Workshop Detection and Attribution of Climate Engineering

3 – 5 December 2018, Hamburg, Elsa-Brandström-Haus (

More information here ...

Our animation film is now available on youtube: Ambitious climate targets – the role of negative emissions

3. SPP 1689 Retreat / September 2018

3rd & last annual retreat of the SPP1689/2
26. - 28. September Schloss Buchenau

New SPP 1689 Publications

Video Impression from the SPP 1689 & ISOS Workshop on Science Communication

A video by Zhihong Zho // July 2018 // Travemünde

Updated versions of our information graphics on Climate Engineering ideas

The infographics are licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.

Contrails vs Chemtrails

Young Scientist Retreat & Workshop 2018

The SPP 1689 Young Scientist Retreat & Workshop on Interdisciplinary Exchange took place in the Landhaus Lenzener ElbtalaueApril 23-25.

Some impressions

SPP 1689 citizen's jury

The DFG project TOMACE, one of the projects within the SPP 1689 »Climate Engineering«, started in January his citizen's jury. Participation was only possible by invitation.

More informations
Some impressions

New SPP 1689 Publications

  • Ferrer González, Miriam, Tatiana Ilyina, Sebastian Sonntag, Hauke Schmidt (2018): Enhanced Rates of Regional Warming and Ocean Acidification after Termination of Large‐scale Ocean Alkalinization, Geophysical Research Letters, doi: 10.1029/2018gl077847
  • Keller, D.P., Lenton, A., Littleton, E.W. et al. (2018): The Effects of Carbon Dioxide Removal on the Carbon Cycle, Curr Clim Change Rep, 1-16,
  • Kriegler, M., G. LudererN. BauerL. BaumstarkS. FujimoriA. PoppJ. RogeljJ. Strefler, . P. van Vuuren (2018): Pathways limiting warming to 1.5°C: a tale of turning around in no time?, 
  • Oliveira-Garcia, W., T. Amann, J. Hartmann (2018): Increasing biomass demand enlarges negative forest nutrient budget areas in wood export regions, Scientific Reports 8 (5280), doi:10.1038/s41598-018-22728-5
  • Ott, K. K. (2018): On the Political Economy of Solar Radiation Management, Frontiers in Environmental Science 6, 43,
  • Rickels, W., Reith, F., Keller, D., Oschlies, A., & Quaas, M. F. (2018): Integrated Assessment of Carbon Dioxide Removal, Earth’s Future, 6.
  • Roshan, E., M. M. Khabbazan & H. Held (2018): Cost-Risk Trade-Off of Mitigation and Solar Geoengineering: Considering Regional Disparities Under Probabilistic Climate Sensitivity,  Environ. Resource Econ., 1-17,
  • Strefler, Jessica; et al. (2018): Between Scylla and Charybdis: Delayed mitigation narrows the passage between large-scale CDR and high costs, Environmental Research Letters, 13. 044015.
  • Werner, C., H-P. SchmidtD. GertenW. Lucht and C. Kammann (2018): Biogeochemical potential of biomass pyrolysis systems for limiting global warming to 1.5 °C, Environmental Research Letters 13 (4),

CDRMIP has been endorsed by CMIP6

The Coupled Model Intercomparison Project (CMIP; currently in it's 6th phase) is organized under the auspices of the World Climate Research Programme (WCRP) and designed to better understand past, present, and future climate change through coordinated international multi-model experiments that have become a central element of national and international assessments of climate change, e.g., IPCC reports.  The Carbon Dioxide Removal Model Intercomparison Project (CDRMIP), which has just been endorsed by CMIP6, brings together models of the Earth system in a common framework to explore the potential, impacts, and challenges of Carbon Dioxide Removal (CDR).  CDRMIP experiments are designed to address questions concerning CDR-induced climate "reversibility", the response of the Earth system to direct atmospheric CO2 removal (direct air capture and storage), and the CDR potential of proposed schemes such as afforestation/reforestation and ocean alkalinization.    

World Climate Research Program:



New SPP 1689 Publications

  • Keller, D. P., Lenton, A., Scott, V., Vaughan, N. E., Bauer, N., Ji, D., Jones, C. D., Kravitz, B., Muri, H., and Zickfeld, K.: The Carbon Dioxide Removal Model Intercomparison Project (CDR-MIP): Rationale and experimental protocol for CMIP6, Geosci. Model Dev.,, 2018
  • Kleinschmitt, C., Boucher, O., and Platt, U. (2018): Sensitivity of the radiative forcing by stratospheric sulfur geoengineering to the amount and strategy of the SO2injection studied with the LMDZ-S3A model, Atmos. Chem. Phys., 18, 2769-2786,
  • Oschlies, Andreas (2018): Solar engineering must take temperature debt into account, Nature 554, 423,
  • Mengis, N., Keller, D. P., and Oschlies, A. (2018): Systematic Correlation Matrix Evaluation (SCoMaE) – a bottom–up, science-led approach to identifying indicators, Earth Syst. Dynam., 9, 15-31,
  • Keller D.P. (2018) Marine Climate Engineering. In: Salomon M., Markus T. (eds) Handbook on Marine Environment Protection. Springer, Cham, doi:10.1007/978-3-319-60156-4_13
  • Strefler, Jessica; et al. (2018): Potential and costs of carbon dioxide removal by enhanced weathering of rocks
  • Sonntag, Sebastian; et al. (2018): Quantifying and comparing effects of climate engineering methods on the Earth system, Earth's Future, doi:10.1002/2017EF000620
  • Heck, Vera; et al. (2018): Biomass-based negative emissions difficult to reconcile with planetary boundaries, Nature Climate Change (2018), doi:10.1038/s41558-017-0064-y

SPP 1689 Workshop Terrestrial CO2 Removal

SPP 1689 WORKSHOP // 22 – 23 Jan 2018 // Potsdam Institute for Climate Impact Research, A56

Terrestrial CO2 Removal: Potentials and tradeoffs in the SDG context

This workshop will look into a set of pertinent questions related to potentials of tCDR methods and their interaction with SDGs. It will bring together SPP 1689 researchers and external experts to increase our holistic understanding of global and regional potentials and side-effects of tCDR as well as to identify future research priorities.
read more and find the agenda here ...

New Publications

Niemeier, U. and Schmidt, H. (2017): Changing transport processes in the stratosphere by radiative heating of sulfate aerosols, Atmos. Chem. Phys., 17, 14871-14886,

Feng, E. Y.; Koeve, W.; Keller, D. P. and Oschlies, A. (2017): Model-based Assessment of the CO2 Sequestration Potential of Coastal Ocean Alkalinization. In Earth's Future. DOI: 10.1002/2017EF000659.

New Publication

Ferrer-Gonzalez, M. (2017). Climate engineering by enhancement of ocean alkalinity: impacts on the Earth system and a comparison with solar radiation management. PhD Thesis, Universität Hamburg, Hamburg. doi:10.17617/2.2472753.

German Science Hour im Deutschen Pavillion auf der COP 23

Andreas Oschlies, Mark Lawrence, Oliver Geden and Lilly Fuhr: “Failing the carbon budget - what's next?” (Photo)

SPP 1689 Workshop Climate Engineering Regulation and Liability

16 – 18 October 2017, KIEL

Some photographs, more information and the agenda here (english only) ...

New SPP 1689 Publications

  • Kemena,Tronje Peer; Matthes, Katja; Martin, Thomas; Wahl, Sebastian; Oschlies, Andreas: Atmospheric feedbacks in North Africa from an irrigated, afforested Sahara, Clim Dyn (2017).
  • Keller, D. P., Lenton, A., Scott, V., Vaughan, N. E., Bauer, N., Ji, D., Jones, C. D., Kravitz, B., Muri, H., and Zickfeld, K.: The Carbon Dioxide Removal Model Intercomparison Project (CDR-MIP): Rationale and experimental design, Geosci. Model Dev. Discuss.,, in review, 2017.

Overview on modelling in the SPP 1689


Climate Engineering Conference 2017

October 9 -12, 2017, Berlin

Klimaschutz braucht mehr Forscher und Erfinder
// Weniger Emissionen allein reichen nicht: Der Atmosphäre muss CO2 entzogen werden / Von Andreas Mihm

Wilfried Rickels u.a. im Artikel auf (german):

New SPP 1689 Publications

  • Niemeier, Ulrike, Tilmes, Simone: Sulfur injections for a cooler planet, Science 21 Jul 2017, Vol. 357, Issue 6348, pp. 246-248, DOI: 10.1126/science.aan3317,

  • Lohmann, Ulrike, Gasparini, Blaž: A cirrus cloud climate dial?, Science 21 Jul 2017, Vol. 357, Issue 6348, pp. 248-249, DOI: 10.1126/science.aan3325,
  • Kleinschmitt, C., Boucher, O., and Platt, U.: Sensitivity of the radiative forcing by stratospheric sulfur geoengineering to the amount and strategy of the SO2 injection studied with the LMDZ-S3A model, Atmos. Chem. Phys. Discuss.,, in review, 2017.

  • Stelzer, Harald (2017): Justifying Climate Engineering?. In: Jahrbuch für Wissenschaft und Ethik. Band 21 (2016). Berlin: De Gruyter, 147–169.

2nd SPP 1689 Retreat / Summer 2017

July 5-7, 2017 at the Schloss Buchenau near Fulda/Bad Hersfeld.

Impressions of the Retreat here.

New SPP 1689 Publications

Radio Ecoshock

Lena Boysen about »green« climate engineering with trees:

New SPP 1689 Publications

First Young Scientist Retreat of the 2nd Phase

SPP 1689 Young Scientist Retreat in Malente

Impressions here …

New SPP 1689 Publications

Veröffentlichung der Deutschen Meteorologischen Gesellschaft

Die Deutsche Meteorologischen Gesellschaft (DMG) hat eine Stellungnahme und einen kurzen Erläuterungstext zu Climate Engineering in ihren »Mitteilungen« veröffentlicht:

New SPP 1689 Publications

  • Quaas, Martin F.; Quaas, Johannes; Rickels, Wilfried; Boucher, Olivier (2017): Are there reasons against open-ended research into solar radiation management? A model of intergenerational decision-making under uncertainty. In Journal of Environmental Economics and Management. DOI: 10.1016/j.jeem.2017.02.002.

New SPP 1689 Publications

SPP 1689 Workshop on the 1.5°C Target and Climate Engineering

24–25 November 2016 // Kiel // Germany

read more ...


Climate Engineering Ideas

More downloads for your information under DOWNLOADS

This infographic is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.


Is Climate Engineering an option to prevent climate change?

There are many central open questions. More downloads for your information under DOWNLOADS

This infographic is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.

Faltblatt Naturwissenschaftler antworten Journalisten

Einige Naturwissenschaftler aus dem Schwerpunktprogramm SPP 1689 antworten hier  professionellen WissenschaftsjournalistInnen vom „Nationalen Institut für Wissenschaftskommunikation“ (Karls­ruhe) auf konkrete Fragen zu ihrer Wissenschaft.

Hier klicken um zum e-paper »Naturwissenschaftler antworten Journalisten« zu kommen

New SPP 1689 Publications

KlimaTaucher - Fernreisen mit gutem Gewissen? Wie wir das Klima beeinflussen können

DFG-Filmproduktion zu Climate Engineering mit Andreas Oschlies und Nadine Mengis

New SPP 1689 Publications

Ellias Y Feng (冯玉铭), David P Keller, Wolfgang Koeve and Andreas Oschlies (2016): Could artificial ocean alkalinization protect tropical coral ecosystems from ocean acidification? In: Environmental Research Letters, vol. 11, no. 7,

SPP 1689 Retreat Impressions

First SPP 1689 retreat of the 2nd phase.

See more impressions here ...

First SPP 1689 Retreat of the 2nd Phase

14-16 June 2016, Kloster Haydau / Morschen

(project presentations, discussion of action items for the 2nd phase, setting of cross-project topics)

New SPP 1689 Publications

Mengis, Nadine; et al. (2016): Assessing climate impacts and risks of ocean albedo modification in the Arctic. In Journal of Geophysical Research: Oceans, vol. 121, 3

Merk, Christine; Pönitzsch, Gert; Rehdanz, Katrin (2016): Knowledge about aerosol injection does not reduce individual mitigration efforts. In: Environmental Research Letters, vol. 11, no. 5

Start of 2nd phase

Start of 2nd phase of SPP 1689, May 2016.

Project composition here

Lange Nacht der Forschung in Klagenfurt

Die Lange Nacht der Forschung ist der größte Forschungsevent Österreichs. An der Alpen-Adria-Universität und im Lakeside Science & Technology Park werden 74 Stationen und zahlreiche spannende Highlights geboten.

Das Institut für Technik- und Wissenschaftsforschung der Alpen-Adria-Universität Klagenfurt ist mit einem Stand zum Thema Climate Engineering im Rahmen des SPP 1689 vertreten.

Link zur Website

Lange Nacht der Forschung: CE-Video zur auf youtube: Kann man den Klimawandel reparieren?

Workshops with Prof. Dr. Klaus Keller

13th and 14th April 2016

'Metrics in the context of Climate Engineering'
'Uncertainty Quantification in the context of Climate Engineering'

read more ...

New SPP 1689 Publications

  • //// Science to public /// not reviewed /// german:
    Bauer, Stefanie; Matzner, Nils (2016): Zeit, Demokratie und ClimateEngineering. In Zeitpresse (Winter 15/16), pp. 32–34. download here

SPP1689 at the AGU Fall Meeting

Greetings from our SPP 1689 representatives at the AGU Fall Meeting in San Francisco (December 14-18,
2015) at the »Research in Germany« Booth.

Vortrag von Prof. Andreas Oschlies an der TU München

Climate Engineering – Notoperation gegen den Klimawandel

Vortrag von Prof. Dr. Andreas Oschlies, GEOMAR (Helmholtz Zentrum für Ozeanforschung Kiel), presentation in german

16.12.2015, 19:30-21:00 Uhr
Hörsaal 2750, Hauptgeb. der TUM (Arcisstr. 21)

Lesen Sie mehr auf der Seite der TU Müchen

German documentary on CE including interviews with the SPP 1689

SPP 1689 Workshop Report


Link to online version.

New SPP 1689 Publications

Quaas J. (2015): Approaches to Observe Anthropogenic Aerosol-Cloud Interactions. In Curr Clim Change Rep 1 (4), pp. 297–304. DOI: 10.1007/s40641-015-0028-0

Mengis, N., Keller D., Eby, M. and Oschlies, A.: Uncertainty in the response of transpiration to CO2 and implications for climate change,  2015 Environ. Res. Lett. 10 094001, DOI:10.1088/1748-9326/10/9/094001

Aswathy, V. N., Boucher, O., Quaas, M., Niemeier, U., Muri, H., Mülmenstädt, J., and Quaas, J.: Climate extremes in multi-model simulations of stratospheric aerosol and marine cloud brightening climate engineering, Atmos. Chem. Phys., 15, 9593-9610, DOI:10.5194/acp-15-9593-2015, 2015.

SPP 1689 Climate Engineering Research Conference // July 2015

Berlin-Brandenburgische Akademie der Wissenschaften, 7th-10th of July  2015 / Read more in our blog

or see some impressions here

New SPP 1689 Publications

Saxler, Barbara; Siegfried, Jule; Proelß, Alexander (2015): International liability for transboundary damage arising from stratospheric aerosol injections. In Law, Innovation and Technology 7 (1), pp. 112–147. DOI 10.1080/17579961.2015.1052645.
Link to PDF


Kreuter; Judith (2015): Technofix, Plan B or Ultima Ratio? A Review of the Social Science Literature on Climate Engineering Technologies. Oxford University, Institute of Science, Innovation and Society (Occasional Paper Series, 2).
Link to PDF

Heyen, Daniel (2015): Five Essays in the Economics of Climate Engineering, Research, and Regulation under Uncertainty. Dissertation. Ruprecht-Karls-Universität, Heidelberg. Economy and Social Sciences.
Link to PDF

Science and Responsibility

Leaflet with impressions from the analysis of the SPP 1689 within the sub-project SciPol (german).

Click here to go to the german e-paper »Wissenschaft und Verantwortung«

New SPP 1689 Publications

Ilyina, T. (2015). The combined effects of changes in ocean chemistry, biology, and hydrodynamics on alkalinity. Nova Acta Leopoldina NF, 121(No. 408 - Deglacial Changes in Ocean Dynamics and Atmospheric CO2)
Link to PDF

Ferrer-Gonzalez, Miriam; Ilyina, Tatiana (2015): Mitigation Potential, Risks, and Side-Effects of Ocean Alkalinity Enhancement. In Nova Acta Leopoldina 121 (408), pp. 275–278.
"The novelty of our research relies on the fact that none of previous studies have addressed this topic with a fully coupled Earth system model of such a level of complexity. Fully coupled set-ups (versus box-models or forced subsystems) hold the potential of revealing new features within the Earth system dynamics."
Link to PDF

Vivian Scott, R. Stuart Haszeldine, Simon F. B. Tett, Andreas Oschlies
Nature Climate Change 5, 419-423 (2015), doi:10.1038/nclimate2578
Link to

Sillmann, J.; et al. (2015): Climate emergencies do not justify engineering the climate
"Current climate engineering proposals do not come close to addressing the complex and contested nature of conceivable 'climate emergencies' resulting from unabated greenhouse-gas emissions."
Link to Nature Climate Change

Niemeier, U.; Timmreck, C. (2015): What is the limit of stratospheric sulfur climate engineering?
"The injection of sulfur dioxide (SO2) into the stratosphere to form an artificial stratospheric aerosol layer is considered as an option for solar radiation management. The related reduction in radiative forcing depends upon the amount injected of sulfur dioxide but aerosol model studies indicate a decrease in forcing efficiency with increasing injection magnitude."
Link to Atmospheric Chemistry and Physics

Matzner, Nils (2015): Engineering the Climate. Politik und Planung der Klimaintervention. In Matthias Koch, Christian Köhler, Julius Othmer, Andreas Weich (Eds.): Planlos! Zu den Grenzen von Planbarkeit. 1st ed. Paderborn: Fink, Wilhelm, pp. 165–179.
German book chapter on climate engineering and its implications and problems of planning.
Link (


Harnisch, Sebastian; Uther, Stephanie; Böttcher, Miranda (2015): From 'Go Slow’ to ‘Gung Ho’? Climate Engineering Discourses in the UK, the US, and Germany. In Global Environmental Politics 15 (2), pp. 57–78. DOI 10.1162/GLEP_a_00298
Link to mitpressjournals

Merk, Christine et al., Exploring public perceptions of stratospheric sulfate injection.
Climatic Change, DOI: 10.1007/s10584-014-1317-7
Link to Springer Climatic Change

SPP 1689 Scenario workshop Hamburg

Follow-up to the Kassel retreats breakout sessions:
I Development of Assessment Metrics
III Integrative Approaches to Risk / Technology Assessment
Scenario workshop (PhD students only)

See more ...

SPP 1689 & SPP 1409 Symposium: Uncertainty as a challenge for science

Uncertainty as a challenge for science – natural-, human- and social-sciences perspectives
Georg-Christoph-Lichtenberg-Haus der TU Darmstadt // 2nd - 4th  March 2015

Read more ...

New SPP 1689 Publications

V. N. Aswathy et al. (2014): Climate extremes in multi-model simulations of stratospheric aerosol and marine cloud brightening climate engineering

Read more on our news portal

SPP 1689 Discourse Workshop

Discourse Workshop for PhD Students in the SPP 1689
Thursday, 4th and Friday, 5th of December 2014 in Heidelberg

The workshop for PhD students of the SPP discussed various approaches to discourses of Climate Engineering.

read more

SPP Retreat 2014

Our 2nd SPP-CE-Retreat had taken place 7-8 of July 2014 in Kassel.

Focus of our 2nd SPP-Retreat was on the progress reports of the individual SPP sub-projects, and discussion of further steps on how to achieve our interdisciplinary goals to enable an assessment of Climate Engineering.

Read more and see more …

SPP 1689 PhD retreat Kassel

PhD retreat Kassel & workshop on interdisciplinary communication

see more ...

Summer School on CE 2014 July 28 - Aug 1

As the fifth installment of an annual series, Heidelberg University, Harvard University, and the German Research Foundation Priority Program on Climate Engineering (SPP 1689) are jointly organizing a summer school on the controversies and complexities of Climate Engineering (CE).

Why do researchers disagree about Climate Engineering?
Heidelberg, July 28 – Aug 1, 2014

see more...

Session at AGU Fall Meeting 2014

San Francisco, 15–19 December 2014 // Session no. 1795

Conveners: Piers Forster (University of Leeds), Ben Kravitz (PNNL); Hauke Schmidt (Max Planck Institute for Meteorology) and Simone Tilmes (NCAR)

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Kiel: Kulturnacht am Blücher

Freitag 6.6. / 20:30 Uhr / Autowerkstatt Köppl & Sohn, Esmarchstr. 29, Kiel

Climate Engineering als Notoperation gegen den Klimawandel!
Müssen wir gezielt in das Klima eingreifen?
Veranstaltung im Rahmen der von Schülern der Kieler Hebbelschule organisierten „Kulturnacht am Blücher”:
Kombination aus Informationsvortrag und Diskussionen mit und innerhalb der Zuschauer. Den Zuschauern werden dazu Rollen zugeteilt von Akteuren die weltweit vom Klimawandel betroffen sind.
Vortragende waren Prof. Andreas Oschlies (GEOMAR), Carola Kniebes (IFW) und Christian Baatz (CAU), begleitet von Martin Behrens (Schulprogramm SPP1689).

Lecture Barben

Prof. Dr. Daniel Barben, Alpen-Adria-University Klagenfurt

'Responsibility' and 'Uncertainty' in the Climate Engineering Discourse of Science and Policy Making: Preliminary Results of the Research Project CE-SciPol (DFG Priority Programme 1689)

20 May 14, Tuesday / 10:30- 12:00 h / Venue: GEOMAR westshore building, lecture hall / Düsternbrooker Weg 20 / 24105 Kiel

Read more …

Climate CoLab

MIT (Massachusetts Institute of Technology) Center for Collective Intelligence has just launched its Climate CoLab for 2014. (

This year it includes a contest where participants can propose a solution to the question: "How can research into geoengineering be governed to limit its environmental and political risks?"

European Geosciences Union General Assembly 2014

Vienna | Austria | 27 April – 02 May 2014
Sessions with members of the SPP 1689:

Geoengineering the climate: the way forward?

Panel discussion with

  • Ken Caldeira (Department of Global Ecology, Carnegie Institution)
  • Andreas Oschlies (GEOMAR Helmholtz Centre for Ocean Research Kiel)
  • Mark Lawrence (Institute for Advanced Sustainability Studies, Potsdam)
  • Paul Quinn (School of Civil Engineering and Geosciences, Newcastle University)
  • Krishna Kumar Kanikicharla (Coordinating Lead Author, IPCC Working Group I)

Thu, 01 May, 15:30–17:00 | Room Y1


The fate of added alkalinity in model scenarios of ocean alkalinization

Talk by Miriam Ferrer González and Tatiana Ilyina, Wed, 30 Apr, 11:30–11:45 | Room Y2

SPP 1689 Publication About Climate Engineering in “Nature Communications”

Researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel have now studied with computer simulations the long-term global consequences of several “Climate Engineering” methods. The study is published in the international journal “Nature Communications”.

Read more ...

Link to Nature Communications

SPP 1689 Modelling Workshop Hamburg January 2014

Impressions and agenda


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SPP 1689 PhD Retreat und Training

First annual PhD retreat and training, 22. – 24.09.2013 in Plön

Agenda and impressions


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SPP 1689 Kickoff Meeting Impressions

Priority Programme 1689 "Climate Engineering" kickoff-meeting | Berlin-Brandenburg Academy of Sciences and Humanities | 06|03|20013


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