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The Final 25% project at the Oxford Smith School of Enterprise and the Environment aims to identify the landscape of key technological solutions for the final stages of the essential transition to net-zero, and then net-negative, CO2 emissions.

The underlying premise is that 80% of emissions reduction can be achieved by decarbonising electricity generation, transport, and heating, and improving energy efficiency, using technical solutions which are already the focus of significant research and development. The remaining 20% of global emissions are perceived to be difficult to decarbonise and currently lack clear reduction pathways. Research attention must be directed to these emissions sources now, so that necessary technologies and business models can be developed over time.

Net-zero emissions is unlikely to be enough to stabilise planetary temperature below a 1.5°C temperature rise. It is likely that temperatures will overshoot, and in order to limit climate change repercussions, there is a need to go net-negative and absorb between 2 and 20 Gt CO2 per year by 2100. At the least, this is a further 5% reduction on top of eliminating present-day emissions.

The Final 25% Series focuses on those hard-to-abate sectors, which form the final 20% of emissions, and solutions to achieving 5% net-negative CO2.

As a key input into the project, a series of dinners are convened in Oxford and London. The Oxford dinners, where selected guests include leading scientists, engineers and technologists, focus on the key science and technology Research and Development (R&D) needed to achieve net negative emissions. The London dinners, where guests include leaders from finance, industry and government, explore how these new ideas can be funded and deployed at scale to make a material contribution.

This report series describes the key conclusions from the discussions, offering recommendations based on the insights of experts working closest to these topics. The subjects covered during the ongoing series include, among others:

  1. Nature-based CO2 sinks
  2. Long-term energy storage
  3. The future of cooling
  4. Alternatives to fossil carbon for industrial products and processes
  5. Bankable carbon capture and storage
  6. The climate impact of alternative proteins


Documents & Reports




The Final 25% Series was made possible by generous financial support from Mike Mason and Richard Nourse. We are also grateful to those who supported the publication of the individual reports.