Policy guidance and pitfalls aligning IPCC scenarios to national land
emissions inventories
- Matthew Gidden
, - Thomas Gasser
, - Giacomo Grassi,
- Niklas Forsell,
- Iris Janssens,
- William F Lamb,
- Jan Minx,
- Zebedee Nicholls
, - Jan Steinhauser
, - Keywan Riahi

Matthew Gidden

Climate Analytics
Corresponding Author:gidden@iiasa.ac.at
Author ProfileThomas Gasser

International Institute for Applied Systems Analysis
Author ProfileNiklas Forsell
International Institute for Applied Systems Analysis
Author ProfileIris Janssens
International Institute for Applied Systems Analysis
Author ProfileWilliam F Lamb
Mercator Research Institute on Global Commons and Climate Change
Author ProfileJan Minx
Mercator Research Institute on Global Commons and Climate Change
Author ProfileZebedee Nicholls

International Institute for Applied Systems Analysis
Author ProfileJan Steinhauser

International Institute for Applied Systems Analysis
Author ProfileKeywan Riahi

International Institute for Applied Systems Analysis
Author ProfileAbstract
Taking stock of global progress towards achieving the Paris Agreement
requires measuring aggregate national action against modelled mitigation
pathways. Because of differences in how land-based carbon removals are
defined, scientific sources report higher global carbon emissions than
national emissions inventories, a gap which will evolve in the future.
We establish a first estimate aligning IPCC-assessed pathways with
inventories using a climate model to explicitly include indirect carbon
removal dynamics on land area reported as managed for by countries.
After alignment, we find that key global mitigation benchmarks can
appear more ambitious when considering this extra land sink, though
changes vary amongst world regions and temperature outcomes. Our results
highlight the need to enhance communication between scientific and
policy communities to enable more robust alignment in the future.