Pierre Friedlingstein

We actually have evidence of the opposite, climate change reduces the efficiency of the carbon cycle to remove anthropogenic CO₂ …

And this now, coming from the DOE 😰

www.energy.gov/sites/defaul...

Have you seen the new DOE report? 😳

www.energy.gov/sites/defaul...

Figure 4(a) Effective radiative forcing (ERF) statistics across AR6 scenario database subsets as categorised by AR6WGIII using MAGICC for CO2, CH4, F-gases, and aerosols at different points in time for three climate emulators. Kikstra, J. S., Nicholls, Z. R. J., Smith, C. J., Lewis, J., Lamboll, R. D., Byers, E., Sandstad, M., Meinshausen, M., Gidden, M. J., Rogelj, J., Kriegler, E., Peters, G. P., Fuglestvedt, J. S., Skeie, R. B., Samset, B. H., Wienpahl, L., van Vuuren, D. P., van der Wijst, K.-I., Al Khourdajie, A., Forster, P. M., Reisinger, A., Schaeffer, R., and Riahi, K.: The IPCC Sixth Assessment Report WGIII climate assessment of mitigation pathways: from emissions to global temperatures, Geosci. Model Dev., 15, 9075–9109, https://doi.org/10.5194/gmd-15-9075-2022, 2022.

It is CO2 radiative forcing that poses the largest end-of-century climate threat, because CO2 accumulates in the atmosphere.

[C1-C4 are lower, and C5-C8 higher, IPCC temperature scenarios; ERF is effective radiative forcing.]

Nice paper.

gmd.copernicus.org/articles/15/...
@kikstra.bsky.social

Fearless! That’s borderline scary 😉

Nice photo indeed 😉

Air and greenhouse gas pollution from private jets, 2023 - International Council on Clean Transportation The report fills a gap in our understanding of aviation's environmental impact by providing the first detailed global mapping of air and climate pollution from private jets.

Excited to release today with Daniel Sitompul ICCT's first air and GHG inventory for private jets. A lot of eye opening statistics in this report. Let me walk you through a few. (🧵)
theicct.org/publication/...

Couldn’t agree more

PS I’m not debating the existence of an acceleration, CO₂ emissions almost doubled since 1990 🙁

Isn’t a trend over 15 years potentially too short to say ? (unless you have removed the natural variability ?).
A bit like the warming hiatus but opposite 😉

That’s not true. If we could stop emitting GHG now, warming would essentially stop.

Indeed. That’s my job (global carbon cycle modeling).
I’m cutting the branch I’m sitting on 😉

So yes, I would rather have more brains looking at solutions than brains looking at what will happen if we don’t have any solution …

I would argue we understand ecosystem impacts well enough to know that we have to cut GHG emissions as soon as possible 😉

“the wedding of the century”
🙄
Definitely in terms of CO₂ emissions ! 😡

First time I hear this. Would be good to see some evidence of this statement.
The Rio Earth summit was about 15 years before the scientific community realized that zero emissions was needed to stop global warming.
The narrative at that time was about stabilizing GHG concentrations.

Researchers call for urgent exploration of methods to cool Earth Ideas include injecting sulphates into the atmosphere to reflect sunlight but this could do more harm than good

In @theguardian.com
about geo engineering
“If these ideas are otherwise harmless, and work, they might yet save us.”.

No they won’t. The only “idea” that can save us is bringing greenhouse gases emissions to zero !

www.theguardian.com/environment/...

Ok bye flat earther.
Your opinion is irrelevant.

I would suggest you read the IPCC AR6 synthesis report. Especially section 3.4 and underlying WG chapters.

You lost me here. Are you suggesting there is no point limiting climate change ?

That’s the principle of “common but differentiated responsibilities”, central to the UNFCCC process.
But I suspect you already know that…

“Based on a detailed sectoral assessment of mitigation options, it is estimated that mitigation options costing USD100 tCO2-eq –1 or less could reduce global GHG emissions by at least half of the 2019 level by 2030”

It’s not *impossible* indeed. The IPCC WG3 assesses options for emission mitigation across all sectors (transport, energy, industry, land use, etc).

Climate science as any other human activity has a carbon footprint. We need to reduce it as much as possible indeed.

All choices are subjective 😉

Set the clock to 1.6C 😉

One can say that the threshold is political (could be 1.5C or 2C for example).
But the associated remaining carbon budget only relies on climate physics.

Résumé de la publication (aujourd’hui) sur les indicateurs de changement climatique.
Pas bcp de bonnes nouvelles. 1.5C se rapproche inexorablement.