Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Meta-analysis on necessary investment shifts to reach net zero pathways in Europe


Reaching a pathway towards net zero GHG emissions requires rapid and massive investments in low-carbon infrastructure. To redirect finance flows accordingly, particularly the European Union places an emphasis on sustainable finance regulation. However, the specific investment shifts required are not fully understood, which could lead to an insufficient steering effect for crucial technologies. Here we conduct a meta-analysis to derive the required technology-level investment shifts for climate-relevant infrastructure until 2035. We find a steep uptick in overall investment need, with almost €90 billion yr−1 being required already within the very near term (2021–25). Investment shifts are most drastic for power plants, electricity grids and rail infrastructure, which is even increased by the ambitions to become independent from Russian gas imports. Our findings highlight the need for sustainable finance policies that take into account the financing structures of these sectors specifically.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Past investments and future investment needs in Europe.
Fig. 2: Investment shifts required between 2016–20 and 2021–25.
Fig. 3: All data points derived in the meta-analysis.
Fig. 4: Spread of the investment needs.
Fig. 5: Investment needs by type of institutions for five key technologies.
Fig. 6: Increase in investment needs for a reduction of imports of Russian gas.

Similar content being viewed by others

Data availability

All data generated or analysed during this study are included in the article and its Supplementary Information and Data files. Source data are provided with this paper.

Code availability

The code necessary to reproduce the six main figures and the t-test presented in the Supplementary Information is available at Zenodo65 under the identifier


  1. World Energy Outlook 2021 (IEA, 2021);

  2. Granoff, I., Hogarth, J. R. & Miller, A. Nested barriers to low-carbon infrastructure investment. Nat. Clim. Change 6, 1065–1071 (2016).

    Article  Google Scholar 

  3. IPCC. Special Report on Global Warming of 1.5°C (eds Masson-Delmotte, V. et al.) (WMO, 2018).

  4. Steffen, B. A comparative analysis of green financial policy output in OECD countries. Environ. Res. Lett. 16, 074031 (2021).

    Article  Google Scholar 

  5. Renewed Sustainable Finance Strategy and Implementation of the Action Plan on Financing Sustainable Growth (European Commission, 2018);

  6. 2050 Long-term Strategy (European Commission, 2019);

  7. Long-term Climate Strategy to 2050 (Federal Office for the Environment, 2021);

  8. Act Relating to Norway’s Climate Targets (Climate Change Act) (Ministry of Climate and Environment, 2021);

  9. UK Enshrines New Target in Law to Slash Emissions by 78% by 2035 (Department for Business, Energy & Industrial Strategy & Prime Minister’s Office, 2021);

  10. Net Zero by 2050. A Roadmap for the Global Energy Sector (IEA, 2021);

  11. Andrijevic, M., Schleussner, C.-F., Gidden, M. J., McCollum, D. L. & Rogelj, J. COVID-19 recovery funds dwarf clean energy investment needs. Science 370, 298–300 (2020).

    Article  CAS  Google Scholar 

  12. McCollum, D. L. et al. Energy investment needs for fulfilling the Paris Agreement and achieving the Sustainable Development Goals. Nat. Energy 3, 589–599 (2018).

    Article  Google Scholar 

  13. Pietzcker, R. C., Osorio, S. & Rodrigues, R. Tightening EU ETS targets in line with the European Green Deal: impacts on the decarbonization of the EU power sector. Appl. Energy 293, 116914 (2021).

    Article  Google Scholar 

  14. Bogdanov, D. et al. Radical transformation pathway towards sustainable electricity via evolutionary steps. Nat. Commun. 10, 1077 (2019).

    Article  Google Scholar 

  15. Polzin, F., Sanders, M. & Serebriakova, A. Finance in global transition scenarios: mapping investments by technology into finance needs by source. Energy Econ. 99, 105281 (2021).

    Article  Google Scholar 

  16. Recharge EU: How Many Charge Points Will Europe and its Member States Need in the 2020s (Transport & Environment, 2020);

  17. Persson, U., Wiechers, E., Möller, B. & Werner, S. Heat Roadmap Europe: heat distribution costs. Energy 176, 604–622 (2019).

    Article  Google Scholar 

  18. Hof, A. F. et al. From global to national scenarios: bridging different models to explore power generation decarbonisation based on insights from socio-technical transition case studies. Technol. Forecast. Soc. Change 151, 119882 (2020).

    Article  Google Scholar 

  19. Lux, B. & Pfluger, B. A supply curve of electricity-based hydrogen in a decarbonized European energy system in 2050. Appl. Energy 269, 115011 (2020).

    Article  CAS  Google Scholar 

  20. Bogdanov, D. et al. Low-cost renewable electricity as the key driver of the global energy transition towards sustainability. Energy 227, 120467 (2021).

    Article  Google Scholar 

  21. Field, A. P. & Gillett, R. How to do a meta-analysis. Br. J. Math. Stat. Psychol. 63, 665–694 (2010).

    Article  Google Scholar 

  22. Gurevitch, J., Koricheva, J., Nakagawa, S. & Stewart, G. Meta-analysis and the science of research synthesis. Nature 555, 175–182 (2018).

    Article  CAS  Google Scholar 

  23. Child, M., Kemfert, C., Bogdanov, D. & Breyer, C. Flexible electricity generation, grid exchange and storage for the transition to a 100% renewable energy system in Europe. Renew. Energy 139, 80–101 (2019).

    Article  Google Scholar 

  24. Stolz, B., Held, M., Georges, G. & Boulouchos, K. Techno-economic analysis of renewable fuels for ships carrying bulk cargo in Europe. Nat. Energy 7, 203–212 (2022).

    Article  Google Scholar 

  25. Griffiths, S., Sovacool, B. K., Kim, J., Bazilian, M. & Uratani, J. M. Industrial decarbonization via hydrogen: a critical and systematic review of developments, socio-technical systems and policy options. Energy Res. Soc. Sci. 80, 102208 (2021).

    Article  Google Scholar 

  26. Markard, J. The next phase of the energy transition and its implications for research and policy. Nat. Energy 3, 628–633 (2018).

    Article  Google Scholar 

  27. Breyer, C., Fasihi, M., Bajamundi, C. & Creutzig, F. Direct air capture of CO2: a key technology for ambitious climate change mitigation. Joule 3, 2053–2057 (2019).

    Article  Google Scholar 

  28. van Vuuren, D. P. et al. Alternative pathways to the 1.5 °C target reduce the need for negative emission technologies. Nat. Clim. Change 8, 391–397 (2018).

    Article  Google Scholar 

  29. Pastori, E. et al. Research for TRAN Committee—Modal Shift in European Transport: A Way Forward (European Parliament, 2018);

  30. Sustainable and Smart Mobility Strategy—Putting European Transport on Track for the Future (European Commission, 2020);

  31. European Commission. Sustainable and Smart Mobility Strategy – putting European transport on track for the future. Available at (2020).

  32. Haegel, N. M. et al. Terawatt-scale photovoltaics: transform global energy. Science 364, 836–838 (2019).

    Article  CAS  Google Scholar 

  33. Victoria, M. et al. Solar photovoltaics is ready to power a sustainable future. Joule 5, 1041–1056 (2021).

    Article  CAS  Google Scholar 

  34. Renewable Capacity Statistics 2021 (IRENA, 2021);

  35. Transporting Pure Hydrogen by Repurposing Existing Gas Infrastructure: Overview of Existing Studies and Reflections on the Conditions for Repurposing (European Union Agency for the Cooperation of Energy Regulators, 2021).

  36. Steffen, B. & Patt, A. A historical turning point? Early evidence on how the Russia–Ukraine war changes public support for clean energy policies. Energy Res. Soc. Sci. 91, 102758 (2022).

    Article  Google Scholar 

  37. Lau, M., Ricks, W., Patankar, N. & Jenkins, J. Pathways to European independence from Russian natural gas. Zenodo (2022).

  38. Pedersen, T. T., Gøtske, E. K., Dvorak, A., Andresen, G. B. & Victoria, M. Long-term implications of reduced gas imports on the decarbonization of the European energy system. Joule 6, 1566–1580 (2022).

    Article  CAS  Google Scholar 

  39. Does Phasing-out Russian Gas Require New Gas Infrastructure? (Artelys, 2022);

  40. EU’s Russian Gas Phase-Out Hinges on Clean Energy (Bloomberg, 2022).

  41. Financing REPowerEU (European Commission, 2022);

  42. Steffen, B. The importance of project finance for renewable energy projects. Energy Econ. 69, 280–294 (2018).

    Article  Google Scholar 

  43. Henderson, M. in The Principles of Project Finance (ed. Morisson, R.) 185–204 (Routledge, 2016).

  44. Global Trends in Renewable Energy Investment 2020 (Frankfurt School-UNEP Centre & BNEF, 2020);

  45. Report on Regulatory Frameworks for European Energy Networks 2020 (Council of European Energy Regulators, 2021);

  46. The Regulatory Asset Base and Project Finance Models. An Analysis of Incentives for Efficiency (OECD, 2016);

  47. Ameli, N., Kothari, S. & Grubb, M. Misplaced expectations from climate disclosure initiatives. Nat. Clim. Change 11, 917–924 (2021).

    Article  Google Scholar 

  48. Mazzucato, M. & Semieniuk, G. Financing renewable energy: who is financing what and why it matters. Technol. Forecast. Soc. Change 127, 8–22 (2018).

    Article  Google Scholar 

  49. The European Green Deal Investment Plan and Just Transition Mechanism Explained (European Commission, 2020);

  50. >€1 Trillion for <1.5°C. Climate and Environmental Ambitions of the European Investment Bank Group (European Investment Bank, 2020);

  51. Climate Action and Environmental Sustainability: Overview 2021 (European Investment Bank, 2021);

  52. Climate Action and Environmental Sustainability: Overview 2022 (European Investment Bank, 2022);

  53. Climate Action and Environmental Sustainability: Overview 2020 (European Investment Bank, 2020);

  54. Steffen, B. & Schmidt, T. S. A quantitative analysis of 10 multilateral development banks’ investment in conventional and renewable power-generation technologies from 2006 to 2015. Nat. Energy 4, 75–82 (2019).

    Article  Google Scholar 

  55. EIB Group Climate Bank Roadmap 2021–2025 (European Investment Bank, 2020);

  56. Geddes, A., Schmidt, T. S. & Steffen, B. The multiple roles of state investment banks in low-carbon energy finance: an analysis of Australia, the UK and Germany. Energy Policy 115, 158–170 (2018).

    Article  Google Scholar 

  57. Egli, F., Steffen, B. & Schmidt, T. S. A dynamic analysis of financing conditions for renewable energy technologies. Nat. Energy 3, 1084–1092 (2018).

    Article  Google Scholar 

  58. Kempa, K., Moslener, U. & Schenker, O. The cost of debt of renewable and non-renewable energy firms. Nat. Energy 6, 135–142 (2021).

    Article  Google Scholar 

  59. Riahi, K. et al. Cost and attainability of meeting stringent climate targets without overshoot. Nat. Clim. Change 11, 1063–1069 (2021).

    Article  Google Scholar 

  60. Seto, K. C. et al. Carbon lock-in: types, causes, and policy implications. Annu. Rev. Environ. Resour. 41, 425–452 (2016).

    Article  Google Scholar 

  61. Technical Note on Estimates of Infrastructure Investment Needs. Background Note to the Report Investing in Climate, Investing in Growth (OECD, 2017);

  62. Scopus. Expertly Curated Abstract & Citation Database (Elsevier, 2022);

  63. EU Action (European Commission, 2021);

  64. Tapio, P. Towards a theory of decoupling: degrees of decoupling in the EU and the case of road traffic in Finland between 1970 and 2001. Transp. Policy 12, 137–151 (2005).

    Article  Google Scholar 

  65. Klaaßen, L. & Steffen, B. Meta-analysis on necessary investment shifts to reach net zero pathways in Europe. Zenodo (2022).

Download references


L.K. and B.S. have received funding from the EU Horizon 2020 research and innovation programme, European Research Council (grant agreement no. 948220, project no. GREENFIN) for this project. The compilation of the database and the plotting of the results were supported by F. Hafner, N. Knecht, G. Mancini and M. Prébandier.

Author information

Authors and Affiliations



B.S. and L.K. developed the research idea. L.K. compiled and analysed the data. L.K. and B.S. interpreted the results and wrote the paper. B.S. secured project funding.

Corresponding authors

Correspondence to Lena Klaaßen or Bjarne Steffen.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Climate Change thanks Johannes Schmidt, Kyle Herman and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Text, Figs. 1–12, Tables 1–10 and refs. 1–71.

Supplementary Data 1

Literature overview; Data analysis; Extended analysis—Russian gas phase out.

Supplementary Data 2

PRISMA checklist.

Source data

Source Data Fig. 1

Statistical source data.

Source Data Fig. 2

Statistical source data.

Source Data Fig. 3

Statistical source data.

Source Data Fig. 4

Statistical source data.

Source Data Fig. 5

Statistical source data.

Source Data Fig. 6

Statistical source data.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Klaaßen, L., Steffen, B. Meta-analysis on necessary investment shifts to reach net zero pathways in Europe. Nat. Clim. Chang. 13, 58–66 (2023).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing