Charlie Koven
LightNews LightNews
banner
ckoven.bsky.social
Charlie Koven
@ckoven.bsky.social
2.3K followers 560 following 85 posts
Climate and carbon cycle scientist. I help make computer models of the biosphere and experiment on them so that we don't have to on the real one.

https://scholar.google.com/citations?user=fB5Lnz4AAAAJ
Posts Replies Media Videos
ckoven.bsky.social
Really excited to see the flat10MIP paper out! Since the preprint, we've added this new figure, showing the ESM ensemble of warming—normalized by the warming at year 100, to remove the uncertainty due to differing TCRE across models—versus cumulative CO2 emissions in the esm-flat10-cdr experiment.
A graph whose horizontal axis reads "Cumulative CO2 Emissions (Pg C)" and vertical axis reads "Normalized Warming (∆T/TCRE)". There is a narrow red ensemble plume, representing temperature during the positive CO2 emissions phase, which follows a straight dashed line, whose slope is 1/1000 (i.e the TCRE line, since warming is normalized to have a value of 1 at 1000 Pg C), and a blue ensemble plume, representing the temperature during the negative CO2 emission phase, which follows roughly the same slope but has a much wider ensemble spread. The acronym TCRE refers to the "transient climate response to cumulative CO2 emissions", which is the value of the proportionality between global warming and cumulative CO2 emissions.
September 5, 2025 at 5:29 PM
ckoven.bsky.social
Saw Kraftwerk play at the Berkeley Greek Theater last night, which happens to be right in front of the @nersc.bsky.social computers, on which I happen to have some global carbon cycle simulations running at the moment. Fun intersection of different computer worlds!
A large open-air ampitheater with a backdrop of classical columns made of concrete, bathed in green light. The ampitheater is full of a large audience. On stage are four people in front of keyboards, all wearing glowing green suits. Behind the four people is a large screen with the numbers 1 through 8. Four people on stage, with a classical concrete backdrop. The four people are playing keyboards and wearing costumes that glow white. Behind them is a large screen that says “COMPUTERWORLD” in front of a background of ones and zeros.
April 19, 2025 at 3:30 PM
ckoven.bsky.social
@queenofpeat.bsky.social moderating a panel of early career scientists who are all leading new synthesis products via the Permafrost Carbon Network. Really exciting to see all of this amazing work happening!
December 8, 2024 at 4:31 PM
ckoven.bsky.social
A thing I love about my ebike commute to work at @berkeleylab.bsky.social is all the random stuff one notices but would miss in a car. This morning’s installment: clouds of insects hovering at the tips of every coast live oak tree crown on one of the hillsides.
December 4, 2024 at 5:26 PM
ckoven.bsky.social
First chanterelle of the season in Berkeley, just in time for Thanksgiving
A Yellow mushroom peeking out from under a tangle of branches, leaves, mosses, and fern fronds A California golden chanterelle held in a hand
November 28, 2024 at 1:19 AM
ckoven.bsky.social
Is there a word for the fear and hatred of wetlands, and if not, shouldn’t there be one, so that we can label it when we see it? Paludiphobia?
A view of shallow water with eelgrasses just below the water surface. In the distance are sand dunes and fog. Morro Bay, California.
November 27, 2024 at 4:05 AM
ckoven.bsky.social
The answer is that the models do show path dependencies, and they are all correlated, but the correlation weakens on longer timescales. So, for example, globally, temperature would stop rising anywhere from decades before to decades after net zero, and the timing is closely correlated with ZEC.
November 15, 2024 at 5:18 PM
ckoven.bsky.social
We can try to estimate some of these potential path dependencies using metrics derived from the flat10MIP experiments. So, in addition to ZEC, we quantified a set of other path dependencies using the experiment where emissions gradually go through net zero, all the way back to cumulative net zero.
November 15, 2024 at 5:18 PM
ckoven.bsky.social
Comet over the Golden Gate.
A sunset view with urban lights in the foreground, a bridge just below the horizon, and a sky fading from orange to blue, with a comet and its tail visible.
October 14, 2024 at 3:10 AM
ckoven.bsky.social
Berkeley aurora. I find it very strange how distinctly the phone camera picks up something that is barely visible to the eye.
nighttime landscape, with city lights and low hills on the horizon, some trees in the foreground, a reservoir behind the trees, and pinkish streaks in the sky another nighttime landscape, with city lights and low hills on the horizon, some trees in the foreground, a reservoir behind the trees, and pinkish streaks in the sky another nighttime landscape, with city lights and low hills on the horizon, some trees in the foreground, a reservoir behind the trees, and pinkish streaks in the sky. this time the pinkish streaks are spread further apart.
October 11, 2024 at 5:35 AM
ckoven.bsky.social
Yes! But I guess they needed to offset it with some new bizarrely indirect phrase somewhere in the article?
September 1, 2024 at 1:59 AM
ckoven.bsky.social
Great new paper by Gordon Bonan and others on the deep historical legacies that limit how we think about the biosphere within the climate system, and the need to more fully represent diverse ways of understanding nature in the face of climate change.

agupubs.onlinelibrary.wiley.com/doi/10.1029/...
August 23, 2024 at 3:31 PM
ckoven.bsky.social
I mean, I very much appreciate what you are trying to do here BART, but
A sign that reads, “Without BART, we'd have to plant a new San Francisco sized forest every 2 years to offset the extra CO2”, but the 2 in CO2 is up high instead of down low.
May 23, 2024 at 12:25 AM
ckoven.bsky.social
Aurora in Berkeley, California!
May 11, 2024 at 8:04 AM
ckoven.bsky.social
Happy solstice everyone!
Chanterelle mushrooms hiding under a thick layer of forest litter. About twenty chanterelle mushrooms on a wooden table.
December 22, 2023 at 6:33 PM
ckoven.bsky.social
For those at AGU, I'll be talking today about carbon and climate responses during transitions to net-zero and net-negative emissions, and asking whether this slide from Al Gore's recent TED talk via @michaelemann.bsky.social is consistent with our best understanding. agu.confex.com/agu/fm23/mee...
A slide from Al Gore's recent TED talk that reads "Once the world reaches net zero CO2 emissions global temperatures will stop increasing in as soon as three to five years -- Michael Mann, Distinguished Professor of Atmospheric Sciences and Director, Earth System Science Center at Penn State".
December 14, 2023 at 3:30 PM
ckoven.bsky.social
Mushroom season off to a good start in the Berkeley/Oakland hills.
Coccora mushroom (Amanita calyptroderma) growing through its veil. bolete mushroom with a very thick stalk a large coccora mushroom (Amanita calyptroderma) in my hand bolete mushroom on a table with a hand for scale, the mushroom and hand are about the same size.
November 26, 2023 at 11:50 PM
ckoven.bsky.social
brief hole in the fog
partial solar eclipse veiled by fog
October 14, 2023 at 4:22 PM
ckoven.bsky.social
Smoke season grey skies for bluesky: the view from Berkeley Lab today.
September 20, 2023 at 4:42 PM
ckoven.bsky.social
smoke season has officially arrived in the bay area today.
September 20, 2023 at 2:25 AM