Land Use in the 21st Century: Contributing to the Global Public Good

• Published date: 01 May 2017
• Date: 01 May 2017
• DOI: http://doi.org/10.1111/rode.12295

Land Use in the 21st Century: Contributing to the

Global Public Good

Thomas W. Hertel*

Abstract

This paper focuses on the evolution of global public goods related to the world’s land resources over the

course of the 21st century, their potential impacts on the world’s poorest households, as well as prospects

for policy interventions aimed at enhancing these outcomes. It begins with global scale projections to

2100 of land use and associated goods and services, including food, fuel, timber, greenhouse gas

emissions, carbon sequestration and biodiversity. This is followed by in-depth discussion of each of these

services and the challenges of providing these public goods in suff‌icient quantities to advance societal

welfare—especially that of the world’s poorest households. The paper concludes with a discussion of

policies aimed at promoting the provision of land-based public goods and how they could be altered to

be more pro-poor. Within this context, the paper argues that access to geospatial analysis tools and

information on climate, land use and tenure, poverty and environmental indicators will become

increasingly valuable to both public and private decision makers.

1. Introduction and Historical Perspective

Land is arguably the world’s most important natural resource. It provides a host of

public and private goods and humankind has played a large role in shaping its

evolution over the millennia. Ramankutty et al. (2006) point out that people have

been involved in inducing land cover change since the beginning of human history.

Today, about one-third of the world’s land cover is devoted to agriculture, one-

third to forests and one-f‌ifth to savannas, grasslands and shrublands (Ramankutty,

2010). While the global area devoted to crops has changed only modestly in the

past 50 years, the distribution of these croplands has changed much more

dramatically (Ramankutty et al., 2008). Indeed, global land cover change

accelerated to unprecedented levels during this time period (Lepers et al., 2005),

and this, in turn, has had consequences for the associated ecosystem services

available at local, regional and global scales. Much of the cropland expansion

during the past half century has been in the tropics (Ramankutty et al., 2002).

There is evidence that the cropland expansion in the tropics has come at the

expense of closed tropical forests (Gibbs et al., 2010). These areas are particularly

rich in biodiversity as well as carbon (West et al., 2010).

The question of global adequacy of the world’s land resources to meet continuing

growth in demand for food, f‌iber, fuel and other ecosystem services has important

implications for the world’s poor. The bulk of the world’s poor reside in rural areas,

and many of these households still “live off the land” in one way or another. Many

are smallholder farmers, others are employed in agriculture or forestry activities

*Hertel (Corresponding author): Department of Agricultural Economics, Purdue University, West

Lafayette, IN, 47907-1145, USA. E-mail: hertel@purdue.edu.

The copyright line for this article was changed on 09 February 2017 after original online publication.

Review of Development Economics, 21(2), 213–236, 2017

DOI:10.1111/rode.12295

©2016 UNU-WIDER. Review of Development Economics Published by John Wiley & Sons Ltd.

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike License, which permits use

and distribution in any medium, provided the original work is properly cited, the use is non-commercial and the content is offered under

identical terms.

and others still rely on hunting and gathering for a signif‌icant portion of their

income and/or sustenance (Cavendish, 2000). Efforts to increase the provision of

land-based public goods will affect these households directly, when they are either

displaced (e.g. by a nature preserve) or when they are paid for providing these

services themselves (e.g. for carbon sequestration or forest conservation). There are

also important indirect effects that arise when the overall availability of land is

altered, thereby affecting food prices and rural employment opportunities.

This paper begins with an overview of how global land use and the associated

public and private goods and services are likely to change over the course of the

21st century. It then offers an in-depth analysis of key, land-based public goods

(Table 1), including carbon sequestration, bioenergy, biodiversity, and institutions

to facilitate climate adaptation, including information and analysis tools to adapt to

the changing environment. The paper focuses on areas where under-provision of

these public goods is likely and, in such cases, it discusses the potential for public

policies, research and development assistance to enhance their provision.

2. The Evolving Global Supply and Demand for Land-based Goods and

Services in the Twenty-f‌irst Century

Before examining the specif‌ic public goods associated with global land use, it is

useful to step back and evaluate how we expect global land use to change over the

coming century. What are the fundamental drivers behind global land use and the

associated goods and services? Towards this end, we draw on projections for global

land use change and land-based greenhouse gas (GHG) emissionsover the 21st

century developed by Steinbuks and Hertel (2016) using the FABLE (Forestry

Agriculture Biofuels Landuse and Environment) model. FABLE is a discrete,

dynamic, partial equilibrium optimization model that runs at global scale and

characterizes long run competition for land between food, biofuel, forest products,

carbon sequestration and other land-based ecosystem services. FABLE allocates long

run global land uses in order to maximize the discounted social value obtained from

these land-based goods and services, subject to available technology and biophysical

constraints, including the global land endowment and explicit growth functions for

food crops, bioenergy crops and forests, by vintage. FABLE is “forward-looking,”

which means that optimal land use change today is inf‌luenced by expectations of

developments in the future, including energy prices, population and income growth,

new technologies and government policies. In the baseline scenario, real fossil fuel

costs rise at an annual rate of 3% (Energy Information Agency, 2010), population

growth slows, plateauing at 10 billion people in 2100 (Bloom, 2011), global per capita

income grows at about 2%/year and, in the absence of climate mitigation policies,

GHG accumulation in the atmosphere causes global temperatures over agricultural

areas to rise at an average rate of 0.3 degC/decade (Intergovernmental Panel on

Climate Change (IPCC), 2007). (Given their inherent uncertainty, alternative paths

for these underlying drivers of land use change will be explored later on.)

Figure 1(a) reports the evolving allocation of global agricultural and forest land

use over the 21st century, according to the FABLE baseline. Area devoted to food

production continues to rise to 2040, as demand growth, driven by rising population

and dietary upgrading, outpaces productivity growth. However, by 2040, the

combination of slowing population growth, improved productivity and competition

from second generation biofuels, results in cropland devoted to food production

declining after 2040, ending the century 12% below current levels. In contrast to

214 Thomas W. Hertel

©2016 UNU-WIDER. Review of Development Economics Published by John Wiley & Sons Ltd.