Alcoa Chair in Sustainable Water Management

Richard J. Harper

Carbon sequestration: conflicts and benefits

Overview

Land based carbon mitigation can contribute to restoring the carbon balance

This includes sequestration of carbon in plants and soils, replacement via bioenergy

Co-benefits - Large scale carbon investment could have a significant impact on land degradation, water, production, biodiversity

Competition – Food vs fuel, trees vs water

Broader context - multiple values from land (food, water, fibre, biodiversity, habitation)

Land-use emissions

Activity 2006emission(%)*

Aust.Kyoto

Accts

Annex A Agriculture emissions (methane, nitrous oxide)

16 yes

Art. 3.3 Afforestation/reforestation -4 yes

Deforestation 11 yes

Art. 3.4: Cropland management 0 no

Grazing land management

Revegetation

Forest management

*Source: Australian National Greenhouse Gas Inventory (2006)

Bioenergy

Different approach: replacement of fossil fuels

Fermentation• Ethanol from grain

Direct combustion• Forestry wastes• Purpose grown energy crops

Second generation – transport fuels• “lignocellulosics” and other

processes

Article 3.3: Types of reforestation

Afforestation/reforestation: discussion points

Reasonable certainty - Growth rates known for many species and situations

Timber and fibre production; replacement of energy intensive products (e.g. steel)

Environmental co-benefits (water quality, biodiversity); funding mechanism for land-conservation at scale, translocation of natural species with climate change

Competition between agricultural land use and carbon mitigation (“food vs fuel”)

Competition for water

Deforestation: discussion points

Major source of global emissions

Protection of forests will provide biodiversity, water quality benefits

Conversion of land to agriculture – where is future food production going to come from?

Economic development and equity: how can forests be protected without penalizing local communities?

Article 3.4: additional activities

Cropland management Grazing land management

Revegetation Forest management

Article 3.4 additional activities

Based on small increments of carbon over large areas

Often uncertainty in estimates; difficulties in measurement

Risk of achieving net emissions, rather than net sequestration e.g. drought, erosion, fire

Co-benefits (soil C, production, rangeland restoration etc)

Source: CPRS Green Paper, p. 121 (2008)

Conclusions…

There are a range of carbon mitigation options within the land-use sector

Carbon investment will provide a new source of capital; potential for large-scale change

Range of benefits and disbenefits from large-scale land-use change

Consider all costs and benefits through several lenses – economic, energy, carbon, food and water security, biodiversity and social

Challenge is to design new land-use systems that capture carbon investment and optimise these multiple factors