• Climate Change
• Legislation & regulations
• Forestry emissions trading scheme
• Other sustainable forestry initiatives
• Agriculture emissions trading scheme
• International climate change
• Sustainable land management
  • Investment sheets
  • Plan of action
  • Questions & answers
  • Research grants
• Staying informed
• Background reports & analysis
• Previous consultation & background information

Enhanced modelling capability to conduct impact assessments

Authors: Paul Newton; Jeremy Bryant; Val Snow; Mark Lieffering

Download the full report in PDF format [PDF 669KB]

Executive summary

There is an urgent need for N.Z. to enhance its ability to conduct comprehensive impact assessments for pastoral agriculture under projected global change scenarios. The kind of assessment we see as being necessary has not been carried out before and should have the following characteristics:

1. impacts will be assessed at the farm level as this is where the decision making for adaptation will occur.
2. climate projections will include climate variability and will provide a block of weather data (for 5 year or longer periods) allowing us to move away from simplistic single mean annual changes and assess the true impacts of climate change on farms systems and their capacity to recover from extreme events.
3. projections of forage supply (pasture growth and feed quality), nitrogen and irrigation use will be made using an ecosystem model that includes the most up-to-date understanding of climate change impacts on ecosystem function. Our understanding of the biology of systems under climate change has increased markedly over the last five years.
4. information on pests and diseases that will influence forage supply will be included in the forage supply assessment.
5. using the forage supply information plus information on animal heat stress, we will run farm system models to produce yearly meat, milk and wool sales and financial data; these simulations will include detailed exploration of management options such as calving and lambing dates, fertiliser and irrigation use, stocking rate etc.
6. where management is not optimal in the future environment we will explore potential adaptive possibilities linking these options to social science research that will consider adoption.
7. animal performance and fertiliser information from these simulations will then be used within OVERSEER® to model environmental impacts such as greenhouse gas emissions, nitrogen and phosphorus losses.

Contact for Enquiries

Sustainable Land Management and Climate Change
MAF
Pastoral House
25 The Terrace
PO Box 2526, Wellington
Tel: 0800 CLIMATE (254 628)
Contact this person