Carbon emissions from global impervious surface expansion between 1985 and 2020

Area of Science:

• Environmental Science
• Ecology
• Climate Change Research

Background:

• Impervious surface expansion (ISE) covers natural land with artificial materials due to urbanization.
• Extensive ISE leads to significant losses in terrestrial ecosystem carbon pools.
• Global assessments of ISE's carbon impact are limited by data availability and uncertainties.

Purpose of the Study:

• To quantify carbon emissions from global ISE between 1985 and 2020.
• To address data gaps and uncertainties in assessing ISE's impact on carbon pools.
• To provide a comprehensive global assessment following IPCC guidelines.

Main Methods:

• Divided global land into 87 fine geographical zones.
• Integrated multiple data products: impervious surface data, land cover dynamics, biomass, and topsoil organic carbon (TSOC).
• Utilized a lookup table (LUT) for biomass and TSOC density and applied IPCC methods for carbon emission estimation.

Main Results:

• Global ISE covered 58.12 million hectares, with 67.30% from cropland encroachment.
• Cumulative carbon emissions reached 1.14 ± 0.38 Petagrams of Carbon (PgC) over 35 years.
• Topsoil organic carbon accounted for 54.55% and biomass carbon for 45.45% of the emissions.

Conclusions:

• Global ISE represents a substantial source of committed carbon emissions.
• Understanding ISE's carbon footprint is crucial for climate change mitigation and land management.
• Future research should focus on refining data and improving models for accurate carbon accounting.