New Zealand’s changing climate and oceans: The impact of human activity and implications for the future

New Zealand’s changing climate and oceans: The imp…
01 Jun 2013

The purpose of this report is to provide New Zealand with an update on the current scientific understandings of climate change and the ways in which it is likely to affect New Zealand over coming years and decades. My Office has been assisted by some of New Zealand’s leading climate scientists in preparing this report. The report focuses particularly on describing likely effects on various regions of New Zealand and explains why only considering predicted average changes leads to an underestimation of the impact of predicted climate change on our environment and economy.

The science of climate change is both complex and evolving, and it can therefore be difficult for the layperson and policy maker to navigate. Nevertheless, it is important that we all have an understanding of the most likely scenarios ahead as greenhouse gases continue to accumulate in our oceans and atmosphere. Climate change and associated ocean acidification have the potential to affect New Zealand directly and indirectly over the coming years. Many decisions will be required at both national and local levels, and within both the public and private sectors. These decisions will need to be made in the face of inevitable and unresolvable degrees of scientific uncertainty.

An inherent feature of climate change science is its complexity and it must deal with many unknowns. Considerable research into the effects of greenhouse gases has been undertaken globally and, despite inevitable uncertainty, there is a very high scientific consensus regarding the likely magnitude, approximate timing of and the nature of the challenges ahead. It would be highly imprudent to ignore such projected scenarios just because they must be expressed in terms of probabilities rather than certainties. It is important to apply an understanding of uncertainty and of risk and their management to address this challenge and this means using the available and accumulating evidence appropriately. Just because there is an inherent level of uncertainty does not obviate the probability of impactful climate change and the need to be proactive in addressing it through mitigation and adaptive strategies.

This report intentionally does not address questions of what policy actions should be taken in response to the currently available knowledge on the future of the global and regional climate. The key decision of when and how to respond to climate change falls beyond the scope of this report, not least because it involves considerable reflection about societal values. It will be necessary for New Zealand to address a number of challenges that have both a scientific and value component. These include:

  • What is an acceptable level of climate-related risk to society?
  • What are the costs and benefits of adaptation or mitigation compared with other priorities?
  • How are different stakeholders affected, (either now or in the future)?

Across these considerations, there are also questions relating to inter-generational equity and international responsibility. These are among the policy-relevant questions that are, and will need to be, addressed. Science can inform these, but cannot alone answer them.

Page last modified: 15 Mar 2018