Climate Change Mitigation and Agriculture

Eva Wollenberg, Marja-Liisa Tapio-Bistrom, Maryanne Grieg-Gran, Alison Nihart, Eva Wollenberg, Marja-Liisa Tapio-Bistrom, Maryanne Grieg-Gran, Alison Nihart

• Verlag: Routledge
• Jahr: 2013
• ISBN:
  9781136503443
• Auflage: 1
• Thema: Technology & Engineering
• Thema: Sustainable Agriculture

This book reviews the state of agricultural climate change mitigation globally, with a focus on identifying the feasibility, opportunities and challenges for achieving mitigation among smallholder farmers. The purpose is ultimately to accelerate efforts towards mitigating land-based climate change. While much attention has been focused on forestry for its reputed cost-effectiveness, the agricultural sector contributes about ten to twelve per cent of emissions and has a large technical and economic potential for reducing greenhouse gases. The book does not dwell on the science of emissions reduction, as this is well covered elsewhere; rather, it focuses on the design and practical implementation of mitigation activities through changing farming systems.

Climate Change Mitigation and Agriculture includes chapters about experiences in developed countries, such as Canada and Australia, where these efforts also have lessons for mitigation options for smallholders in poorer nations, as well as industrialising countries such as Brazil and China. A wide range of agroecological zones and of aspects or types of farming, including livestock, crops, fish farming, fertilizer use and agroforestry, as well as economics and finance, is included. The volume presents a synthesis of current knowledge and research activities on this emerging subject. Together the chapters capture an exciting period in the development of land-based climate change mitigation as attention is increasingly focused on agriculture's role in contributing to climate change.

Part I

Introduction

1

Climate Change Mitigation and Agriculture

Designing Projects and Policies for Smallholder Farmers

Eva Wollenberg, Marja-Liisa Tapio-Biström Maryanne Grieg-Gran

Introduction

Tackling climate change requires attention to agriculture. Raising crops and livestock directly contributes an estimated 10–12% of anthropogenic greenhouse gas emissions globally¹ (Smith et al. 2008), or about one-third of emissions if indirect impacts on land-use change and land degradation are considered (Smith et al. 2007a: 499). Agricultural emissions are also expected to increase in the next 30 years as population, income, agricultural intensification and diet preferences for meat and dairy increase, particularly in low- and middle-income countries.

In light of these trends and the need to feed a world of an estimated 9 billion people in 2050, some have called for the “redesign of the whole food system” to achieve sustainability and climate change mitigation (Foresight 2011). Fortunately, even modest shifts in agricultural practices can reduce net emissions.² The biophysical potential for mitigation in agriculture is comparable to that of the energy and industrial sectors and exceeds that of the transport sector (Smith et al. 2007a). As agriculture is a major driver of deforestation and other land-use change, measures that halt expansion of agriculture and retain carbon-rich forests or grasslands would reduce future emissions further. Such reductions require, however, meeting the demand for agricultural products from less land.

Agriculture thus holds enormous potential for mitigating climate change. Yet, how to achieve agricultural climate change mitigation in practice still raises major challenges, particularly for resource-poor and smallholder farmers in developing countries. The purpose of this book is to review the state of knowledge of the practice of climate change mitigation in agriculture and provide guidance for its further development.

Chapters from more than 100 authors, involving many of the leading actors in agricultural climate change, examine what we know and what we still need to learn about agricultural mitigation. The authors review technical options, incentives, project design, measurement and monitoring systems, supporting policy measures and impacts. Together they demonstrate the scope for mitigation in different agricultural sectors, major mitigation initiatives and approaches for pursuing mitigation. The chapters indicate the urgency of identifying institutional mechanisms, incentives and policies that work in particular places for particular people. The chapters should provide a foundation for further action by identifying the experiences, methods and principles that can inform the design of agricultural mitigation.

We focus on the estimated 500–800 million resource-poor and smallholder farmers in developing countries for their important role in climate change mitigation in agriculture and the special challenges they face in pursuing their livelihoods and food security. The majority (74%) of agricultural emissions originate in low- and middle-income countries, where smallholders predominate. The emissions in these countries are expected to increase rapidly as a proportion of the global total—especially in Latin America and Africa where expanded fertilizer use, cattle raising and agriculture generally, are expected (Smith et al. 2007a). To have a major impact on global emissions it therefore will be necessary to reach smallholder farmers and not only target developed countries or large farmers and agri-business.

Yet smallholder farmers have particular needs for food and economic security, a low capacity to absorb risk, and poor access to finance and information. Mitigation measures need to give attention to the characteristics of these farmers to be relevant to their needs. Technical options backed by appropriate incentives that achieve mitigation, as well as food security and improved livelihoods will be necessary. Clear benefits for farmers need to be available from mitigation, whether in the form of improved productivity, positive social impacts such as empowerment, or payments. Also, mitigation measures must support farmers’ adaptation to climate change if mitigation is to be achieved in the long term. Linking mitigation to rural development policies will be necessary to coordinate interventions and achieve the large scales necessary for impact on the climate.

Policies and projects therefore need to be designed with the aspirations and constraints of smallholders in mind. Given this goal, the book addresses three challenges. First, how can institutions and incentives best support smallholder farmers to participate in and benefit from agricultural mitigation? Second, what kinds of low-cost, rapid measurement and accounting approaches are needed to assess how smallholders’ practices affect greenhouse gas (GHG) emissions? Third, what are the impacts and trade-offs of mitigation on smallholders’ livelihoods and food security?

Scope

Agriculture refers here to the cultivation of land for crops, the tending of livestock and agroforestry. Mitigation includes direct emissions from agriculture, as well as indirect emissions from land use change.

We intentionally focus on agriculture or the production of food at the farm level, rather than mitigation across the food value chain or food system. Life cycle analysis shows that for most food products, emissions from production at the field level greatly exceed those generated from processing, transportation and distribution or storage (Garnett 2008, Weber and Matthews 2008), especially in developing countries where the majority of production is consumed domestically.³ We do not examine energy or biofuel aspects of mitigation, as these deserve extensive treatment that is beyond the scope of the current volume.

Although the book is focused on developing countries, we have included examples from developed countries where they provided lessons or models of potential interest to smallholder-based mitigation.

We refer henceforth to agricultural mitigation or mitigation for brevity. We use the term smallholder to describe smallholder farmers in developing countries unless noted otherwise.

Organization of the Book

The book is organized in four parts. Part I (Introduction) establishes the context for agricultural mitigation. The authors review available technical options and current projects, and discuss where opportunities exist to jointly pursue food security, livelihoods and adaptation to climate change.

Part II then explores the institutional arrangements and incentives to support mitigation systems. As we discuss below, the design of institutions and incentives is critical to make mitigation economically viable for farmers and encourage shifts in farming practices. This section includes chapters on smallholders’ access to the carbon market and experiences to date. Shames et al. proposes design principles for improving smallholders’ participation and benefits. Haywood et al. examine the role of certification as a driver for mitigation and identifies emerging best practices. The policies supporting agricultural mitigation and the lessons from experience in developing Reduced Emissions from Deforestation and Forest Degradation (REDD) are covered by Negra and Wollenberg.

The section also covers the financial arrangements and markets that support mitigation. East Africa is a leader in agricultural carbon market projects, hence the book draws heavily from examples in this region. The Kenya Agricultural Carbon Project (KACP), in particular, has pioneered the sale of carbon credits from soil management in smallholder farming and is reviewed in the chapters by Lager and Nyaberg, Shames et al., and Lee and Newman.

Due to the importance of land-use change and the conversion of forests for agriculture, Part II includes several chapters about institutional arrangements for managing across agriculture and forests. The chapters provide examples of landscape approaches from Brazil and Australia that capture land-use change and the interactions between agriculture and forests. The section concludes with the experiences of a network in China seeking to promote sustainable agriculture that also reduces impacts on the climate.

In Part III we highlight key developments and issues concerning the methods for quantifying and accounting for greenhouse gas emissions. The chapter by Hillier et al. introduces the Cool Farm Tool, an emissions calculator designed for farmers to help them understand how and where to best reduce emissions. Other chapters review methods for rapid and low-cost measurement, including soil carbon measurement, modeling and activity-based monitoring. ‘Emissions intensity’, or output-based measures for carbon crediting, are discussed in the chapter by Baker and Murray as a means for better capturing mitigation gains relative to agricultural productivity. The section concludes with an overview by Swickard and Nihart of the Verified Carbon Standard (VCS) as the current predominant platform for agricultural carbon credits, and the lessons VCS has learned.

Part IV gives examples of mitigation in different agricultural sectors. The chapters in this section reflect the state-of-the-art of knowledge in each sector and identify gaps in knowledge. They give special attention to trade-offs among outcomes.

In the remainder of this chapter we synthesize findings from the chapters related to: (1) technical options for mitigation; (2) institutional and economic options; and (3) measurement and accountability. We also introduce basic concepts and discuss the status of projects, policies and major initiatives to show the state of play for agricultural mitigation. We conclude with principles and next steps for the design of agricultural mitigation policies and projects for smallholders.

Technical Options

The potential for agricultural mitigation has been well summarized by the Intergovernmental Panel on Climate Change (Smith et al. 2007a). All three major greenhouse gases—carbon dioxide (CO₂), nitrous oxide (N₂O) and methane (CH₄)—play a role in agriculture. Nitrous oxide and methane contribute nearly all of agriculture’s direct emissions (Figure 1.1 and Table 1.1). Indirectly, land-use conversion due to agriculture is a major source of carbon emissions. Eighty percent of direct and indirect emissions from agriculture are estimated to be related to livestock (Neely and Leeuw, this volume).

Figure 1.1 Global contribution of agriculture to greenhouse gas emissions (source:Bellarby et al. 2008: 5).

Table 1.1 Sources of direct and indirect agriculture greenhouse gases

Sources of agriculture GHG	Million tonnes CO2e
Nitrous oxide from soils	2,128
Methane from cattle enteric fermentation	1,792
Biomass burning	672
Rice production	616
Manure	413
Fertilizer production	616
Irrigation	369
Farm machinery (seeding, tilling, spraying, harvest)	158
Pesticide production	72
Land conversion to agriculture	5,900

Source: Bellarby (2008: 6)

From a technical standpoint, agricultural mitigation is feasible and significant. Three options exist for managing GHGs: (1) reduce current methane and nitrous oxide emissions; (2) increase removals of GHGs from the atmosphere, mostly through increased carbon sequestration; or (3) avoid creating new emissions, e.g., by protecting the storage of carbon in existing biomass or soil carbon, or by substituting renewable energy sources for petroleum energy. The sum of emissions and removals is referred to as net emissions. For agricultural mitigation to have a significant impact on GHGs, large areas need to be covered, as the net emissions reduced per unit of land area is relatively small. Other approaches to managing climate change, such as changing aerosols or the albedo of vegetative cover warrant further exploration (Ridgewell et al. 2009), but are beyond the scope of this book.

Reducing CO₂ emissions from the soil has the largest biophysical potential for mitigation among options in annual crop systems (i.e., not considering agroforestry or other perennial agricultural systems). Reducing net CO₂ emissions from cultivated organic soils or sequestering carbon in mineral soils is estimated to provide about 89% of the GHG reductions possible by 2030 (Smith et al. 2007a).⁴ This is equivalent to about 4,895–5,380 Mt CO₂e/yr (Smith et al. 2008).

Maintaining and increasing existing stocks of sequestered carbon in the soil and perennial vegetation are therefore a high priority. The potential impact of carbon sequestration is almost 10 times more than the potential from reducing both N₂O and CH₄ emissions, based on IPCC figures (Smith et al. 2007a). Carbon sequestration becomes limited over time, however, as soils reach carbon saturation points. Preventing loss of any newly sequestered carbon from fire, tillage and land conversion also will be necessary⁵(Neely and de Leeuw, this volume). Biochar may prove to be a more stable carbon sink that is less vulnerable to these perturbations and could be an alternative to burning plant material to maintain soil fertility (L...