Oliver Geden Profile picture
Head, Research Cluster Climate Policy and Politics @SWPBerlin /// Fellow @InSIS & @IHS_Vienna /// Vice-Chair @IPCC_CH AR7 Working Group III
☀️ Leon-Gerard Vandenberg 🇳🇱🇨🇦🇦🇺 Math+e/acc Profile picture Mark Trexler Profile picture 2 subscribed
Mar 31, 2023 15 tweets 13 min read
As promised, now more on the topics I was deeply involved in as #IPCC #AR6 Synthesis Report author, both in the Summary for Policymakers & the so-called 'Longer Report':
overhoot, net zero, mitigation pathways (incl. CDR)

Let's start with "Overshoot" (B.7), where I was responsible for drafting and 'negotiating' in plenary, but of course not alone (mainly together with @chrisd_jones, with whom I worked on corresponding section 3.3.4 in underlying report)
Mar 20, 2023 4 tweets 2 min read
Unfortunately, the UN Secretary General still doesn't understand difference betw net-zero CO2 and much more ambitious net-zero GHG targets. The famous 2050 is net-zero CO2 for 1.5C, net-zero GHG only some decades later, as per #IPCC WG3 & Synthesis Report
politico.eu/article/climat… UN Secretary General has been ill-advised by his own high-level expert group on net-zero, which also confuses net-zero CO2 and net-zero GHG.
Mar 20, 2023 16 tweets 18 min read
After 3 yrs of hard work & a long approval plenary, we got the #IPCC #AR6 Synthesis Report published today, consisting of the Summary for Policymakers and a full report version ➡️ ipcc.ch/report/ar6/syr/
An ongoing 🧵, starting with SPM fig 1 on adverse climate change impacts
1/n Every increment of warming matters (SPM.2)
Jan 19, 2023 35 tweets 25 min read
Today we publish the 1st edition of the "State of Carbon Dioxide Removal" report, a global assessment of the current #StateofCDR, and the gap we need to close to achieve the Paris temperature goal.
Full report➡️stateofcdr.org
An ongoing 🧵
[1] This report compiles a first estimate of the total CDR being deployed (2 GtCO2/yr).
Almost all comes from "conventional" CDR on land, via afforestation, reforestation & forest management.
"Novel" methods don’t contribute much yet.
Nov 8, 2022 14 tweets 12 min read
The @UN #HLEGReport on Net-zero Emissions Committments is out
The problem though: #IPCC 1.5C pathways don't reach net zero GHG emissions by "2050 or sooner", but by the end of the century. The famous "net zero by 2050" (better "early 2050s) is CO2 only
1/ You might be in disbelief, but have a look at the #IPCC AR6 WG3 Summary for Policymakers, Table SPM.2:
For 1.5C with no or limited overshoot (category C1), pathways reach net-zero CO2 in 2050-2055, but net-zero GHG in 2095-2100
Apr 11, 2022 6 tweets 7 min read
➡️Only 6 out of 97 scenarios in the #IPCC #AR6 WG3 category C1 ('no to limited overshoot') never cross 1.5C
➡️91 out of 97 cross 1.5C temporarily, and then go back to 1.5°C by 2100

If you read the Summary for Policymakers of IPCC AR6 WG1 (Aug. 2021), this cannot come as surprise Below the numbers from #IPCC #AR6 WG1. Not sure if this knowledge was conciously included in "keeping 1.5C alive and within reach" messaging around #COP26.
'Overshoot' pathways (= exceedance & return) didn't make it onto the high-level #UNFCCC agenda yet
Apr 4, 2022 50 tweets 36 min read
The #IPCC #AR6 WG3 report includes a comprehensive assessment of Carbon Dioxide Removal (CDR), its role in mitigation strategies and long-term pathways, but also a techno-economic assessment of ~10 CDR methods
An ongoing 🧵
[1/n] Image For Carbon Dioxide Removal, it's still early days in #climate policy, although there are already established methods (mainly forestry-related and soil carbon sequestration, not necessarily done to remove CO2)
In #AR6 reports, there aren't chapters dealing solely with CDR
Apr 4, 2022 9 tweets 10 min read
#IPCC #AR6 Working Group III SPM and Full Report on "Mitigation of Climate Change" is now available
🧵on key figures and tables from Summary for Policymakers
#ClimateReport Image Key figures & tables from the #IPCC #AR6 WG III Summary for Policymakers
SPM.1: Global net anthropogenic GHG emissions (GtCO2-eq yr-1) 1990–2019
#ClimateReport Image
Mar 21, 2022 9 tweets 7 min read
Today, we'll enter the long but final stretch for #IPCC #AR6 WG III report on mitigation - the virtual approval session, finalizing the 'Summary for Policymakers' (SPM) with governments Full Report and SPM to be published on April 4
Some insights...
ipcc.ch/meeting-doc/ip… [1/n] First WG IIl lead author meeting took place 3 years ago, the process in itself way earlier. There've been delays because of #COVID19, but "Final Draft Report" has been submitted already in Nov 2021. The last months of work have been mainly about SPM
Oct 29, 2021 10 tweets 9 min read
How will climate negotiators deal with diminishing carbon budget for 1.5C?
Some thoughts from our recent @OneEarth_CP paper "#UNFCCC must confront the political economy of net-negative emissions"
Now available #OpenAccess for 2 months
cell.com/one-earth/full… #COP26
(1/n) Paper led by @aniruddh_mohan, co-authored with @MathiasFridahl, @hollyjeanbuck & @Peters_Glen
cell.com/one-earth/full… #COP26
Oct 29, 2021 4 tweets 5 min read
Remarkable framing shift ahead of #COP26

While "close to 1.5C" is politically more plausible than "limit to 1.5C", it's quite ambiguous, similarly to already established "well below 2C"

Is this the new language incorporating (initial) overshoot of 1.5C?

politico.eu/article/why-th… Some background on #IPCC WG1 projections for threshold 1.5C crossing times under different scenarios, explained by @hausfath for @CarbonBrief
Aug 9, 2021 15 tweets 15 min read
IPCC #AR6 WGI report on the physical science basis of climate change is out today.
Find the the Summary for Policymakers and the Full Report here ipcc.ch/report/ar6/wg1/
[1/n] Here's a short thread on Carbon Dioxide Removal, and how the #IPCC #AR6 WGI assessment (led by @KirstenZickfeld) relates to the WGIII report (due in March 2022)
Jul 14, 2021 5 tweets 4 min read
Finally, here's @EU_Commission's #Fitfor55 package, to adjust EU #climate policy legislation to move from original 40% reduction target to 55% by 2030 (vs 1990)
Remember: these are only proposals, decision eventually to be made by @EUCouncil & @Europarl_EN ec.europa.eu/info/strategy/… Image detailed #Fitfor55 proposals to be found at bottom of the page ec.europa.eu/info/strategy/…
Jun 15, 2021 6 tweets 6 min read
The inconvenient truth about the #renewables boom in a world of growing energy consumption. Share of fossil fuels basically unchanged 2009-2019.
From @REN21's new 'Renewables 2021 Global Status Report'
ren21.net/reports/global… The 11.2% #renewables share excludes so-called 'traditional biomass' (e.g., wood for cookstoves). Even then, share of #bioenergy among renewables still considerable
From @REN21's new 'Renewables 2021 Global Status Report'
Jan 27, 2021 6 tweets 4 min read
A crucial aspect still unclear in Biden administration's #climate policy plan. Does "net-zero economy by 2050" cover all greenhouse gases (like in EU) or only CO2 (like US 2035 target for power sector)?
Net-zero GHG is much more ambitious than net-zero CO2
whitehouse.gov/briefing-room/… Net zero GHG is much harder to achieve than net zero CO2. In global scenarios, it takes 10-20 years longer
Oct 22, 2020 7 tweets 7 min read
Major step forward for German #climate debate today, with study from @Prognos_AG, @oekoinstitut & @Wupperinst, The first report on net zero GHGs based on sound modelling
A quick look at Carbon Dioxide Removal
@AgoraEW, @agoraverkehr @StiftungKlima
[1/n] Study assumes 95% conventional mitigation, making it one of the more ambitious for industrialized countries (CCC for UK & COM for EU: ~90%, see swp-berlin.org/10.18449/2020R…)
Residual emissions mainly from agriculture & industry, aviation already at zero
Oct 5, 2020 7 tweets 7 min read
Good that Fridays for Future activists start dealing more and more with the nitty-gritty details of EU #climate policymaking. But with several factual errors and questionable claims in this article, they are risking their credibility.
A short thread [1/n] #EUClimateLaw You can of course criticize EU #climate policy for not being ambitious enough, but claiming that "the EU is cheating with numbers" needs to be backed up with very strong arguments.
[2/n] #EUClimateLaw
Sep 23, 2020 6 tweets 3 min read
Certainly a major step forward that China now aims to achieve 'carbon neutrality' by 2060, but it can't be directly compared to EU's and UK's targets for 'climate neutrality' by 2050.
Net zero GHG harder to achieve than net zero CO2, takes 10-20 yrs more
bbc.com/news/science-e… The main reason is that non-CO2 emissions like nitrous oxide (N20) and methane (CH4) are much harder or impossible to mitigate, so they'll need to be offset by CO2 removal, which takes longer. Below global pathways. For countries, it depends on their specific emissions profile
Sep 19, 2020 8 tweets 6 min read
A bit disturbing that #showyourbudgets contributes to ongoing confusion abt net-zero targets
Net zero CO2 ≠ net zero GHG ('climate neutral'), the latter reached 10-20 yrs later in scenarios due to harder-to-abate non-CO2, offset by CDR
National targets usually set in GHG not CO2 As you can see in global #IPCC pathways, most of the residual emissions at the time of net-zero (and later) are non-CO2, mainly methane and nitrous oxide from agriculture
swp-berlin.org/10.18449/2020R… Image
Sep 17, 2020 6 tweets 4 min read
EU #Climate Target Plan 2030 and accompanying impact assessment now out
ec.europa.eu/clima/policies… Image Scanning for removals-related issues in #EU2030 impact assessment...
This - creating an AFOLU pillar (LULUCF + agricultural non-CO2 emissions) - seems a sensible approach. Could help to clearly distinguish roles of ecosystem-based & technological CO2 removal in EU #climate policy Image
Sep 14, 2020 5 tweets 3 min read
Leaked #EU2030 #climate target plan indicates that @EU_Commission wants to fully integrate LULUCF into target accounting and enhance land-use and forestry sink t by 2030.
A sensible step, but it gives EU ~5 percentage points on the 2030 balance sheet without additional action Image We anticipated this move already in our SWP Research Paper "Unconventional Mitigation: Carbon Dioxide Removal as a New Approach in EU Climate Policy"
swp-berlin.org/10.18449/2020R… Image