ice Today - glad to see it return!
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Reposted by Marcus C Sarofim
Climate.us @climate.us · 09/09/2026
Sea Ice Today is back! For nearly two decades, scientists at the National Snow and Ice Data Center, or NSIDC, have helped people understand what is happening to sea ice in the Arctic and around Antarctica. Its monthly science analyses were paused last fall. buff.ly/e20zCU6
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 04/09/2026
See my substack at thesaraphreport.substack.com/p/the-rcp85-... and Andy Dessler’s at www.theclimatebrink.com/p/the-worst-...
thesaraphreport.substack.com
The RCP8.5 Obsession Continues
The Trump Administration Tries to Monkey With NCA5
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 02/09/2026
Every four years, the US is supposed to release an assessment about climate change. We last did that in 2023 ("NCA5"). Now the Trump administration wants to slap a warning sticker onto it because they don't like one of the scenarios used in the report. It is inherently a pretty wonky topic...
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 02/09/2026
The Trump Administration is trying to "amend" NCA5. That's ridiculous. I explain why in my post. thesaraphreport.substack.com/p/the-rcp85-...
thesaraphreport.substack.com
The RCP8.5 Obsession Continues
The Trump Administration Tries to Monkey With NCA5
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 01/09/2026
I recommend Hannah Ritchie's "Not the End of the World" for good analysis that doesn't downplay challenges but shows these positive trends (see my reviews at substack.com/home/post/p-...)
substack.com
The Optimism Shelf
Three climate books worth reading
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 26/08/2026
Recently Americans seem to be choosing leaders who are neither good nor smart. (Also, I have loved the Harvey quote ever since playing Dr Chumley in 8th grade)
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 26/08/2026
DAC would need to be at the same scale of fossil fuel infrastructure to cancel it out. Easier not to emit in the first place! 2nd easiest is to condense at smokestacks (CCS or BECCS)
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 24/08/2026
I think a problem is that the echo chambers many of us live in are potentially being influenced by paid actors and Russians. But it probably isn't useful to tell your friend that you suspect their extreme position has been influenced by nefarious agents.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 23/08/2026
I've written some sf & fantasy book recommendations! (two are climate related to be on theme with the rest of my substack) thesaraphreport.substack.com/p/f-and-sf-r...
thesaraphreport.substack.com
F&SF Recommendations, and Cli-Fi Reviews
What to read for fun, what to read if you want climate in your fiction.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 19/08/2026
Lecture 2 is an overview of how economics and the environment interact. I also made a widget to explore the Coase Theorem - please play with it and give me feedback! thesaraphreport.substack.com/p/lecture-2-...
thesaraphreport.substack.com
Lecture 2: The Economy and the Environment
How economists frame the pollution problem
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 14/08/2026
Yet another chance for comment, this time on NSF guidance that is trying to create a backdoor to the horrible OMB rule from earlier this summer. thesaraphreport.substack.com/p/changes-in...
thesaraphreport.substack.com
Changes in Priorities
NSF wants the same ability to terminate grants that a federal court just rejected. Comments are due August 24th.
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 12/08/2026
This is the first post in my class lecture series: thesaraphreport.substack.com/p/lecture-1-...
thesaraphreport.substack.com
Lecture 1: Introduction
The first post in a Climate Change Policy Analysis series based on my Johns Hopkins class
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 12/08/2026
Climate brink dropped another quality post on wildfires : substack.com/@thesaraphre...
substack.com
Marcus C Sarofim (@thesaraphreport)
The effects of climate on wildfires is becoming more and more obvious. The linkage between climate, wildfire smoke, and human health is likely to be one of the larger contributors to the monetized imp...
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 09/08/2026
Also see Westerling and Bryant (2006): escholarship.org/uc/item/49v0.... But it is a hard problem: you need the fuel (vegetation models), good precip models for growing and then drying out the vegetation, the fire weather (winds and temperatures), the atmospheric chemistry, and so forth...
escholarship.org
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 09/08/2026
And Neumann et al. is included in the FrEDI model (not quite an IAM, but can be used by IAMs, see Yuan et al. 2026: www.worldscientific.com/doi/abs/10.1... )
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 09/08/2026
And before Qiu et al., Neumann et al. (2021) estimated US impacts of increased wildfire smoke due to climate... but only included western wildfires. The exclusion of Canadian wildfires has become an ever-more obvious omission... iopscience.iop.org/article/10.1...
iopscience.iop.org
Estimating PM2.5-related premature mortality and morbidity associated with future wildfire emissions in the western US
Estimating PM2.5-related premature mortality and morbidity associated with future wildfire emissions in the western US, Neumann, James E, Amend, Meredith, Anenberg, Susan, Kinney, Patrick L, Sarofim, Marcus, Martinich, Jeremy, Lukens, Julia, Xu, Jun-Wei, Roman, Henry
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 09/08/2026
I recommend these three high quality books on climate and the environment that should give you cause for optimism: thesaraphreport.substack.com/p/the-optimi...
thesaraphreport.substack.com
The Optimism Shelf
Three climate books worth reading
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 03/08/2026
My analysis of the data replicated others showing that R counties had higher mortality than D counties... but as far as I know, I'm the only one who highlighted that counties in R states were worse off than counties with equal vote shares in D states: substack.com/home/post/p-...
substack.com
COVID Part 2, or "More evidence for MAGA lethality"
Also Part 2 of my new series, "Context matters for data"
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Reposted by Marcus C Sarofim
Alt National Park Service @altnps.bsky.social · 30/07/2026
Meanwhile, the United States has already seen more than 4 million acres burn in 2026, with over 42,000 wildfires reported nationwide. #SaveUSFS
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 29/07/2026
I’ve never been to Climate Week NYC: please tell me why I should or shouldn’t go this year
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Reposted by Marcus C Sarofim
Kate Marvel @drkatemarvel.bsky.social · 29/07/2026
Fires depend on: ♨️ Weather ⚡ Ignition 🍂 Fuel 🧯 Suppression In North America: ♨️ Climate change = hotter and drier ⚡Ignition = no real change 🍂 Fire deficit = more fuel 🧯Warmer nights = suppression is hard What should we do? 📉 Cut emissions ✅ 🔥 Controlled burns ✅ 🍁 Rake more? ❌ 🇨🇦 Be mean to Canada ❌
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 29/07/2026
Trump’s cut rate contractors apparently drove over and broke the recently renovated German American friendship memorial
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 28/07/2026
Today's post looks at Trump's push for coal in the context of OMB good governance guidance. open.substack.com/pub/thesarap...
open.substack.com
A Lump of Coal in America's Stocking
Owning the liberals with a side of grift
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 21/07/2026
I like that you and xkcd both referenced Excalibur at the same time: m.xkcd.com
m.xkcd.com
xkcd: Arthurian Connector
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 17/07/2026
substack.com/@thesaraphre...
substack.com
Marcus C Sarofim (@thesaraphreport)
A useful explainer for those of us watching our skies fill with smoke. TL;DR - fire weather is increasing due to climate change. In California, historical fire suppression has also increased wildfire ...
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 16/07/2026
I'm in the "comment on everything!" phase of my career - see my post for counts of comments on the last four proposed regulations, and five more regs waiting for new comments: open.substack.com/pub/thesarap...
open.substack.com
Comment like the planet depends on it
The public is stepping up, but we have more to do
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Marcus C Sarofim @marcusmarcusrc.bsky.social · 14/07/2026
I thought your immigration book was masterful. I read smbc every day. And I’m buying a copy of Sawyer Lee for a friend’s kid who is a definite homebody. Thank you for all your creativity!
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