Chris Jones

Abstract submission is now open for EGU25. We would love to get submissions for our session on TCRE and ZEC: meetingorganizer.copernicus.org/EGU25/sessio...
Deadline 15 Jan.

Work presented can contribute to the WCRP assessment – see www.wcrp-climate.org/slc-events-o...

Why are CO2 emissions still going up? What are the key factors behind the increase, & when will they peak and start heading down?

Wednesday 20 Nov 830-930, in person (Oslo) & streamed

Register @ciceroclimate.bsky.social: www.linkedin.com/feed/update/...

fair comment - and of course "climate" (i.e. local conditions, extremes etc) doesn't necessarily stabilise just because global T does.

I think the bigger issue is not just the definitions, but the concept of offsetting fossil emissions by ecosystem removals. Simply not sustainable in the long run

Aligning climate scenarios to emissions inventories shifts global benchmarks - Nature Aligning the IPCC-assessed mitigation pathways with the national greenhouse gas inventories shows that key global mitigation benchmarks become harder to achieve, requiring achieving earlier net-z...

There are papers already – Giacomo Grassi and co have been highlighting this for a while. See e.g.:
www.nature.com/articles/s41...
www.nature.com/articles/d41...

it’s not small (and ironically can come back to bite you later as the sink may saturate and reverse!)

Watch out next week for a new paper calling for more clarity in what we mean and how progress is reported.

Ultimately “natural” sinks and land-based managed sinks can only offset so much from fossil fuels. Any sustainable “net zero” must mean “geological net zero”

leave it in the ground!

So what does all this mean? Neither is wrong – they just differ. But it does tee up a mismatch of target setting and monitoring prorgess

Essentially scientists say “we need net zero”, countries say “we’ve got plans to meet net zero”. But different definitions mean they don’t meet in the middle.

But the definition of emissions used by UNFCCC reporting splits “human” and “natural” by _location_. Anything which happens on managed land can be classed as a removal. This means that some of the natural carbon sink is attributed to human activity leading to an overestimate of our removals.

The definition used by IPCC ARs splits “human” and “natural” by _process_. In this case human removals can include planting forests. But NOT the response of existing forests to elevated CO2. Such a response is classed as natural

It is by this definition that net zero leads to stopping warming…

The confusion is how we treat the behaviour of the land carbon sink on land classed as “managed”.

Does stuff here count as “natural” or “anthropogenic”? Different conventions say both yes and no to this - which leads to different measures of human emissions

“net zero” sounds easy – remove as much as we emit. Then global warming stops right?

A thread on how, sadly, it turns out there are differing definitions of “anthropogenic” and hence of net zero. This means we might think we’ve done what’s required to halt warming, but actually we don’t.

COP29: UN climate talks 'no longer fit for purpose' say experts Call for change comes after host country Azerbaijan's president calls oil and gas a 'gift of God'

‘At the last COP, fossil fuel lobbyists outnumbered representatives of scientific institutions, Indigenous communities and vulnerable nations’ C Figueres (ex UN) . We don’t have time for this corrupt and inept fiasco - we are being failed www.bbc.com/news/article...

The global carbon budget 2024 is out

my first bluesky mention :-) cool paper Ben!