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

In Nature Climate Change
Volume (Issue): 11
Peer-reviewed Article

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.

Author:
Giacomo
Grassi
Elke
Stehfest
Joeri
Rogelj
Detlef
van Vuuren
Alessandro
Cescatti
Jo
House
Gert-Jan
Nabuurs
Simone
Rossi
Ramdane
Alkama
Raúl
Abad Viñas
Katherine
Calvin
Guido
Ceccherini
Sandro
Federici
Shinichiro
Fujimori
Mykola
Gusti
Tomoko
Hasegawa
Petr
Havlik
Florian
Humpenöder
Anu
Korosuo
Lucia
Perugini
Francesco N.
Tubiello
Alexander
Popp
Date: