Macroeconomic Impacts of Climate Change Driven by Changes in Crop Yields

Shinichiro Fujimori,Kiyoshi Takahashi,Yasuaki Hijioka,Toshichika Iizumi,Tomoko Hasegawa,Jun’Ya Takakura

doi:10.3390/su10103673

Abstract

Changes in agricultural yields due to climate change will affect land use, agricultural production volume, and food prices as well as macroeconomic indicators, such as GDP, which is important as it enables one to compare climate change impacts across multiple sectors. This study considered five key uncertainty factors and estimated macroeconomic impacts due to crop yield changes using a novel integrated assessment framework. The five factors are (1) land-use change (or yield aggregation method based on spatially explicit information), (2) the amplitude of the CO2 fertilization effect, (3) the use of different climate models, (4) socioeconomic assumptions and (5) the level of mitigation stringency. We found that their global impacts on the macroeconomic indicator value were 0.02–0.06% of GDP in 2100. However, the impacts on the agricultural sector varied greatly by socioeconomic assumption. The relative contributions of these factors to the total uncertainty in the projected macroeconomic indicator value were greater in a pessimistic world scenario characterized by a large population size, low income, and low yield development than in an optimistic scenario characterized by a small population size, high income, and high yield development (0.00%).

Highlights

The economic impact of climate change on key economic sectors has been studied for a long time
computable general equilibrium (CGE) models are suitable for the analysis of such influences, and they have been used in many of the studies mentioned above compared to partial equilibrium models
Here we focused on macroeconomic implications in order to obtain climate change impact information that is comparable across sectors, we should note that it does not mean agricultural climate change is less important despite small macroeconomic changes

Summary

Introduction

The economic impact of climate change on key economic sectors has been studied for a long time. Et al [6] analyzed the economic impacts of reduction in agriculture production using a partial equilibrium model, and estimated which regions of the world would be winners or losers under climate change. Et al [10] investigated the economic effects of climate change in Europe, and found that a macroeconomic loss of about 0.3% would occur in most global warming scenarios when using a CGE model. The order of magnitude of the projected global agricultural economic losses due to climate change is small (about 0–1% of GDP). It is reasonable to use food prices and population at risk of hunger as indicators rather than GDP change when assessing climate change impacts on the agricultural sector

Objectives

Methods

Results

Conclusion