CASE STUDY DETAIL: Pan-tropical (plus China)

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Pan-tropical (plus China)

Project time

January 2013 - January 2014


Carry out a multi-scale pan-tropical modeling of the Non-Renewable Biomass fraction (fNRB) of woodfuels use in order to strengthen GACC action by highlighting priority areas of intervention. The study has a multi-scale geospatial approach : Tier 1 covers tropical countries (plus China), now completed and here profiled, Tier 2 covering one selected country in each region and Tier 3 covering select areas within such countries for in-depth project-level analyses (both in progress).

Institutional settings

The study "Geospatial Analysis and Modeling of Non-Renewable Biomass: WISDOM and beyond", commissioned by the Global Alliance for Clean Cookstoves (GACC) and supported by UN Foundation, is implemented by the Yale School of Forestry and Environmental Studies (FES) in partnership with the Centro de Investigaciones en Geografía Ambiental (CIGA) and the Centro de Investigaciones en Ecosistemas (CIEco) of the National Autonomous University of Mexico (UNAM).


The pan-tropical analysis (Tier 1) has a resolution of 10 arc-second (approx. 300 m) for the Supply Module layers and 30 arc-second (approx. 900 m) for all other phases of analysis. fNRB rates are produced for 1482 administrative units within 90 countries.

Demand features

Rural and urban demand in 2009 was estimated using a combination of national and sub-national country studies supplemented by data from FAO, IEA and UN Energy Statistics and mapped using urban/rural population mapping (FAO and CIESIN).

Supply features

The Supply Module was based on Globcover 2009, Global Ecological Zones (FAO) and Tree Cover data (Hansen et al). For stock and growth a hybrid approach was applied based on: 1) maps of aboveground biomass (AGB), 2) geo-referenced field plots with stock and MAI, and 3) forest inventories from known locations. FAO data was also used for plantation areas and industrial roundwood production. Accessibility was defined using legal (PAs) and physical features (travel time map built ad-hoc).

Integration features

The supply/demand balance was estimated and mapped at pixel level and in a local context of 4.5 km. Commercial balance was mapped considering the resources economically viable.

Woodshed/bio-shed analysis

Woodshed analysis was based on weighted interpolation using Dinamica EGO, combining fuelwood demand from major deficit sites and friction parameters. The probable harvesting zones were defined using transport time thersholds.

Integration with other aspects

WISDOM was further expanded to assess NRB fraction of woodfuels harvesting at sub-national level. Range of fNRB values was estimated, based on assumptions about local forest management, forest productivity, and land cover change (LCC).


Global woodfuel demand in 2009 was ~1.36 Gt. Of this, 22-34% was harvested unsustainably (fNRB), depends on the extent to which LCC by-products are utilized. Figure A3.38 shows fNRB of direct woodfuel harvesting assuming that LCC by-products in accessible areas are utilized. This is the first globally consistent set of fNRB estimates and it is especially relevant for the Global Alliance’s stakeholders because it indicates the NRB that could be reduced by introducing efficient stoves or fuel switching


Article in Nature Climate Change:
Bailis, Robert; Drigo, Rudi; Ghilardi, Adrian; and Masera, Omar. 2015. The carbon footprint of traditional woodfuels. Nature Climate Change. March 2015. doi:10.1038/nclimate2491
Press release by Yale School of Forestry and Environmental Studies
Drigo R., R. Bailis, O. Masera, and A. Ghilardi. Pan-tropical analysis of woodfuel supply, demand and sustainability. Tier I : Final Report. May 2014. Yale-UNAM NRB Project.