1. Duty of care for protecting Torres Strait Islanders from climate harms
   The Uncles’ lawyers argued that the Australian Government had a duty of care to protect Torres Strait Islanders from climate harms, despite the global nature of climate change. 
   
   Fiona McLeod SC for the Uncles argued that Australia’s setting of emissions reduction targets impacts collective action, influencing what other nations do:
   “There is no scientific doubt, as I’ve said, that every increment, every additional tonne, every fraction of a tonne of GHG emissions, has an effect on the climate system…”
   
   “...if all countries exceeded their greenhouse gas emissions fair share in the same way that Australia has, then the prospects of remaining within the global budget would totally disappear”.
   
   The Government argued that they don’t have a duty of care. It said it is generally required to “do what it can” to “reduce greenhouse emissions and prepare Australia and its citizens to adapt to climate change” and that this can’t be interpreted as a duty. 
    
2. Emissions reductions targets and the best available science
   The Uncles argued that the Commonwealth should have identified climate change impacts in the Torres Strait and set a best available science target to mitigate the most dangerous of those impacts. 
   
   The Commonwealth argued that under the law, they were not required to consider the best available science or the impacts of climate change at different emissions scenarios when setting emissions reduction targets, and said that it was reasonable for them to not consider these factors.
   
   The Judge said:
    “...the inference I would draw from the [PM&C UNFCCC] taskforce report is that the Climate Change Authority report and the climate science was… in the lowest order of priority in what the Government actually took into account when setting its targets…if they [the Government] had been more frank and honest with the public, they could have come out and said that economic growth and all these things were more important than the climate science and the Climate Change Authority…it just doesn’t look like they had a great deal of regard to climate science, to me, anyway.”
   
   The Judge asked the Commonwealth, “In some respects…your case is that it would be open to the Commonwealth Government to set an emissions reduction] target which completely ignores that climate science and that it would not be held accountable by the law of negligence?” and Stephen Lloyd SC responded, “Absolutely”. 
   
   Mr Lloyd SC argued that the Executive Government does not have a duty of care to choose a reasonable target. He said that setting a target is a core policy issue, in relation to which the Court is not equipped to assess.
    
3. The evidence of Torres Strait Islanders about climate impacts
   Stephen Lloyd SC for the Commonwealth argued that the lay witnesses from the Torres Strait could only comment on what they had observed in their environment but that their observations weren't sufficient to prove that climate change was occurring.
   
   The Uncles' lawyers disagreed, with Fiona McLeod SC saying: 
   “That proposition, we submit, ought to be categorically rejected. These witnesses spoke of their observations with undisputed cultural authority, the result of lifetimes of careful observation of and care for country, with the benefit of deep learning. The accumulated wisdom of generations shaped by their interactions with land and waters…the hasty dismissal of this evidence and its importance is inappropriate. There should be no question that the quality of this evidence is at least as important and weighty as the expression of expert opinions based upon assumed facts, recorded data and expert analysis.”
    
4. Mitigating impacts of climate change 
   The Commonwealth said that they don’t have a duty of care to mitigate climate harms in the Torres Strait, because Torres Strait Islanders could take steps to protect themselves from climate impacts, including by doing things such as sandbagging. 
   
   The Judge said:
   “There’s a bit of an air of unreality to say that filling sandbags, or putting tractor tyres out, or building rubble is really something that practically can protect the Islanders from climate change, or raising their houses on stilts. I suspect if you said that to the citizens of Colloroy that they can raise their houses on stilts, they might say, well the practicality of that. I understand that you can say that they can do something, but there is an air of unreality with what the evidence reveals and what they have been forced to do in the past.”
    
5. Loss of culture
   The Uncles said that unless serious and urgent action on climate is taken by the Commonwealth, it is highly likely that Torres Strait Islanders will be forced to leave their homelands by 2050 and lose their culture (Ailan Kastom). 
   
   The Commonwealth said that cultural loss could not be compensated, and the loss of Ailan Kastom is in the same category as personal injury cases.
   
   Stephen Lloyd SC argued that mere sadness alone cannot be compensated and that Torres Strait Islanders should not be compensated for the loss of Ailan Kastom. In doing so, he put the loss of Ailan Kastom in the same category as the mere sadness that personal injury law would not recognise or compensate.

Uncle Pabai and Uncle Paul are seeking orders from the court that require the Federal Government to take steps to prevent this harm to their communities, including cutting greenhouse gas emissions in line with the best available science. The Australian Government currently has a 2050 ‘net zero’ emissions target, which experts say will not be enough to prevent disaster in the Torres Strait. In fact, leading climate scientists on the Climate Targets Panel calculate that Australia’s greenhouse emissions need to be reduced by 74% by 2030 (from 2005 levels) and to net zero by 2035 to keep global heating to below 1.5°C and avert the destruction of Torres Strait Islander communities.