GitHub - iiasa/emissions_harmonization_historical: Scripts that combine historical emissions data records from several datasets like CEDS and GFED to create complete historical emissions for `IAMconso... Scripts that combine historical emissions data records from several datasets like CEDS and GFED to create complete historical emissions for `IAMconsortium/concordia` and `iiasa/climate-assessment`....

Finally - a huge thankyou to Zeb, Marit, Jarmo and Marco - who worked massively hard to make the backend to this process work. This code is all public on github. github.com/iiasa/emissi...

It's taken some time. There are good reasons for this - we took the community consultation seriously and made real changes to the design; ScenarioMIP bridges many communities across ESMs, IAMs and observations - and finding consensus, common language and technical solutions takes time.

Extensions: we're working with PNNL/LUH on translating the global land use pathways transitions to gridded land use transitions in a smooth way which approximately represents the AFOLU target trajectory. These should be done soon - with a dedicated paper on methodology.

VL & H are up on Input4MIPs already. Global/regional emissions are finalised already and gridded data ESM input data will be published in the coming weeks. input4mips-cvs.readthedocs.io/en/latest/da...

Stratospheric aerosol forcing for CMIP7 (part 1): Optical properties for pre-industrial, historical, and scenario simulations (version 2.2.1) Abstract. Stratospheric aerosols, most of which originate from explosive volcanic sulfur emissions into the stratosphere, are a key natural driver of climate variability. They are thus a forcing provi...

New in the final version: a dedicated section on natural forcings (solar; volcanic), a discussion scenario likelihood, and on equity and justice considerations in scenario design. egusphere.copernicus.org/preprints/20...

For CMIP7: most scenarios are designed to be run in emissions-driven mode, meaning carbon cycle feedbacks are part of the experiment rather than prescribed away - as we laid out here. This motivates effort to reproduce historical CO2 concentrations. egusphere.copernicus.org/preprints/20...

We also provide a more extensive assessment of the assumed removals in the extensions - putting cumulative removal assumptions in the context of limits to geological storage (and - spoiler alert: HL/LN extensions are challenged by these assessments) www.nature.com/articles/s41...

We revised scenario extensions to 2500 after review: smoother transitions at 2100, continuous derivatives across all forcing species, and land-use fluxes ramped to zero by 2150 rather than CMIP6 step-changing. The most extreme overshoot extension (H-ext-OS) was dropped in favour of HL-ext.

The final design includes 7 scenarios: Very Low (VL), Low-to-Negative (LN), Low (L), Medium-to-Low (ML), Medium (M), High (H), and a new addition — High-to-Low (HL), a late-mitigation trajectory that follows high emissions through mid-century before declining to net zero by 2100.

The Scenario Model Intercomparison Project for CMIP7 (ScenarioMIP-CMIP7) Abstract. Scenarios serve as a critical tool in climate change analysis, enabling the exploration of future evolution of the climate system, climate impacts, and the human system (including mitigation...

So... now we can breathe again. Let's talk about ScenarioMIP.

The final version is now up on GMD - and there's some changes since the first draft. /THREAD/

gmd.copernicus.org/articles/19/...

Trump statement threatening Iran to open Strait of Hormuz

This is a horrifying threat of genocidal war crimes. The lives of civilians and service members alike are at stake here.

Congress must stop this war and remove Trump from the White House.

Final version now online: gmd.copernicus.org/articles/19/...

But this is not fantasy. We face, in a real sense, the possibility that the age of enlightenment may be finite. There is no greater modern representative of those values than NCAR and those who work and have worked there.

A world without it would be dark indeed.

And this impossible place, a portal to a more noble reality, persisted, increasingly at odds with a world which sought to attack the very concept of value in shared human understanding.

Until finally, the fragile powers vowed to tear it down, lest their doctrines be challenged by science.

And from this earthly monument came a different type of science, disconnected from the frantic egos of professors or the priorities of great powers, based rather on the sharing of knowledge across borders, without condition, so that all could better understand the workings of the planet.

Inside, there are sandstone halls of quiet reflection, with great windows framing the mountains - where the early giants of climate science built working models of our world and everything within it, powered by the quiet blinking lights of machines below.

The enlightenment realised. Simultaneously futuristic and ancient, the Mesa lab is a building from an alternative timeline, one where we built monuments to science rather than gods or money or power. It betrays scale - with no relatable features on the outside, it merges with the mountain.

One reason LLMs are a limited way of understanding the world is because the world is only partly defined in terms of texts.

- As an autistic person I am constantly confronted by how text and speech are incredibly unreliable guides to navigate the world.

4-year fully funded PhD position in 'Climate-related health impacts on children' @hydr-vub.bsky.social. Apply now:

jobs.vub.be/job/Elsene-P...

Sam Altman defends AI’s energy toll by saying it also takes a lot to ‘train a human’ OpenAI CEO also downplayed concerns about how much water datacenters require at AI summit in India

Here's we are, inconsiderately consuming food to support our inefficient biological neural networks

“it also takes a lot of energy to train a human ... It takes about 20 years of life – and all the food you consume during that time –before you become smart.”

www.theguardian.com/technology/2...

Kid this evening:

"Why do people talk about "the 90s" so much, that's like, a date in the future"

The science is, apparently, fine. We just decided it's beyond our remit to "protect" the "environment"

The federal government is setting itself up to be on the wrong end of the biggest lawsuit in history.

Next time someone asks you about energy and land use, maybe remind them that the ~35 million acres that currently grow corn for ethanol in the US could produce ~15 PWh per year of electricity from solar photovoltaics. That's ~3.5 times more than *total annual generation from all US power plants*.

My 2 cents: I would use the term ESM when active BGC components are running and fluxes can be diagnosed, whether or not they were running an em-driven protocol, I think. I feel like the term should describe what's running in the model, not how it's constrained.

Why methane surged in the atmosphere during the early 2020s The atmospheric methane (CH4) growth rate surged after 2019, peaking at 16.2 parts per billion per year (ppb year−1) in 2020 before declining to 8.6 ppb year−1 in 2023. Using multiple atmospheric inve...

The Methane spike in the early 2020’s has been explained in two new studies. A combination of weakened atmospheric removal and increased emissions from warming wetlands, rivers, lakes, and agricultural land are to blame.
www.science.org/doi/10.1126/... 
www.science.org/doi/10.1126/...
#methane

A Secret Panel to Question Climate Science Was Unlawful, Judge Rules

The Trump #climate report attempting to overturn the ruling that greenhouse gases are pollutants was grossly scientifically inaccurate. Turns out it was also illegal.
#climatechange

www.nytimes.com/2026/01/30/c...

Top engineers at Anthropic, OpenAI say AI now writes 100% of their code—with big implications for the future of software development jobs | Fortune AI coding tools are getting more sophisticated. But if coders stop coding, what happens to software development jobs?

"For Claude Code, about 90% of its code is written by Claude Code itself."

No judgement. But where the hell are we headed?

fortune.com/2026/01/29/1...

11:45 AM – 1:00 PM | A Look at Key Findings in the DoE Climate Report This panel will examine the Department of Energy’s 2025 , A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate, focusing on three core areas: whether trends in heat, precipitation, and hurricanes are worsening; how accurately climate models are tracking observed surface and atmospheric temperatures over the past century; and the extent to which climate change is likely to affect long-term economic growth. John Christy — University of Alabama Andrew Dessler — Texas A&M Steve Koonin — Hoover Institution Ross McKitrick — University of Guelph Moderator: Michael Toth — Civitas Institute

wow, this event looks interesting!
www.civitasinstitute.org/events/power...

In just four years, California went from 3% to 22% battery power storage, allowing excess daytime solar power generation to be stored for use at night. Increasing wind power generation, which peaks at night can also displace the need for some battery power, further dropping system cost and adding to grid stability.

A past criticism of Variable Renewables Energy (VRE) from wind & solar was that their power was intermittent & thus unreliable. But the drop in battery storage cost has ushered in the age of firmed renewable energy (FRE). Renewables with storage are displacing import and fossil fuels. 🧪🔌💡☀️💨💧🔋