Attempts to sue polluting companies and governments over their responsibility for climate change would have a greater chance of success if they made better use of the latest science, according to a study by Oxford University researchers.
The paper, published in the journal Nature Climate Change, finds that the growing ability of scientists to link emissions with specific damages caused by climate change, known as attribution science, could provide further evidence in lawsuits against the world’s biggest emitters.
Litigation has become an increasingly important tool for campaigners seeking to force governments and companies to curb emissions and redress the injustices at the heart of the climate crisis.
There have been more than 1,500 climate-related lawsuits around the world to date and some high-profile cases have succeeded. Last month, a Netherlands court ordered Anglo-Dutch oil giant Shell to cut its carbon dioxide emissions by 45 percent by 2030, and in April a German court ruled that the country’s climate targets were insufficient and therefore partly unconstitutional.
However, attempts to hold emitters to account for climate-related damages in court have largely failed because plaintiffs have not been able to link definitively the harms caused by climate change with greenhouse gas emissions.
The new study from the Oxford Sustainable Law Programme and Environmental Change Institute, Filling the evidentiary gap in climate litigation, finds that many lawsuits have not used the latest advances in attribution science as evidence.
Attribution science studies how greenhouse gas emissions contribute to specific extreme events such as storms, droughts, heatwaves or floods as well as slower changes in average temperature and rainfall.
For example, recent research found that human-caused sea-level rise increased the damages suffered when Hurricane Sandy hit the US East Coast in 2012 by $8.1 billion. Another study found that climate change was responsible for $67 billion of damage caused by Hurricane Harvey, which hit Texas in 2017.
Such evidence is essential when trying to claim compensation in court because plaintiffs have to show a direct causal link between their injury and the defendant’s behaviour.
‘Science Has Moved On’
The study reviewed 73 climate litigation cases against polluters across 14 jurisdictions. It found most did not quantify the extent to which climate change was responsible for the climate-related events affecting the plaintiffs. Even fewer provided quantitative evidence linking defendants’ emissions with their injuries. Some claimed there was a climate change link without providing any evidence.
Dr Friederike Otto, associate director of Oxford’s Environmental Change Institute, said that, to change the fate of most climate litigation, “courts and plaintiffs alike have to realise that science has moved on from ascertaining that climate change is potentially dangerous to providing causal evidence linking emissions to concrete damages”.
The paper concludes that better use of the latest attribution science could improve the chances of lawsuits seeking compensation for losses, regulatory action and emission cuts. It could also help lawyers decide when a case is weak and not worth pursuing.
When combined with evidence showing the volume of greenhouse gas emissions released by the world’s most polluting companies and research calculating the proportion of temperature increase and sea-level rise and level of ocean acidification that can be attributed to emissions from individual companies, it could even help activists sue individual fossil fuel firms.
“The power of climate litigation is increasingly clear”, said lead author Rupert Stuart-Smith. “If litigation seeking compensation for losses suffered due to climate change is to have the best chance of success, lawyers must make more effective use of scientific evidence.
“Climate science can answer questions raised by the courts in past cases and overcome hurdles to the success of these lawsuits.”
