Food Nitrogen Footprint Increased by 35% on the Third Pole During 1998-2018

Area of Science:

• Environmental Science
• Agricultural Science
• Ecology

Background:

• Nitrogen (N) footprint serves as a key indicator of environmental damage from N.
• Understanding N footprint distribution, sources, and drivers is crucial for mitigating impacts and promoting sustainable N management.

Purpose of the Study:

• To construct a city-scale food N footprint (FNF) framework for the Qinghai-Tibet Plateau (QTP).
• To quantitatively analyze FNF during food production and consumption on the QTP from 1998 to 2018.
• To investigate the driving forces and decoupling trends of the FNF.

Main Methods:

• Nitrogen mass balance approach to construct the FNF framework.
• Logarithmic mean Divisa index decomposition method to analyze driving forces.
• Analysis of FNF changes and spatial distribution from 1998 to 2018.

Main Results:

• The per capita FNF increased from 24.92 kg N cap⁻¹ to 27.70 kg N cap⁻¹ between 1998 and 2018.
• Total FNF increased by 35.11% over the study period, with uneven spatial distribution.
• N losses from crop and animal production constituted 86% of the FNF; economic development and urbanization were primary drivers.

Conclusions:

• Economic development and urbanization significantly increased the FNF, while N consumption intensity had an inhibitory effect.
• A gradual decoupling of FNF from economic development was observed in the eastern QTP.
• Promoting N recycling within food production and consumption systems is essential for reconciling socioeconomic drivers and FNF.