Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Reducing greenhouse gas emissions from the terrestrial biosphere

Landcare Research is at the forefront of efforts to understand the impacts of, and achieve reductions in, greenhouse gas emissions, as this 2007 case study for the Crown Company Monitoring Advisory Unit (CCMAU) explains.

Rata forest. Image – John Hunt.

Rata forest. Image – John Hunt.

New Zealand (NZ) must reduce or offset net greenhouse gas emissions to meet its targets under the Kyoto Protocol. By 2012, the most likely cost of offsetting emissions in excess of 1990 levels has been estimated at $680m, but could be as high as $1,900m depending on the area of forest sinks eligible to earn Kyoto-compliant credits and the extent to which deforestation occurs (Ministry for the Environment (MfE) 2007).

Landcare Research has contributed substantially to NZ's efforts to quantify and, where possible, reduce these liabilities. This has been achieved by improving the certainty and international credibility of liabilities estimates through improved inventory methodology, and by providing more accurate emissions factors and evidence to maximise NZ's carbon sink credits. The net benefit to NZ of these initiatives could be as much as $500m during the first commitment period (CP1) of the Kyoto Protocol.

User benefits and national impacts

Our research is improving understanding of the processes that control greenhouse gas emissions (by sources) and removals (by sinks) from NZ's managed and unmanaged land-based activities. This helps to quantify and minimise the economic, social and environmental impacts of climate change; to maximise potential benefits; and to strengthen NZ's ability to meet its international reporting obligations.

Our results enable government agencies to develop more robust policy to reduce net greenhouse gas emissions and deliver improved defensible national greenhouse gas inventories. For example, our data on carbon sequestration rates in reverting indigenous shrublands, and on areas available for reversion (Trotter et al. 2005), were provided to MAF to support the establishment of the Permanent Forest Sinks Initiative (PFSI) - and will also support estimates for the Emissions Trading Scheme.

Subsequent work for MAF and the Department of Conservation (DOC) developed options for indigenous and exotic afforestation of public lands, with predictions of carbon accumulation rates likely to be achieved under a national reforestation programme (Sutherland et al. 2006).

Our knowledge of occurrence of indigenous shrubland, and rates of change in area over time, provided critical information to support claiming the maximum area of post-1990 forested land area eligible for carbon credits under the Kyoto Protocol.

By combining knowledge of regeneration potential and processes with development and validation of a novel new method to analyse current and historical landcover datasets of shrubland and forest occurrence (Barringer et al. in prep.), we provided quantitative evidence that confirmed the eligibility of about half our post-1990 exotic forest sinks, thus ensuring availability of these credits to offset more than $500m of greenhouse gas liabilities during CP1 of the Kyoto Protocol.

We have also designed for MfE, and now lead key components of, the land use, land-use change and forestry (LULUCF) mapping programme that underpins NZ's ability to claim all forest carbon credits used to offset emissions during CP1.

A case study - developing an internationally credible inventory

New Zealand's carbon credits and international credibility come in large part from accurate figures for change in forest area since 1990. Estimation is a difficult task, as decadal rates of change in land use are small - less than 2% of NZ's land area. Error using traditional mapping techniques is more than that for even a single date of mapping, let alone for the two dates of mapping required to detect change. Ordinary mapping approaches are thus neither appropriate nor accurate enough for reporting under the Kyoto Protocol. However, with our in-depth knowledge of inventory and mapping methodologies, and our international experience on inventory design and reporting, we have designed for MfE a combined system of mapping and statistical sampling that offers the advantages of producing maps for all-of-government applications, while also delivering the accuracy needed for Kyoto reporting. The system we proposed was trialled in an internationally contested process, and found to be not only the most cost-effective but also to have substantially better accuracy than other alternatives. Landcare Research, under contract to MfE, have now implemented the more technically demanding components of this mapping system. Data from the system will critically underpin NZ's claim to more than $1 billion of forest carbon credits during CP1.

Our research has also increased awareness by landowners and stakeholders of the economic impacts of climate change, and of future land-use opportunities. Our work is of particular interest to rural communities and owners of marginal pastoral lands, including the significant areas owned by Māori. Converting this land to ‘carbon farming' provides sustainable land use opportunities that also reduce both greenhouse gas emissions and the vulnerabilities of landscapes and downstream infrastructure.

We also develop tools to help landowners evaluate and prioritise land-based options for mitigating and adapting to climate change. Our carbon calculator (freely available on our website) enables landowners to simply compare returns from carbon farming based on indigenous shrubland and forest, under a range of user-adjustable price scenarios, with traditional sheep/beef and forestry operations.

The carbon sequestration rates that underpin the calculator have been used extensively over the last 3 years by Ngāti Porou Forestry to help plan future forestry investment. Collaborative research with Motu Economic and Public Policy Research Trust and Māori landowners contributed significantly to the signing in 2007 of a carbon farming agreement with Māori landowners in Rangitukia, to establish a 10 000-ha forest carbon sink, and reducing New Zealand's annual greenhouse gas liability by up to $600,000.

Involvement of our staff in international reviews and working groups has increased NZ's understanding of, and international influence on, the technical requirements for greenhouse gas accounting and reporting.

This has helped identify areas for improvement in NZ's emissions inventory. For example, our research on indirect nitrous oxide emissions (co-funded by MAF; Clough et al. 2007) provided the basis for reducing the indirect N2O emissions factor from 0.025 to 0.0075 kg N2O-N emitted to the atmosphere per kilogram of N leached from agricultural soils. This change, adopted by MfE in its inventory methodology in April 2007, will reduce the government´s Kyoto Protocol liability by about $18m over CP1.

Our in-depth knowledge of inventory methodology coupled with our expertise in soil carbon sequestration processes has also allowed us to identify an opportunity to save NZ more than $30m in CP1 by improving the existing soil carbon inventory methodology.

End-user links

The needs of our key end-users (principally MfE and MAF) determine many of our research priorities, and we interact with these agencies in a number of ways. We undertake, on average, seven contracts per year for MAF and MfE, applying our data and knowledge to address Government operational and policy issues.

Our experience and knowledge of processes and inventory of terrestrial greenhouse gas emissions and removals is widely sought by policy agencies. Our staff have provided a broad range of expert advice on the implications for NZ of the international accounting rules under the Kyoto Protocol and the United Nations Framework Convention on Climate Change (UNFCCC), as members of in-country review teams for accounting practices, under processes run by the two ministries (MfE and MAF).

Staff have also facilitated pan-departmental workshops at MfE's request to help develop all-of-government understanding and responses to issues raised by NZ's adoption of the Kyoto Protocol. At the request of MfE and MAF, staff have also presented NZ's approach to accounting under the Kyoto Protocol at international fora.

We hold and participate in numerous workshops with local government agencies to enhance awareness of the range and effectiveness of different responses to climate change, and of the economic impacts on land use of potential climate-change-policies.

We have well-established and extensive networks with a wide range of Māori groups, from central government to local hapū, and work with them to realise opportunities consistent with their economic, environmental, social and cultural goals, including developing options for ‘carbon farming' and biofuel production. Our networks give Māori access to the latest science knowledge on climate change issues, and we regularly enhance this knowledge by participation in hui.

Publication of over 170 scientific papers in peer-reviewed scientific journals since 2000 - an average of approximately 25 per year - provides a strong statement on the quality of the research that underpins our initiatives with central and regional government, landowners, and other stakeholders.

Funding and support

Current research is built on an extensive range of process-based research on NZ's major greenhouse gases completed by Landcare Research over the past 15 years. It is also integrated with research programmes on sustainable land use and environmental monitoring. The current programme has received an average of $2.5m per year from FRST since 2000, and supports approximately 13 full-time equivalents (FTEs) annually in research and technical staff.

Sources of information used, and assumptions made

All estimates are based on a market value of CO2 of NZ$15 per tonne, which is likely to prove a rather conservative estimate for carbon prices during CP1.


Barringer J, Trotter C, Forrester G. Detecting change in potentially Kyoto-compliant shrubland area using the New Zealand Land Resource Inventory. Landcare Research Contract Report LC0506/158 (in prep.).

Clough TJ, Buckthought LE, Kelliher FM, Sherlock RR 2007. Diurnal fluctuations of dissolved nitrous oxide (N2O) concentrations and estimates of N2O emissions from a spring-fed river: implications for IPCC methodology. Global Change Biology 13: 1016-1027.

Ministry for the Environment 2007. Projected balance of emission units for the First Commitment Period of the Kyoto Protocol. Publication No. 808. Wellington, Ministry for the Environment.

Sutherland A, Trotter C, Payton I, Shepherd J, Marden M 2006. Estimating Kyoto-compliant Crown Land available for afforestation. Landcare Research Contract Report LC0607/050. 24 p.

Trotter CM, Tate KR, Scott NA, Townsend JA, Wilde RH, Lambie S, Marden M, Pinkney EJ 2005. Afforestation/reforestation of New Zealand marginal pastoral lands by indigenous shrublands: the potential for Kyoto forest sinks. Annals of Forest Science 62: 865-871.