Conserving the Cerrado and Amazon biomes of Brazil protects the soy economy from damaging warming

Rafaela Flach,Aline C. Soterroni,Fernando M. Ramos,Avery S. Cohn,Gabriel Abrahão,Hugo Valin,Marluce Scarabello,Michael Obersteiner,Benjamin Bryant

doi:10.1016/j.worlddev.2021.105582

Abstract

In tropical regions, widespread loss of native forest and savanna vegetation is increasing extreme heat, particularly in agricultural regions. Using the case of rising extreme heat from lost forest and savanna vegetation in Brazilian Amazon and Cerrado regions, we modeled losses to soy production, the region’s principal economic activity. We assessed two types of extreme-heat regulation values: the value of avoided extreme-heat exposure of soy from the conservation of neighboring ecosystems and the value of lost revenue due to increased extreme heat exposure from increased ecosystem conversion. Our modeling combines empirical estimates of (1) the influence of ecosystem conversion on extreme heat over neighboring cropland, (2) the impacts of extreme heat on agricultural yields, and (3) native vegetation area, agricultural area, and crop prices. We examine lost soy value from land conversion over the period 1985 to 2012, potential losses from further conversion under plausible land and climate change scenarios (2020–2050), and the future value of conservation of the region’s remaining ecosystem area near soy. Soy revenue lost due to extreme heat from native vegetation loss (1985–2012) totaled 99 (2005USD) ha−1 for 2012-2013 growing season. By 2050, agricultural growth, ecosystem conversion, and climate change could boost extreme-heat regulation values by 25% to 95%. Future values were strongly sensitive to changes in agricultural density, rates of native vegetation loss, and climate. Extreme-heat regulation values were largest in the Cerrado biome and the southeastern Amazon. Relative to land values, the value of extreme heat regulation was largest relative to the carbon value of biomass in the Cerrado. By regulating the exposure of agriculture to extreme heat, ecosystem conservation can create considerable value for the soy sector.

Highlights

In recent decades, Brazil has seen tremendous agricultural growth, fueled in part by its emergence as a major agricultural exporter (Zalles et al, 2019)
This paper explores whether the economic risks to agriculture posed by climate change and exacerbated by ecosystem conversion might meaningfully inform the value of conservation, including the private returns to conservation
Changes in extreme heat related to ecosystem conversion Extreme heat exposure was derived from estimating the extreme degree day (EDD) parameter

Summary

Introduction

Brazil has seen tremendous agricultural growth, fueled in part by its emergence as a major agricultural exporter (Zalles et al, 2019). The growth of the soy sector happened both by intensification of production (mean yield growing from 1.7 to 3.2 tons per hectare between 1990 and 2019) and area expansion (from 11.5 to 35.8 million ha between 1990 and 2019) (IBGE, 2020). This growth occurred especially in new agricultural regions to the north and west of established agricultural poles, in the Amazon and Cerrado biomes, respectively (Dias et al, 2016).

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