Critical adjustment of land mitigation pathways for assessing countries’ climate progress

Mitigation pathways by Integrated Assessment Models (IAMs) describe future emissions that keep global warming below specific temperature limits and are compared with countries’ collective greenhouse gas (GHG) emission reduction pledges. This is needed to assess mitigation progress and inform emission targets under the Paris Agreement. Currently, however, a mismatch of ~5.5 GtCO2 yr−1 exists between the global land-use fluxes estimated with IAMs and from countries’ GHG inventories. Here we present a ‘Rosetta stone’ adjustment to translate IAMs’ land-use mitigation pathways to estimates more comparable with GHG inventories. This does not change the original decarbonization pathways, but reallocates part of the land sink to be consistent with GHG inventories. Adjusted cumulative emissions over the period until net zero for 1.5 or 2 °C limits are reduced by 120–192 GtCO2 relative to the original IAM pathways. These differences should be taken into account to ensure an accurate assessment of progress towards the Paris Agreement.

GRASSI Giacomo;  STEHFEST Elke;  ROGELJ Joeri;  VAN VUUREN Detlef;  CESCATTI Alessandro;  HOUSE Jo;  NABUURS G. J.;  ROSSI Simone;  ALKAMA Romain;  ABAD VIÑAS Raúl;  CALVIN Katherine V.;  CECCHERINI Guido;  FEDERICI Sandro;  FUJIMORI Shinichiro;  GUSTI Mykola;  HASEGAWA Tomoko;  HAVLIK Petr;  HUMPENÖDER Florian;  KOROSUO Anu;  PERUGINI Lucia;  TUBIELLO Francesco;  POPP Alexander; 

2021-05-28

NATURE PUBLISHING GROUP

JRC124333

1758-678X (online),   

https://www.nature.com/articles/s41558-021-01033-6,    https://publications.jrc.ec.europa.eu/repository/handle/JRC124333,   

10.1038/s41558-021-01033-6 (online),