Details

Autor(en) / Beteiligte

• Wang, Qihui
• Zhou, Feng
• Shang, Ziyin
• Ciais, Philippe
• Winiwarter, Wilfried
• Jackson, Robert B
• Tubiello, Francesco N
• Janssens-Maenhout, Greet
• Tian, Hanqin
• Cui, Xiaoqing
• Canadell, Josep G
• Piao, Shilong
• Tao, Shu

Titel

Data-driven estimates of global nitrous oxide emissions from croplands

Ist Teil von

• National science review, 2020-02, Vol.7 (2), p.441-452

Ort / Verlag

China: Oxford University Press

Erscheinungsjahr

2020

Link zum Volltext

Quelle

EZB*

Beschreibungen/Notizen

• Abstract Croplands are the single largest anthropogenic source of nitrous oxide (N2O) globally, yet their estimates remain difficult to verify when using Tier 1 and 3 methods of the Intergovernmental Panel on Climate Change (IPCC). Here, we re-evaluate global cropland-N2O emissions in 1961–2014, using N-rate-dependent emission factors (EFs) upscaled from 1206 field observations in 180 global distributed sites and high-resolution N inputs disaggregated from sub-national surveys covering 15593 administrative units. Our results confirm IPCC Tier 1 default EFs for upland crops in 1990–2014, but give a ∼15% lower EF in 1961–1989 and a ∼67% larger EF for paddy rice over the full period. Associated emissions (0.82 ± 0.34 Tg N yr–1) are probably one-quarter lower than IPCC Tier 1 global inventories but close to Tier 3 estimates. The use of survey-based gridded N-input data contributes 58% of this emission reduction, the rest being explained by the use of observation-based non-linear EFs. We conclude that upscaling N2O emissions from site-level observations to global croplands provides a new benchmark for constraining IPCC Tier 1 and 3 methods. The detailed spatial distribution of emission data is expected to inform advancement towards more realistic and effective mitigation pathways.