Residual emissions in long-term national climate strategies show limited climate ambition

[Geoengineering News]

https://www.cell.com/one-earth/fulltext/S2590-3322(24)00199-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2590332224001994%3Fshowall%3Dtrue

Authors 

Harry B. Smith, Naomi E. Vaughan, Johanna Forster 

Published: May 09, 2024

DOI:https://doi.org/10.1016/j.oneear.2024.04.009

Highlights

•Residual emissions average 21% of peak emissions for Annex I countries

•By sector, agriculture represents the largest contributor to residual emissions

•High-residual scenarios show how some countries may retain more fossil fuels

Science for society

Net-zero targets are now the guiding principle of climate policy. The “net” of these targets implies the need to remove carbon dioxide from the atmosphere to compensate for a level of continuing emissions. These emissions are commonly called “residual emissions” and are expected to represent “hard-to-abate” sources, which have barriers to reducing their emissions. We explore 71 long-term national climate strategies to understand the level and distribution of residual emissions. We find that 41 do not include an estimate or include only short-term emissions modeling, meaning they do not estimate residual emissions. For strategies that do, these emissions are on average one-fifth of developed countries’ peak emissions and mainly consist of emissions from agriculture. High-residual-emission scenarios show how some countries may retain or expand their fossil fuel production and use, using more carbon dioxide removal to achieve net zero.

Summary

Net-zero targets imply a need to compensate for residual emissions through the deployment of carbon dioxide removal methods. Yet the extent of residual emissions within national climate plans, alongside their distribution, is largely unexplored. Here, we analyze 71 long-term national climate strategies to understand how national governments engage with residual emissions. Screening 139 scenarios, we determined that only 26 of the 71 strategies quantify residual emissions. Residual emissions are on average 21% of peak emissions for Annex I countries, ranging from 5% to 52% (excluding land use). For non-Annex I countries, residual emissions are on average 34%. By sector, agriculture represents the largest contributor to total residual emissions (on average, 36% for Annex I countries and 35% for non-Annex I countries). High-residual-emission scenarios show how some countries may retain or expand their fossil fuel production and use, using more carbon dioxide removal or international offsets to achieve net zero.

Graphical abstract

Source: OneEarth