Details

Autor(en) / Beteiligte

• Gidden, Matthew J
• Gasser, Thomas
• Grassi, Giacomo
• Forsell, Nicklas
• Janssens, Iris
• Lamb, William F
• Minx, Jan
• Nicholls, Zebedee
• Steinhauser, Jan
• Riahi, Keywan

Titel

Aligning climate scenarios to emissions inventories shifts global benchmarks

Ist Teil von

• Nature (London), 2023-12, Vol.624 (7990), p.102-108

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2023

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Taking stock of global progress towards achieving the Paris Agreement requires consistently measuring aggregate national actions and pledges against modelled mitigation pathways . However, national greenhouse gas inventories (NGHGIs) and scientific assessments of anthropogenic emissions follow different accounting conventions for land-based carbon fluxes resulting in a large difference in the present emission estimates , a gap that will evolve over time. Using state-of-the-art methodologies and a land carbon-cycle emulator , we align the Intergovernmental Panel on Climate Change (IPCC)-assessed mitigation pathways with the NGHGIs to make a comparison. We find that the key global mitigation benchmarks become harder to achieve when calculated using the NGHGI conventions, requiring both earlier net-zero CO timing and lower cumulative emissions. Furthermore, weakening natural carbon removal processes such as carbon fertilization can mask anthropogenic land-based removal efforts, with the result that land-based carbon fluxes in NGHGIs may ultimately become sources of emissions by 2100. Our results are important for the Global Stocktake , suggesting that nations will need to increase the collective ambition of their climate targets to remain consistent with the global temperature goals.