Briefing Note 3 – How Much Can We Reduce Emissions Using Currently Available Approaches?


How Fast Can We Transform Global Energy Systems?


While conventional theory on transitions suggests these are long affairs that span decades, islands present a unique opportunity for rapid transitions. This is because the challenges that slow down transitions, such as the scalability issues and market requirements, are not as problematic on islands. Instead, islands offer a ‘niche’ that can serve as an early test bed for rapid emissions reductions. 


From potentially very fast transitions in the case of islands, to much slower transitions in terms of global-scale adoption of ecosystem restoration pathways and other CO2 utilisation solutions, it is important to note that not all solutions are equal in terms of the speed with which they can deliver emissions reductions. Ecosystem restoration pathways are a major component of the One Earth climate model and accompanying book, entitled Achieving the Paris Climate Agreement. 


The One Earth model meets the Paris Agreement’s target of 1.5°C without the use of geoengineering while protecting 50% of lands and oceans. Natural climate solutions (NCS), such as forest ecosystem restoration, sustainable use of forests and agroforestry, are shown to be imperative for keeping global temperature rise to no more than 1.5°C by removing 400 GtCO2 by the end of the century.


At What Scale Are We Able to Reduce Emissions?


The scale of emissions reduction potential is highly variable and context specific. In the case of global scale CO2 utilisation, there is potential for gigaton-scale utilisation by 2050, but there are still major uncertainties in costs, technology development and scalability. 


CO2 utilisation is a process in economically valuable products are generated using CO2, whether that CO2 is supplied from flue gases, captured from the atmosphere via industrial processes or captured from the atmosphere via industrial processes such as photosynthesis or enhanced weathering.


Returning to the small-scale cases of islands such as Mauritius, Fiji, and Barbados, emissions reductions are constrained by factors such as tourism, which can account for 30 to 80% of CO2 emissions on islands. 


However, there is still scope to mitigate the impact of tourism, for example, through optimizing rural transit networks, and this is an active area of research for island transitions. But can these lessons also inform solutions at larger scales? The question of scale is centrally important in how we accelerate and govern transitions.


How Does Governance Influence Ecosystem Restoration Pathways?


In the case of ecosystem restoration pathways, especially those that rely on considerable forest conservation, governance issues are centrally important. Recent work has shown that 40% of protected lands and high-biodiversity conservation areas are managed by indigenous peoples, and if the definition is broadened to include community-held and collectively managed lands, the total is around 60% of the earth’s land surface. 


Respecting and legally recognising indigenous land title is essential. There clearly remains work to be done in quantifying indigenous land management, representing this accurately in models, and further elevating indigenous knowledge and views in the conversation on climate change and emissions reduction pathways.


Governance issues were also identified as critical for large-scale CO2 utilisation efforts. Many of the highlighted techniques show promise for delivering net zero, but this is not an inevitable outcome of their deployment.


CO2 utilisation could have unintended consequences, such as increasing CO2 emissions (e.g. enhanced oil recovery), reducing CO2 emissions without removing CO2 from the atmosphere on a net basis (e.g. synthetic fuels), or having no net impact on CO2 but increasing other greenhouse gas emissions (e.g. synthetic urea). Land governance issues are also relevant in the case of land-based CO2 utilisation pathways, especially bioenergy with carbon capture and storage (BECCS) and reforestation.

What Does Achieving Net Zero Conclude and Recommend?


  • The first and most important thing to concentrate on is reducing emissions. This will always be easier than recapturing what has already been emitted

  • Natural climate solutions have a great deal to offer in terms of carbon sequestration, in addition to restoring and maintaining ecosystem health

  • The main challenge facing us now is political, not technological. We must identify the political pathways for a more rapid transition to net zero

  • Lessons can be learned from energy transition pathways at small scales, such as in island states

  • Governance issues, especially those related to indigenous land management, are vitally important for a just transition