RELEASED UNDER THE OFFICIAL INFORMATION ACT
This review does not address the issue of climate change impacts on New Zealand. That is to say, it does not examine the impact of changes in rainfall patterns and temperature, increasing risk of floods and droughts, rising sea levels, and increasing frequency and intensity of extreme weather events on infrastructure, the agricultural sector, ecosystems and the built environment (New Zealand, Ministry for the Environment 2001, 2004a, 2004b; Mullan et al, 2005).
However, a number of greenhouse gas mitigation actions have clear links with the complementary need to adapt to the expected impacts of climate change. This section outlines those links to enable a full consideration of the co-benefits of both adaptation and mitigation measures, and of national or regional policies that could support both outcomes.
It also points to areas where mitigation-related decisions could potentially change the vulnerability of society or ecosystems to the impacts of climate change, or where adapting to the impacts of climate change could lead to changes in greenhouse gas emissions.
Synergies and mutual co-benefits of mitigation and impacts/adaptation
To some extent, there are feedback loops from climate change that should reduce the causes of climate change, stabilising the environment. A number of the expected impacts of climate change can have the positive effect of also reducing greenhouse gas emissions and/or increasing carbon sinks. For example:
- higher average winter temperatures would reduce winter heating demand
- greater snow melt and increased winter rainfall would lead to relatively greater storage levels in hydro lakes during winter, which should result in reduced interannual variations in CO2 emissions from supplementary thermal power generation during winter
- increased risk of erosion of hills and changes in economic agricultural viability of some regions could prompt greater rates of afforestation.
At the same time, a number of measures designed primarily to reduce greenhouse gas emissions can also make society, ecosystems and the economy more resilient against the expected effects of climate change. For example:
- higher levels of insulation in houses for energy-saving purposes improve resilience to summer peak temperatures and may reduce vulnerability to extreme weather events
- distributed generation systems using local energy resources are likely to be more resilient against failures of power systems due to weather.
Barriers, trade-offs and adverse effects
However, there is also scope for vicious circles in which climate change impacts add to the causes of climate change, leading to increased energy demand and greenhouse gas emissions, or increased risks to carbon sinks and renewable energy resources. For example:
- drier conditions in eastern regions could lead to increased energy demand from more irrigation systems
- higher peak summer temperatures are expected to lead to increased energy demand for air-conditioning systems
- changing areas for optimal primary production could lead to a greater distance between production areas and existing processing centres, resulting in increased demand for transport of raw products or the need to relocate processing centres
- higher temperatures and increased risk of drought could lead to increased biosecurity and fire risks to existing forest sinks
- an increase in more drought-resistant but lower-quality pastures could lead to increased methane emissions intensity from agricultural production
- increased interannual climate variability could increase occasions when low winter hydro lake levels need to be supplemented by additional thermal power generation
- expansion of forest sinks and bioenergy systems could increase vulnerability to the effects of climate change if the expansion is into areas that may become more susceptible to biosecurity risks, fire and drought under a warmer and drier climate.
What policies best capture co-benefits and avoid adverse spill-over effects between mitigation and adaptation?
The above section provides a qualitative outline of some of the co-benefits and adverse spill-over effects. Quantitative knowledge about the strength and importance of those links for sectors, regions and the economy as a whole is limited and depends on the specific issue under consideration.
Generally, these linkages can best be incorporated into decision-making by ensuring that consideration of likely climate change becomes part of standard planning and risk-assessment practices. The Ministry for the Environment has produced a series of guidance documents that help stakeholders understand the likely changes in climate and to apply a sequential risk-assessment approach to evaluate whether these changes could materially affect their operations.
Such risk assessments are particularly important whenever decisions are made about long-lived infrastructure and assets that are exposed to climatic conditions in any way, or that provide a service to meet a climate-driven demand. Routine climate change risk assessments in planning processes by industry and local and central government would help avoid lock-in of technologies and practices that are vulnerable to hazards that could be exacerbated by climate change, or that rely on natural resources or energy supply and demand that could be significantly affected by climate change. An assessment of the relevance of climate change in the context of other drivers and pressures can usually be taken only at a local level, where priorities and risks can be appropriately weighed up (New Zealand, Ministry for the Environment, 2004c).
Current and future work by the Government in this area concentrates on:
- working with science organisations to increase the availability of appropriate research findings to central and local government and other sector groups
- ongoing provision of basic information to decision-makers on climate change impacts, adaptation options and the potential costs and benefits of preparing for climate change
- partnering with stakeholders and helping them use this information as appropriate.
Specific further technical work on links between the impacts of climate change and greenhouse gas emissions could include:
- improved modelling of the impacts of climate change on hydropower resources
- changes in energy demand in urban and rural areas under a changing climate, including climate variability and extremes
- assessing long-term viability of areas for optimal forestry and bioenergy production, and options to protect such investments against biosecurity, fire and drought risks.
Specific technologies that can assist adaptation to the effects of climate change should also be designed with greenhouse gas mitigation objectives in mind; eg, irrigation systems that minimise energy consumption, and breeding of new pastures that are adapted to higher carbon dioxide concentrations and drought conditions as well as assist in reducing non-CO2 greenhouse gas emissions.