5. Conclusion

In this chapter we have explored some of the ways in which concepts, principles and rules from evidence law are engaged and discussed in climate litigation. At the same time, some recent cases demonstrate that evidentiary rules and categories could be expanded and developed in productive ways. The increasing number and breadth of climate cases also presents an opportunity to reflect on some of the fundamental concepts that underpin evidence law, including relevance, reliability and the nature of ‘knowledge’. If the goal of the UEL has been to ensure that all relevant and admissible evidence is before the fact finder, the complex, and sometimes novel, claims raised in climate litigation offer a lens through which to understand how some of the traditional rules of evidence have worked to narrow the role of courts, as well as creating hierarchies when it comes to witnessing and accounting for the impacts of climate change. For example, an Aboriginal or Torres Strait Islander witness may be more likely to be characterised as a ‘lay’ witness even when they, arguably, possess specialised knowledge about relevant laws and customs. A further challenge has been posed by the potential role in climate cases for ‘civic evidence’ or ‘citizen science’, as some commentators argue for the development of frameworks that will enable those affected by climate change to offer evidence of their direct experience of the negative impacts of climate change.^[1] Traditional frameworks and divisions between ‘expert’ and ‘lay’ witnesses do not easily accommodate this category of knowledge. The challenge for lawyers working in this growing area of practice will be to find the gaps and opportunities to develop and expand the law to better accommodate these new forms of knowledge.