A multi-data assessment of land use and land cover emissions from Brazil during 2000–2019

Thais M Rosan,Andrew Wiltshire,Julia Pongratz,Pierre Friedlingstein,Raphael Ganzenmüller,Lina M Mercado,Francesco N Tubiello,Michael O’Sullivan,Viola Heinrich,Ana Bastos,Celso Von Randow,Kees Klein Goldewijk,Stephen Sitch,Luiz E O C Aragao

doi:10.1088/1748-9326/ac08c3

Abstract

Brazil is currently the largest contributor of land use and land cover change (LULCC) carbon dioxide net emissions worldwide, representing 17%–29% of the global total. There is, however, a lack of agreement among different methodologies on the magnitude and trends in LULCC emissions and their geographic distribution. Here we perform an evaluation of LULCC datasets for Brazil, including those used in the annual global carbon budget (GCB), and national Brazilian assessments over the period 2000–2018. Results show that the latest global HYDE 3.3 LULCC dataset, based on new FAO inventory estimates and multi-annual ESA CCI satellite-based land cover maps, can represent the observed spatial variation in LULCC over the last decades, representing an improvement on the HYDE 3.2 data previously used in GCB. However, the magnitude of LULCC assessed with HYDE 3.3 is lower than estimates based on MapBiomas. We use HYDE 3.3 and MapBiomas as input to a global bookkeeping model (bookkeeping of land use emission, BLUE) and a process-based Dynamic Global Vegetation Model (JULES-ES) to determine Brazil’s LULCC emissions over the period 2000–2019. Results show mean annual LULCC emissions of 0.1–0.4 PgC yr−1, compared with 0.1–0.24 PgC yr−1 reported by the Greenhouse Gas Emissions Estimation System of land use changes and forest sector (SEEG/LULUCF) and by FAO in its latest assessment of deforestation emissions in Brazil. Both JULES-ES and BLUE now simulate a slowdown in emissions after 2004 (−0.006 and −0.004 PgC yr−2 with HYDE 3.3, −0.014 and −0.016 PgC yr−2 with MapBiomas, respectively), in agreement with the Brazilian INPE-EM, global Houghton and Nassikas book-keeping models, FAO and as reported in the 4th national greenhouse gas inventories. The inclusion of Earth observation data has improved spatial representation of LULCC in HYDE and thus model capability to simulate Brazil’s LULCC emissions. This will likely contribute to reduce uncertainty in global LULCC emissions, and thus better constrains GCB assessments.

Highlights

Brazilian ecosystems and especially forests play a fundamental role in regional and global carbon stocks and natural land C sinks
Land use and land cover changes in Brazil We find temporal agreement between both remote sensing-based products (ESA CCI and MapBiomas) and HYDE 3.3 at country level
The three datasets agreed on the peak land use and land cover change (LULCC) in Brazil between 2003 and 2005 with a negative trend thereafter opposite to the positive trend shown by HYDE 3.2 (figure 1(a))

Summary

Introduction

Brazilian ecosystems and especially forests play a fundamental role in regional and global carbon stocks and natural land C sinks. The Amazon forest is estimated to contain around 229–280 PgC in living biomass and soils (Malhi et al 2006, Gloor et al 2012), representing ∼10% of global land C stocks (Ciais et al 2013), and approximately 60% of its area is in Brazil. Despite a significant slowdown in deforestation in Brazil after a peak in 2004, mainly due to policy introduced to curb deforestation (Arima et al 2014, Godar et al 2014, West and Fearnside 2021), Brazil is still contributing with between 17% and 29% of global LULCC emissions (ELUC) (Friedlingstein et al 2019). Divergent ELUC estimates for Brazil in the global carbon cycle budget have contributed to a large fraction of the corresponding overall global uncertainty (Bastos et al 2020)

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