David Harning

A 15,800 year record of productivity, carbon accumulation and environmental change at Eight Mile Lake and its catchment, central Alaska Despite their efficient burial of organic carbon (OC), the role of high-latitude lakes in storing and processing OC under changing climates is poorly understood. We investigate a 15,800 year sedime...

Check out our new paper about carbon, productivity and climate over 15,800 years in central Alaska. Out in @aaarjournal.bsky.social this paper pairs new sediment records from Eight Mile Lake with soil cores from the adjacent hillslope.

www.tandfonline.com/doi/full/10....

Shifting seas: understanding deep-time human impacts on marine ecosystems | Philosophical Transactions of the Royal Society B: Biological Sciences Humans have interacted with, and impacted, marine ecosystems for millennia. During this time, the oceans have experienced ecosystem degradation through harvesting, habitat change, pollution, the introduction of invasive species and climate change. Despite ...

🐚 Out today “Shifting Seas – Understanding Deep-Time Human Impacts on Marine Ecosystems.” 🌊

A theme issue asking how, when, and where humans have impacted oceans over millennia.

🔗 doi.org/10.1098/rstb.2024.0026

🧶 below on how it came to life!...

🚨The Trump Administration is proposing devastating cuts to key national agencies in Colorado that play a vital role in protecting our country, including through cutting-edge research on wildfires, droughts, and more.

Senator Bennet and I are fighting back against the attacks on NOAA, CIRES & CIRA 👇🏾

A Nutrient Effect on the TEX86 Paleotemperature Proxy Nutrient stress alters GDGT distributions in marine sediments, resulting in elevated TEX86 ${\text{TEX}}_{86}$ values beyond those related to thermal effects Paleoclimate case studies from the Ar...

Now published in @agu.org Geophysical Research Letters!

What happens to marine archaea when they’re hungry? And what does that mean for the TEX₈₆ paleothermometer?

Full paper here: doi.org/10.1029/2025...

Thanks to my coauthors and mentors for their support — and stay tuned, more is coming!

Postdoctoral Fellow: Self-Developed Project (280531) | University of Oslo Job title: Postdoctoral Fellow: Self-Developed Project (280531), Employer: University of Oslo, Deadline: Monday, June 23, 2025

Come postdoc in Oslo! 3 years. You design the project! Get in touch with me or others at our museum! Deadline 23 june www.jobbnorge.no/en/available... share and repost !

Sediment records provide a glimpse into Iceland’s past, and hope for its future Just a couple of kilometers inland from the coast of Northern Iceland, lie Torfdalsvatn, a small, deep freshwater lake. Winters here are frigid, snowy and dark,

A new paleoclimatology investigation, led by INSTAAR affiliate @davidharning.bsky.social (@cires.colorado.edu+NOAA NCEI), uncovers a story of ecosystem resilience at a lake in coastal Iceland. The analysis could aid future conservation and climate modeling efforts www.colorado.edu/instaar/2025...

Very excited to have this manuscript out!! During an #NSF Workshop, we brainstormed 100 future questions facing lake ice study today, and how we integrate #remotesensing #modeling #insitu work to get at those questions!
@agu.org #OpenAccess

Extreme Heat and Rain Turned These Arctic Lakes Brown - Eos Scientists are stunned by the changes in multiple Arctic lakes, all transforming in the same way.

Here’s what turned these Arctic lakes brown.

eos.org/articles/ext...

Read more in our May issue: bit.ly/Eos-May2025

Welcome to Save The U.S. National Science Foundation A Girl Looking at a Physics Model TAKE ACTION Save NSF is a coalition of concerned scientists and allies who are working to save funding for scientific grants through the U.S. National Science Foundation. Our mission is to support and advocate for the continuation of vital research and innovation in various scientific fields. NSF funding is critical to this work. Join us in our endeavor to ensure a sustainable future for scientific exploration and discovery.

I am so heartened to this seriously AWESOME #SaveNSF website go up today!!!!

Has a take action toolkit with:

1. Press outreach templates
2. Social media toolkit
3. Elected official outreach
4. Talking points

Check it out and share widely!!!! Likely more to come.

www.savensf.com

A person's finger points at a marine seismic profile showing the subsurface geology off Northwest Greenland. More specifically, they are pointing at a coring site where a 978 meter long sediment core was drilled during IODP Expedition 400 in 2023 aboard the RV JOIDES Resolution.

Anne Jennings in front of the JOIDES Resolution ship before they left for Greenland in August, 2023 (Credit: Philip Staudigel)

🚨 New ocean sediment drilling report
INSTAAR Fellow ANNE JENNINGS co-led IODP #Exp400, which collected cores off the NW Greenland glaciated margin in 2023... incl one 978m (3209ft) long! The team's (ongoing) work spans a lot of ice sheet & ocean history publications.iodp.org/proceedings/...

White House Plan Calls for NOAA Research Programs to Be Dismantled (Gift Article) A Trump administration budget proposal would essentially eliminate one of the world’s foremost Earth sciences research operations.

Critical yet often overlooked is that NOAA's Oceanic and Atmospheric Research maintains vital long-term monitoring programs like the CO₂ Keeling Curve that, while essential, often struggle for funding from agencies like NSF that prioritize hypothesis-driven research over sustained observation.

Isotopes in Palaeoenvironmental Research – A 20 year update This special issue of Quaternary Science Reviews comprises a series of review papers which discuss the application of stable isotopes to different typ…

This issue of Quaternary Science Reviews comprises reviews on stable isotopes in different types of records. This is an update of the 2004 issue on “Isotopes in Quaternary Paleoenvironmental Reconstruction (ISOPAL)”, volume 23, issue 7–8, pages 739–992. www.sciencedirect.com/science/arti...

Big thanks to all my collaborators to help make this one a reality, @yarrowaxford.bsky.social and others!

High-resolution Holocene record based on detailed tephrochronology from Torfdalsvatn, north Iceland, reveals natural and anthropogenic impacts on terrestrial and aquatic environments Abstract. Open questions remain around the Holocene variability of climate in Iceland, including the relative impacts of natural and anthropogenic factors on Late Holocene vegetation change and soil e...

New paper on Iceland! Over the last 20+ years, we've analyzed a bunch of high-resolution datasets from a small lake first studied in the early 90s. If you're interested in Holocene climate, tephra, algal pigments, and Norse settlement, this one might be for you: cp.copernicus.org/articles/21/...

To the world:
We are fighting back. Our movement has been silenced by the media here—but we are not backing down. This is what our streets looked like across multiple cities. Tomorrow, there will be more of us! Raise a glass to freedom.

—With love,
Your American allies.

Thawing the mysteries of ancient climate changes A new study from Chloe Brashear, Tyler Jones and others suggests abrupt warming events were preceded by periods of unusually stable temperatures during the last

🧊 New ice core study of the last ice age by Chloe Brashear, Tyler Jones et al. suggests abrupt warming events were preceded by periods of unusually stable temperatures. Shifting sea ice is a potential driver of the phenomenon.

Read our story: www.colorado.edu/instaar/2025...

📢 Job Alert!

We are looking for a Post-Doc / Research associate (f/m/d) in the field of #MarineGeochemistry at the International Core Repository at the Universität Bremen (A126-25).

⏰ Application- #Deadline is April 1st 2025
Find out more here ➡ www.marum.de/jobs
#jobs #wearehiring #Science

A brick wall with "NOAA" and the NOAA logo surrounded by snow-covered bushes.

An open letter to our federal colleagues and collaborators from CIRES Director Waleed Abdalati: cires.colorado.edu/news/cires-s...

"While the value of what you do may not be obvious to some, it benefits all. Your work is so important, and it is a true privilege being on the same team as you."

Hundreds of weather forecasters fired in latest wave of DOGE cuts Federal workers who were not let go said the afternoon layoffs included meteorologists who do crucial local forecasts in National Weather Service offices across the U.S.

@noaa.gov, one of the nation’s most prominent scientific agencies, began firing employees yesterday. The agency is expected to lose about 10% of its workforce. 🧵 👇https://apnews.com/article/national-weather-service-layoffs-trump-doge-a65360a1eb2500b7d47c9c966e383f4a

The Glacier Mass Balance Intercomparison Exercise is out! Herculean effort bringing together >200 estimates of glacier loss outside the ice sheets. Bottom line is 273 gigatonnes per year of ice loss since the year 2000! 😲

Open-access article: doi.org/10.1038/s415...

🥼❄️ @natureportfolio.nature.com

Host Species–Microbiome Interactions Contribute to Sphagnum Moss Growth Acclimation to Warming Sphagnum mosses are vital for storing carbon in northern peatlands but are sensitive to climate warming. They host microbes that help with nutrient uptake and carbon cycling, and recent studies sugge...

New work on how microbiome-moss interactions contribute to acclimation to warming.

onlinelibrary.wiley.com/doi/full/10....

Dreaming about fieldwork in Iceland now.

NOAA’s vast public weather data powers the local forecasts on your phone and TV – a private company alone couldn’t match it NOAA operates fleets of satellites, sensors on airplanes and ocean-going buoys, as well as radar, providing the data used by weather forecasters nationwide – and freely available to anyone.

"NOAA is taxpayer-funded, so it is a public good – its services provide safety and security for everyone, not just those who can pay for it." CIRES' @cwiedinm.bsky.social and Kari Bowen explain @noaa.gov's role in U.S. weather forecasts. @us.theconversation.com @colorado.edu

Over 2.5 billion years ago, trillions of tiny Cyanobacteria spent hundreds of millions of years creating an oxygen-rich atmosphere on Earth.

Take a deep breath. How are you using your oxygen today? Be present. Give freely. Care for others. Make your ancient microbial cousins proud. Exhale. Repeat.

NSF Implementation of Recent Executive Orders Information for the NSF community regarding executive orders.

Folks wanting updates from NSF, they just posted this:
new.nsf.gov/executive-or...

Stop work order for "conferences, trainings, workshops, considerations for staffing and participant selection, and any other grant activity that uses or promotes the use of DEIA principles and frameworks..."

Godt nytår! I'm hiring an isotope-loving postdoc with applications due January 15th 🇩🇰

Global mean sea level likely higher than present during the holocene Nature Communications - Sea level data and models of solid Earth effects and ocean thermal expansion are used to show that global mean sea level and Antarctic ice volume were likely higher and...

In a 🔥 new Nature Communications paper 🔥 led by me, Jacky Austermann, and @bobkopp.net, we show that global mean sea level was likely higher in the Holocene than at 1850. 🎁: rdcu.be/d5fHn 🧵

🔥New paper alert! 🔥 Jacky Austermann and I show that simultaneous Antarctic collapse + Laurentide persistence during the Last Interglacial (130,000 - 115,000 years ago) could explain the local sea level oscillation observed in the Bahamas, Seychelles, Australia, and elsewhere. tinyurl.com/yjj7w2mr 🧵

🧬 This newly published paper in Nature presents the oldest human genome sequenced to date: 45,000 years old !

It concludes that small, isolated groups of Homo sapiens lived in Europe at that time and interbred with Neanderthals, but left no descendants.

#Paleosky 🧪 🏺

With glaciers worldwide in retreat, you don't typically see moraine building. But at Yahtse Glacier, during my PhD project, we got a great look at the process responsible for so many critical reconstructions of glacier change and paleoclimate.

Enjoy! ⚒️🧪

The 3rd Ancient Environmental Genomics PhD course (2025) is now open for registration. This has been a true pleasure to teach (and hard work) both times. Come join us and have a week of in-depth hands-on work with ancient metagenomic data and the latest analysis tools. phdcourses.dk/Course/124659