Chris Smith | Lightnews

Chris Smith @cjsmith.be · 2d

Cool, thanks Abby! I was aware of this paper but don't think I cited it (my bad) - the running to 2300 is there and we can compare the carbon sinks, but the experiments were concentration-driven, and didn't include the lower scenarios, and they don't have NorESM, which is a super interesting model!

Chris Smith @cjsmith.be · 3d

Unfortunately not. These were from the CMIP6 ESGF - was really a shame that not many models extended beyond 2100.

Chris Smith @cjsmith.be · 3d

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...

temperature and CO2 projections from MPI-ESM1.2-LR and NorESM2-LM under three emissions scenarios to 2300

Chris Smith @cjsmith.be · 12d

The FRIDA overview paper: gmd.copernicus.org/articles/18/...

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

Chris Smith @cjsmith.be · 13d

I should have known this...

There are 1.5°C no and low overshoot scenarios in AR5, but they are cooler in 2020 than we have observed, suggesting that mitigation would have started in the 2010s.

It would be good to do this consistently harmonized in the same simple climate model

Chris Smith @cjsmith.be · 13d

yeh, precisely this! I mean, one of the successes of the Paris Agreement (or failure of pre-Paris climate policy?) is that nobody was really looking at 1.5°C scenarios before 2016. I'm just interested to see if anyone has done a like-for-like climate comparison. If not, I might :)

Chris Smith @cjsmith.be · 13d

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

GHG and CO2 emissions plumes from emissions scenarios submitted to the IPCC Fifth Assessment Report Working Group III.

Chris Smith @cjsmith.be · 14d

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

Carl Schleussner @carlschleussner.bsky.social · 17d

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” 👏👏👏

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

Chris Smith @cjsmith.be · 29d

windows will restart now

Chris Smith @cjsmith.be · 29d

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

Fair | Anaconda.org

anaconda.org

Chris Smith @cjsmith.be · Sep 18

I know!!! I was outvoted

Chris Smith @cjsmith.be · Sep 17

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

Chris Smith @cjsmith.be · Sep 10

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

Chris Smith @cjsmith.be · Sep 5

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

Chris Smith @cjsmith.be · Aug 31

send me a PM :)

Chris Smith @cjsmith.be · Aug 28

Belspo press release on the Belgian contribution to IPCC AR7:

FR: www.belspo.be/belspo/organ...
NL: www.belspo.be/belspo/organ...
EN: google translate ;)

Communiqué de presse | Belspo

Une fierté, mais aussi une responsabilité pour la Belgique

www.belspo.be

Chris Smith @cjsmith.be · Aug 28

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...

IPCC Authors

apps.ipcc.ch

Chris Smith @cjsmith.be · Aug 28

also very willing to help if you get stuck. Sorry the new interface is clunky - I went speed over intuition.

Chris Smith @cjsmith.be · Aug 12

turns out I'm an idiot and can't link to papers

egusphere.copernicus.org/preprints/20...

egusphere.copernicus.org

Chris Smith @cjsmith.be · Aug 12

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.

Thomas Rackow 🧊 @trackow.bsky.social · Dec 5

How much warming? That is where simple modelling can help. Turns out that the temperature response to the observed reduction in planetary albedo since December 2020 (estimated from a simple energy-balance #model, doi.org/10.1175/JCLI...) may explain the warming ‘gap’ of about 0.2K. (7/8)

Supplement to Goessling, Rackow, & Jung; Science, https://doi.org/10.1126/science.adq7280

Chris Smith @cjsmith.be · Feb 13

This water vapour input (green) more than offset the small cooling effect from a increase in stratospheric aerosol optical depth (blue), resulting in a net volcanic radiative forcing (purple) that is above the long-term quiescent baseline value for 2022-2024.

Chris Smith @cjsmith.be · Jul 4

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

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

Chris Smith @cjsmith.be · Jun 26

Including a climate module and climate damages within a process-based integrated assessment model: meet FRIDA.

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

Chris Smith @cjsmith.be · Jun 24

Hello world, who else is in Vienna this week?

Chris Smith @cjsmith.be · Jun 23

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...

Josh Gabbatiss @joshgabbatiss.bsky.social · Jun 23

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

Chris Smith @cjsmith.be · Jun 3

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!