Chris Smith
@cjsmith.be
Climate scientist at Vrije Universiteit Brussel & IIASA. IPCC AR7 CLA. Responsive climate projections. The guy behind the fair model and radiative forcing barchart. Occasional runner and guitarist.
github.com/chrisroadmap | cjsmith.eu
github.com/chrisroadmap | cjsmith.eu
A sneak peak of hopefully what is to come in CMIP7. We ran two CMIP6 climate models in CO2 emissions driven mode to 2300 - and the responses in the long term are very different.
Preprint: egusphere.copernicus.org/preprints/20...
Preprint: egusphere.copernicus.org/preprints/20...
November 7, 2025 at 11:48 AM
A sneak peak of hopefully what is to come in CMIP7. We ran two CMIP6 climate models in CO2 emissions driven mode to 2300 - and the responses in the long term are very different.
Preprint: egusphere.copernicus.org/preprints/20...
Preprint: egusphere.copernicus.org/preprints/20...
The FRIDA overview paper: gmd.copernicus.org/articles/18/...
A coupled human-Earth IAM, with integrated climate impacts.
A coupled human-Earth IAM, with integrated climate impacts.
An overview of FRIDA v2.1: a feedback-based, fully coupled, global integrated assessment model of climate and humans
Abstract. The current crop of models assessed by the Intergovernmental Panel on Climate Change (IPCC) to produce their assessment reports lack endogenous process-based representations of climate-drive...
gmd.copernicus.org
October 30, 2025 at 8:26 AM
The FRIDA overview paper: gmd.copernicus.org/articles/18/...
A coupled human-Earth IAM, with integrated climate impacts.
A coupled human-Earth IAM, with integrated climate impacts.
Has anybody ever looked at the IPCC AR5 scenario database and run them in a simple climate model? I'm curious to know how many would get close to 1.5°C - probably not many if the earliest net zero CO2 date is ~2060. Interesting to see how ambition has evolved over time at the low end
October 28, 2025 at 3:23 PM
Has anybody ever looked at the IPCC AR5 scenario database and run them in a simple climate model? I'm curious to know how many would get close to 1.5°C - probably not many if the earliest net zero CO2 date is ~2060. Interesting to see how ambition has evolved over time at the low end
Carbon Brief article on our committed sea-level rise paper: www.carbonbrief.org/rapid-emissi...
Rapid emissions cuts would avoid 64cm of ‘locked in’ sea level rise by 2300 - Carbon Brief
Cutting emissions in line with the 1.5C warming limit, rather than following current climate policies, could curb long-term sea level rise by 64cm.
www.carbonbrief.org
October 27, 2025 at 9:51 AM
Carbon Brief article on our committed sea-level rise paper: www.carbonbrief.org/rapid-emissi...
Reposted by Chris Smith
Really important paper led by my @iiasa.ac.at colleague Alex Nauels www.nature.com/articles/s41...
“The difference between decisive climate action today and continued high emissions is not just measured in degrees of warming but also in meters of sea-level rise” 👏👏👏
“The difference between decisive climate action today and continued high emissions is not just measured in degrees of warming but also in meters of sea-level rise” 👏👏👏
Multi-century global and regional sea-level rise commitments from cumulative greenhouse gas emissions in the coming decades - Nature Climate Change
It is important to understand how much long-term sea-level rise is already committed due to historical and near-term emissions. Here the authors use a modelling framework to show how decisions on glob...
www.nature.com
October 24, 2025 at 10:40 AM
Really important paper led by my @iiasa.ac.at colleague Alex Nauels www.nature.com/articles/s41...
“The difference between decisive climate action today and continued high emissions is not just measured in degrees of warming but also in meters of sea-level rise” 👏👏👏
“The difference between decisive climate action today and continued high emissions is not just measured in degrees of warming but also in meters of sea-level rise” 👏👏👏
How to contribute to fair:
✅submit a pull request
✅wait 6 months
✅track me down in person and remind me to review it
v2.2.3 now available at the usual places.
pypi.org/project/fair
anaconda.org/conda-forge/fair
✅submit a pull request
✅wait 6 months
✅track me down in person and remind me to review it
v2.2.3 now available at the usual places.
pypi.org/project/fair
anaconda.org/conda-forge/fair
Fair | Anaconda.org
anaconda.org
October 12, 2025 at 5:40 PM
How to contribute to fair:
✅submit a pull request
✅wait 6 months
✅track me down in person and remind me to review it
v2.2.3 now available at the usual places.
pypi.org/project/fair
anaconda.org/conda-forge/fair
✅submit a pull request
✅wait 6 months
✅track me down in person and remind me to review it
v2.2.3 now available at the usual places.
pypi.org/project/fair
anaconda.org/conda-forge/fair
RFMIP2 preprint now out! egusphere.copernicus.org/preprints/20...
The Radiative Forcing Model Intercomparison Project (RFMIP2.0) for CMIP7
Abstract. An external perturbation to the climate system from anthropogenic or natural activity first impacts the climate by inducing a perturbation to Earth’s energy budget, known as a radiative forc...
egusphere.copernicus.org
September 17, 2025 at 1:08 PM
RFMIP2 preprint now out! egusphere.copernicus.org/preprints/20...
If you want to get your simple climate model picked up by IPCC AR7, see below 👇
We have 11 on our radar from the previous round of RCMIP (egusphere.copernicus.org/preprints/20...), plus a few others we found since.
Anybody we don't know about please ping me or Alex
We have 11 on our radar from the previous round of RCMIP (egusphere.copernicus.org/preprints/20...), plus a few others we found since.
Anybody we don't know about please ping me or Alex
September 10, 2025 at 10:22 AM
If you want to get your simple climate model picked up by IPCC AR7, see below 👇
We have 11 on our radar from the previous round of RCMIP (egusphere.copernicus.org/preprints/20...), plus a few others we found since.
Anybody we don't know about please ping me or Alex
We have 11 on our radar from the previous round of RCMIP (egusphere.copernicus.org/preprints/20...), plus a few others we found since.
Anybody we don't know about please ping me or Alex
flat10-MIP has landed! gmd.copernicus.org/articles/18/...
flat10MIP: an emissions-driven experiment to diagnose the climate response to positive, zero and negative CO2 emissions
Abstract. The proportionality between global mean temperature and cumulative emissions of CO2 predicted in Earth system models (ESMs) is the foundation of carbon budgeting frameworks. Deviations from ...
gmd.copernicus.org
September 5, 2025 at 8:30 AM
flat10-MIP has landed! gmd.copernicus.org/articles/18/...
Now that it's public, I'm very honoured to be selected as Coordinating Lead Author of Chapter 5, Working Group I for the IPCC Seventh Assessment Report 📚🌍
Our chapter is one hell of a team!
Full author list for all three working groups: apps.ipcc.ch/report/autho...
Our chapter is one hell of a team!
Full author list for all three working groups: apps.ipcc.ch/report/autho...
IPCC Authors
apps.ipcc.ch
August 28, 2025 at 3:29 PM
Now that it's public, I'm very honoured to be selected as Coordinating Lead Author of Chapter 5, Working Group I for the IPCC Seventh Assessment Report 📚🌍
Our chapter is one hell of a team!
Full author list for all three working groups: apps.ipcc.ch/report/autho...
Our chapter is one hell of a team!
Full author list for all three working groups: apps.ipcc.ch/report/autho...
A deep dive into the world of simple climate models: preprint out from @arp-climate.bsky.social.
we know this isn't exhaustive - we focus on the models that participated in RCMIP phases 1 and 2. There will be a phase 3, coming soon.
we know this isn't exhaustive - we focus on the models that participated in RCMIP phases 1 and 2. There will be a phase 3, coming soon.
August 12, 2025 at 11:16 AM
A deep dive into the world of simple climate models: preprint out from @arp-climate.bsky.social.
we know this isn't exhaustive - we focus on the models that participated in RCMIP phases 1 and 2. There will be a phase 3, coming soon.
we know this isn't exhaustive - we focus on the models that participated in RCMIP phases 1 and 2. There will be a phase 3, coming soon.
We (@tim-andrews.bsky.social, Ryan Kramer and I) are leading a session around understanding radiative forcing in models at the CMIP Community Workshop in Kyoto, Japan, next March. Abstract submissions open until 13 August:
wcrp-cmip.org/event/cmip20...
Session ID #4
wcrp-cmip.org/event/cmip20...
Session ID #4
CMIP Community Workshop 2026 - Coupled Model Intercomparison Project
The CMIP Community Workshop 2026 will bring together a growing, and increasingly diverse, community of Earth system scientists, partners, and stakeholders. It
wcrp-cmip.org
July 4, 2025 at 6:58 AM
We (@tim-andrews.bsky.social, Ryan Kramer and I) are leading a session around understanding radiative forcing in models at the CMIP Community Workshop in Kyoto, Japan, next March. Abstract submissions open until 13 August:
wcrp-cmip.org/event/cmip20...
Session ID #4
wcrp-cmip.org/event/cmip20...
Session ID #4
Including a climate module and climate damages within a process-based integrated assessment model: meet FRIDA.
egusphere.copernicus.org/preprints/20...
egusphere.copernicus.org/preprints/20...
Introducing FRIDA v2.1: A feedback-based, fully coupled, global integrated assessment model of climate and humans
Abstract. The current crop of models assessed by the Intergovernmental Panel on Climate Change (IPCC) to produce their assessment reports lack endogenous process-based representations of climate-drive...
egusphere.copernicus.org
June 26, 2025 at 9:44 AM
Including a climate module and climate damages within a process-based integrated assessment model: meet FRIDA.
egusphere.copernicus.org/preprints/20...
egusphere.copernicus.org/preprints/20...
Hello world, who else is in Vienna this week?
June 24, 2025 at 1:30 PM
Hello world, who else is in Vienna this week?
Reposted by Chris Smith
Please get in touch with Team @carbonbrief.org if you're in Bonn this week – @mollylempriere.carbonbrief.org + @joshgabbatiss.bsky.social have just arrived
It's that time of year again!
I'll be in Bonn covering the #SB62 UN climate talks until the end of the week with @mollylempriere.carbonbrief.org
Keen to hear the hot takes on climate finance, loss and damage and anything else you think is interesting
I'll be in Bonn covering the #SB62 UN climate talks until the end of the week with @mollylempriere.carbonbrief.org
Keen to hear the hot takes on climate finance, loss and damage and anything else you think is interesting
June 23, 2025 at 3:46 PM
Please get in touch with Team @carbonbrief.org if you're in Bonn this week – @mollylempriere.carbonbrief.org + @joshgabbatiss.bsky.social have just arrived
In this Carbon Brief post we talk about the implications of not including future volcanic eruptions in climate scenarios, as described in our recent paper: www.nature.com/articles/s43...
June 23, 2025 at 3:51 PM
In this Carbon Brief post we talk about the implications of not including future volcanic eruptions in climate scenarios, as described in our recent paper: www.nature.com/articles/s43...
I'll be giving a short talk on 1.5°C at a mini-symposium at VUB on Friday 6 June as part of an event celebrating the award of an honorary doctorate to @joerirogelj.bsky.social, see below for details and registration!
Van harte welkom op het symposium "In gesprek met topklimaatwetenschapper Joeri Rogelj" nu vrijdag 9-12h @vubrussel.bsky.social, met keynote van @joerirogelj.bsky.social en korte lezingen van @cjsmith.be, @cohelongo.bsky.social, @harryzeko.bsky.social & mezelf. receptie. www.vub.be/nl/evenement...
In gesprek met topklimaatwetenschapper Joeri Rogelj | 6 juni 2025
Mis de keynote van Joeri Rogelj niet, die is aangevuld met sprekers uit domeinen zoals klimaatwetenschap, beleid, scenario's en rechtszaken.
www.vub.be
June 3, 2025 at 10:11 AM
I'll be giving a short talk on 1.5°C at a mini-symposium at VUB on Friday 6 June as part of an event celebrating the award of an honorary doctorate to @joerirogelj.bsky.social, see below for details and registration!
Reposted by Chris Smith
Some sessions that ought to be fun & interesting:
🔷 ID4 RFMIP: Exploring radiative Forcing in models and observations to understand climate change
🔷 ID5 CERESMIP: Confronting models with observed changes in the Earth’s energy imbalance
🔷 ID15 CFMIP: Clouds, circulation and climate sensitivity
🔷 ID4 RFMIP: Exploring radiative Forcing in models and observations to understand climate change
🔷 ID5 CERESMIP: Confronting models with observed changes in the Earth’s energy imbalance
🔷 ID15 CFMIP: Clouds, circulation and climate sensitivity
The CMIP Community Workshop 2026 will be held in Kyoto, Japan from 9-13th March 2026. The call for abstracts for CMIP26 is now open! Find out more at wcrp-cmip.org/cmip26-call-...
May 29, 2025 at 12:53 PM
Some sessions that ought to be fun & interesting:
🔷 ID4 RFMIP: Exploring radiative Forcing in models and observations to understand climate change
🔷 ID5 CERESMIP: Confronting models with observed changes in the Earth’s energy imbalance
🔷 ID15 CFMIP: Clouds, circulation and climate sensitivity
🔷 ID4 RFMIP: Exploring radiative Forcing in models and observations to understand climate change
🔷 ID5 CERESMIP: Confronting models with observed changes in the Earth’s energy imbalance
🔷 ID15 CFMIP: Clouds, circulation and climate sensitivity
Reposted by Chris Smith
Very cool that @carbonbrief.org @ayeshatandon.carbonbrief.org have covered our study, take a read here!
NEW – ‘Significant’ risk of Amazon forest dieback if global warming overshoots 1.5C | @ayeshatandon.carbonbrief.org w/ comment from @gergmunday.bsky.social Nico Wunderling @davidamckay.bsky.social David Lapola @chrisd-jones.bsky.social
‘Significant’ risk of Amazon forest dieback if global warming overshoots 1.5C - Carbon Brief
Even passing 1.5C of global warming temporarily would trigger a “significant” risk of Amazon forest “dieback”, says a new study.
buff.ly
May 16, 2025 at 9:58 AM
Very cool that @carbonbrief.org @ayeshatandon.carbonbrief.org have covered our study, take a read here!
Reposted by Chris Smith
New paper on the risks of forest ecosystem impacts under emissions pathways designed to meet the Paris Agreement temperature goals is out today in Nature Climate Change! 🌳
Read it here: www.nature.com/articles/s41558-025-02327-9
Read it here: www.nature.com/articles/s41558-025-02327-9
www.nature.com
May 12, 2025 at 9:14 AM
New paper on the risks of forest ecosystem impacts under emissions pathways designed to meet the Paris Agreement temperature goals is out today in Nature Climate Change! 🌳
Read it here: www.nature.com/articles/s41558-025-02327-9
Read it here: www.nature.com/articles/s41558-025-02327-9
To all of my friends in Oslo, I am presenting at the Joint Oslo Seminar tomorrow at UiO! It will be the full-fat version of my EGU talk:
Updated IPCC emissions scenarios no longer limit warming to 1.5°C
Details 👇
www.mn.uio.no/geo/english/...
Updated IPCC emissions scenarios no longer limit warming to 1.5°C
Details 👇
www.mn.uio.no/geo/english/...
May 7, 2025 at 5:53 PM
To all of my friends in Oslo, I am presenting at the Joint Oslo Seminar tomorrow at UiO! It will be the full-fat version of my EGU talk:
Updated IPCC emissions scenarios no longer limit warming to 1.5°C
Details 👇
www.mn.uio.no/geo/english/...
Updated IPCC emissions scenarios no longer limit warming to 1.5°C
Details 👇
www.mn.uio.no/geo/english/...
Reposted by Chris Smith
Very excited to announce that the call for abstracts for our @iiasa.ac.at overshoot conference is out.
Join us to explore the eightfold path to manage climate risks of an overshoot world:
overshootconference.org
Abstract deadline: June 27.
Join us to explore the eightfold path to manage climate risks of an overshoot world:
overshootconference.org
Abstract deadline: June 27.
Overshoot |
overshootconference.org
May 5, 2025 at 7:10 PM
Very excited to announce that the call for abstracts for our @iiasa.ac.at overshoot conference is out.
Join us to explore the eightfold path to manage climate risks of an overshoot world:
overshootconference.org
Abstract deadline: June 27.
Join us to explore the eightfold path to manage climate risks of an overshoot world:
overshootconference.org
Abstract deadline: June 27.
The preprint for Indicators of Global Climate Change 2024 is now up for public discussion in ESSD.
essd.copernicus.org/preprints/es...
essd.copernicus.org/preprints/es...
Indicators of Global Climate Change 2024: annual update of key indicators of the state of the climate system and human influence
Abstract. In a rapidly changing climate, evidence-based decision-making benefits from up-to-date and timely information. Here we compile monitoring datasets (published here https://doi.org/10.5281/zen...
essd.copernicus.org
May 5, 2025 at 1:04 PM
The preprint for Indicators of Global Climate Change 2024 is now up for public discussion in ESSD.
essd.copernicus.org/preprints/es...
essd.copernicus.org/preprints/es...
Here's @arp-climate.bsky.social presenting on the upcoming process-based carbon cycle in FaIR at #EGU25!
April 30, 2025 at 1:50 PM
Here's @arp-climate.bsky.social presenting on the upcoming process-based carbon cycle in FaIR at #EGU25!
Is 1.5°C still within reach? Find out tomorrow (Tuesday) at #EGU25
09:15, room 0.31/32, session CL3.2.1
meetingorganizer.copernicus.org/EGU25/EGU25-...
09:15, room 0.31/32, session CL3.2.1
meetingorganizer.copernicus.org/EGU25/EGU25-...
Abstract EGU25-11441
meetingorganizer.copernicus.org
April 28, 2025 at 8:43 PM
Is 1.5°C still within reach? Find out tomorrow (Tuesday) at #EGU25
09:15, room 0.31/32, session CL3.2.1
meetingorganizer.copernicus.org/EGU25/EGU25-...
09:15, room 0.31/32, session CL3.2.1
meetingorganizer.copernicus.org/EGU25/EGU25-...